Johnson v. Secretary of Health and Human Services

In the United States Court of Federal Claims

OFFICE OF SPECIAL MASTERS

Filed: December 23, 2025

*************************

ROBERTA JOHNSON, * PUBLISHED

*

Petitioner, * No. 22-107V

*

v. * Special Master Nora Beth Dorsey

*

SECRETARY OF HEALTH * Ruling on Entitlement; Measles-Mumps-

AND HUMAN SERVICES, * Rubella (“MMR”) Vaccine;

* Sudden Onset Sensorineural Hearing

Respondent. * Loss (“SSNHL”); Autoimmune Inner Ear

* Disease (“AIED”).

*************************

Ronald Craig Homer, Conway, Homer, PC, Boston, MA, for Petitioner.

James Vincent Lopez, U.S. Department of Justice, Washington, DC, for Respondent.

RULING ON ENTITLEMENT 1

On February 2, 2022, Roberta Johnson (“Petitioner”) filed a petition for compensation

under the National Vaccine Injury Compensation Program (“Vaccine Act” or “the Program”), 42

U.S.C. § 300aa-10 et seq. (2018), 2 alleging a measles-mumps-rubella (“MMR”) vaccine

administered on April 19, 2019, caused her to develop bilateral sudden onset sensorineural

1

Because this Ruling contains a reasoned explanation for the action in this case, the undersigned

is required to post it on the United States Court of Federal Claims’ website and/or at

https://www.govinfo.gov/app/collection/uscourts/national/cofc in accordance with the E-

Government Act of 2002. 44 U.S.C. § 3501 note (2018) (Federal Management and Promotion of

Electronic Government Services). This means the Ruling will be available to anyone with

access to the Internet. In accordance with Vaccine Rule 18(b), Petitioner has 14 days to

identify and move to redact medical or other information, the disclosure of which would

constitute an unwarranted invasion of privacy. If, upon review, the undersigned agrees that the

identified material fits within this definition, the undersigned will redact such material from

public access.

2

The National Vaccine Injury Compensation Program is set forth in Part 2 of the National

Childhood Vaccine Injury Act of 1986, Pub. L. No. 99-660, 100 Stat. 3755, codified as amended,

42 U.S.C. §§ 300aa-10 to -34 (2018) (“Vaccine Act” or “the Act”). All citations in this Ruling to

individual sections of the Vaccine Act are to 42 U.S.C.A. § 300aa.

1

hearing loss (“SSNHL”) and autoimmune inner ear disease (“AIED”). 3 Petition at Preamble

(ECF No. 1). Respondent argued against compensation, stating “this case is not appropriate for

compensation under the Vaccine Act.” Respondent’s Report (“Resp. Rept.”) at 2 (ECF No. 22).

After carefully analyzing and weighing the evidence presented in accordance with the

applicable legal standards, 4 the undersigned finds Petitioner has provided preponderant evidence

that the MMR vaccine she received on April 19, 2019 caused her to develop AIED, satisfying

Petitioner’s burden of proof under Althen v. Secretary of Health & Human Services, 418 F.3d

1274, 1280 (Fed. Cir. 2005). Accordingly, Petitioner is entitled to compensation.

I. ISSUES TO BE DECIDED

The parties agree on Petitioner’s diagnosis of AIED. Joint Submission at 1.

The parties dispute all three Althen prongs. Joint Submission at 2. Specifically,

Respondent disputes that Petitioner has shown that “administration of an MMR can cause the

injuries alleged;” disputes that there is a “logical sequence of cause and effect between

[Petitioner’s] April 19, 2019 MMR vaccination and her subsequent injuries;” and disputes that

there is “an appropriate temporal relationship between [Petitioner’s] April 19, 2019 MMR

vaccination and the onset of her injuries.” Id.

II. BACKGROUND

A. Procedural History

On February 2, 2022, Petitioner filed a petition requesting compensation followed by

medical records and affidavits. 5 Petitioner’s Exhibits (“Pet. Exs.”) 1-7. The case was then

assigned to the undersigned. Notice of Assignment dated Apr. 26, 2022 (ECF No. 12).

Respondent filed a Rule 4(c) report on November 15, 2022, arguing against compensation.

Resp. Rept. at 1.

3

While the petition only alleges Petitioner developed SSNHL, subsequent filings specify that

Petitioner developed AIED. See, e.g., Joint Submission, filed Sept. 30, 2024, at 1 (ECF No. 70).

4

While the undersigned has reviewed all of the information filed in this case, only those filings

and records that are most relevant will be discussed. See Moriarty v. Sec’y of Health & Hum.

Servs., 844 F.3d 1322, 1328 (Fed. Cir. 2016) (“We generally presume that a special master

considered the relevant record evidence even though he does not explicitly reference such

evidence in his decision.”); see also Paterek v. Sec’y of Health & Hum. Servs., 527 F. App’x

875, 884 (Fed. Cir. 2013) (“Finding certain information not relevant does not lead to—and likely

undermines—the conclusion that it was not considered.”).

5

Petitioner continued to file medical records throughout litigation.

2

On June 29, 2023, Petitioner filed an expert report from Dr. Edwin M. Monsell. Pet. Ex.

11. On December 27, 2023 and January 26, 2024, Respondent filed expert reports from Dr.

Herman F. Staats and Dr. Yu-Lan Mary Ying. Resp. Exs. A, C.

The undersigned held a Rule 5 conference on March 21, 2024. Order dated Mar. 21,

2024 (ECF No. 55). She advised that parties that she had “adjudicated several SNHL cases and

has previously found it difficult for petitioners to show the hearing loss was autoimmune and that

it was caused by a vaccine.” Id. at 2. However, she explained the present case was “different

from past cases because the experts agreed Petitioner’s diagnosis is an autoimmune hearing loss

(AIED) and agreed as to Althen prong three.” Id. The undersigned noted the “case merits

consideration for settlement given that there is risk for both parties” and noted the case could be

resolved without an entitlement hearing. Id.

On July 24, 2024, Respondent filed a joint status report advising that he was not

amenable to settlement discussion in this case. Joint Status Rept., filed July 24, 2024 (ECF No.

66). The parties requested the undersigned set a briefing schedule for a ruling on the record. Id.

Petitioner filed his motion for a ruling on the record on September 30, 2024. Pet. Motion

for a Ruling on the Record (“Pet. Mot.”), filed Sept. 30, 2024 (ECF No. 73). Respondent filed

his responsive brief on January 21, 2025, and Petitioner filed a reply on March 5, 2025. Resp.

Response to Pet. Mot (“Resp. Response”), filed Jan. 21, 2025 (ECF No. 80); Pet. Reply to Resp.

Response (“Pet. Reply”), filed Mar. 5, 2025 (ECF No. 81).

This matter is now ripe for adjudication.

B. Medical Terminology

1. Autoimmune Inner Ear Disease

AIED is “a condition of a bilateral sensorineural hearing loss [(“SNHL”)], caused by an

‘uncontrolled’ immune system response.” Resp. Ex. C, Tab 18 at 1; 6 see also Resp. Ex. C, Tab

19 at 13 tbl.7, 16. 7 “AIED is considered to be responsible for [less than] 1% of all SNHL cases.”

Resp. Ex. C, Tab 18 at 1.

“The clinical expression of AIED is a progressive bilateral and not always symmetric

SNHL, progressively developing between [three] and 90 days, which typically benefits from []

steroid and immunosuppressive therapy.” Resp. Ex. C, Tab 18 at 1. Often only one ear is

affected in the early stage. Id. at 3. “The hearing deficit sometimes presents [with] threshold

6

Andrea Ciorba et al., Autoimmune Inner Ear Disease (AIED): A Diagnostic Challenge, 32 Int’l

J. Immunopathol. & Pharmacol. 1 (2018).

7

Sujana S. Chandrasekhar et al., Clinical Practice Guidelines: Sudden Hearing Loss (Update),

161 Otolaryngol. Head & Neck Surg. s1 (2019).

3

fluctuations.” Id. In 25-50% of cases, tinnitus 8 can be present. Id. Importantly, “there are no

standardized diagnostic criteria or reliable diagnostic tests for the diagnosis of AIED.” Id. at 1.

As such, the diagnosis of “immune-mediated cochleovestibular disorders” is based on clinical

symptoms, laboratory tests (“demonstrating the presence in the serum of antibodies or activated

T cells against inner ear antigens”), and on the response to immunosuppressive treatment. Id. at

3. “Essentially, AIED is a diagnosis of exclusion, suspected in case of a documented progressive

SNHL, when other etiologic causes have been ruled out.” Id.

2. Sensorineural Hearing Loss

SNHL is “[h]earing loss resulting from abnormal function of the cochlea, auditory nerve,

or higher aspects of central auditory perception or processing.” Resp. Ex. C, Tab 19 at 4 tbl.1.

SNHL is “generally idiopathic,” but some cases are “associated with infections, vasculitides,

tumors, [] genetic conditions, and cardiovascular risk factors.” Resp. Ex. A, Tab 3 at 2. 9

SSNHL is a subset of SNHL that “occurs within a 72-hour window” and meets specific

audiometric criteria. Resp. Ex. C, Tab 19 at 3. “Possible etiologies of SSNHL include viral

infection, vascular compromise, autoimmune disease, inner ear pathology, and central nervous

system pathophysiology.” Id. at 16. Idiopathic SSNHL has “no identifiable cause despite

investigation” and accounts for “90% of patients with SSNHL.” Id. at 3.

C. Factual History

1. Summary of Medical Records 10

On March 15, 2019, Petitioner received an MMR vaccine at the Northwestern Medicine

(“NM”) employee health office in Winfield, Illinois. Pet. Ex. 1 at 1. Petitioner was employed as

an operating room nurse at NM Central DuPage Hospital. See, e.g., Pet. Ex. 2 at 1105. On April

19, 2019, 35 days later, Petitioner received a second dose of the MMR vaccine. Pet. Ex. 1 at 1.

She was sixty-five years old at the time of the vaccinations. Id. Petitioner’s medical history

prior to receiving the MMR vaccines was unremarkable. See, e.g., Pet. Ex. 2 at 1400-16, 1512-

30 (documenting routine annual visits).

On May 25, 2019, 36 days after receiving a second dose of MMR vaccine, Petitioner

presented to NM urgent care, reporting “bilateral ear fullness” beginning “[four to five] days

8

Tinnitus is “a noise in the ears, such as ringing, buzzing, roaring, or clicking. It is usually

subjective in type.” Tinnitus, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=50114 (last visited Dec. 17, 2025).

9

Roger Baxter et al., Sudden-Onset Sensorineural Hearing Loss After Immunization: A Case-

Centered Analysis, 155 Otolaryngol. Head & Neck Surg. 81 (2016).

10

This summary of medical records is taken from the parties’ briefs, with edits from the

undersigned, as the undersigned finds they provided an accurate representation of the records.

See Pet. Mot. at 4-30; Resp. Response at 3-9.

4

ago.” Pet. Ex. 2 at 1365. She reported she had “flown and been in [the] ocean [four] times over

the past ‘few weeks.’” Id. She reported taking decongestants without relief. Id. On

examination, her tympanic membranes 11 were “dull” bilaterally with no other significant

findings. Id. at 1367. She was diagnosed with bilateral acute serous otitis media, 12 prescribed

Flonase, and encouraged to continue taking decongestants. Id. at 1368.

On June 4, 2019, Petitioner underwent an audiogram at NM, which showed moderate

bilateral SNHL. Pet. Ex. 5 at 1. According to Petitioner’s declaration, the audiogram was

ordered by ear, nose, and throat specialist (“ENT”) Riddhi Patel, M.D., at NM. Pet. Ex. 6 at ¶ 4.

Petitioner states that she knew Dr. Patel from her work in the hospital and was also informally

examined by Dr. Patel on June 4, 2019; however, Dr. Patel’s examination was not formally

documented in the medical records. Id.; see also Pet. Mot. at 6 n.5.

On June 5, 2019, Petitioner saw neuro-ophthalmologist Jeffrey Haag, M.D., at the

Wheaton Eye Clinic, reporting the “sudden loss of hearing bilaterally [two] weeks ago [and]

trouble with balance.” Pet. Ex. 3 at 25. Petitioner reported that her symptoms “began after an

airplane flight.” Id. Dr. Haag noted Petitioner’s prior appointment with Dr. Patel, who found

bilateral hearing loss. Id. The eye examination showed mild nuclear sclerosis 13 bilaterally but

was otherwise normal. Id. at 26-27. Dr. Haag’s impression was “[d]izziness and decreased

hearing (bilateral, symmetrical), cause uncertain.” Id. at 25.

Dr. Haag later added an undated addendum to his chart note, indicating that he had

consulted with neurotologist Andrew Fishman, M.D., who reviewed Petitioner’s audiogram from

the day prior and believed it was consistent with bilateral SNHL. Pet. Ex. 3 at 25. Per Dr.

Fishman’s recommendation, Dr. Haag started Petitioner on prednisone 14 60 mg daily. Id.

11

The tympanic membrane, also called the eardrum, is “the obliquely placed, thin membranous

partition between the external acoustic meatus and the tympanic cavity.” Membrana Tympanica,

Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/dorland/

definition?id=88565 (last visited Nov. 4, 2025).

12

Otitis media is “inflammation of the middle ear.” Otitis Media, Dorland’s Med. Dictionary

Online, https://www.dorlandsonline.com/dorland/definition?id=95455 (last visited Nov. 4,

2025). Serous otitis media is “chronic otitis media marked by serous effusion into the middle

ear.” Otitis Media, Serous, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=95462 (last visited Nov. 4, 2025).

13

Nuclear sclerosis, or nuclear cataract, refers to a congenital or degenerative opacity within the

central portion of the lens. Leila M. Khazaeni, Cataract, Merck Manual, https://www.merck

manuals.com/professional/eye-disorders/cataract/cataract (last visited Dec. 16, 2025). “The main

symptom is gradual, painless vision blurring.” Id.

14

Prednisone is “a synthetic glucocorticoid [i.e. steroid] . . . [administered] as an

antiinflammatory and immunosuppressant in a wide variety of disorders.” Prednisone, Dorland’s

Med. Dictionary Online, https://www.dorlandsonline.com/dorland/definition?id=40742 (last

visited Nov. 4, 2025).

5

On June 12, 2019, Petitioner saw neurotologist Dr. Fishman at NM, reporting the onset of

bilateral hearing loss on May 22, 2019, associated with tinnitus, pressure in her ears, right ear

pain, dizziness, and headaches. Pet. Ex. 2 at 1340-41.

Also, on June 12, 2019, Petitioner underwent a second audiogram, which was unchanged

from the earlier study six days prior. Pet. Ex. 2 at 1331-32; Pet. Ex. 5 at 2. The audiologist

Krystine Mullins noted Petitioner had a family history of hearing loss, involving her father and

aunt. Pet. Ex. 2 at 1331-32.

On June 13, 2019, Petitioner underwent magnetic resonance imaging (“MRI”) of her

brain and internal auditory canals that showed a small meningioma 15 in the left occipital node

without any evidence of brain compression or mass effect. Pet. Ex. 2 at 1321-22.

On June 17, 2019, Petitioner saw ENT Seth Kay, M.D., for persistent vertigo. Pet. Ex. 2

at 1296. Dr. Kay noted Petitioner’s history of sudden onset bilateral SNHL and vertigo that

developed “[two] weeks ago after a flight.” Id. High-dose prednisone had improved Petitioner’s

hearing, but her vertigo persisted. Id. The ENT examination was normal. Id. at 1299. Dr. Kay

administered an intratympanic steroid injection in the right ear. Id. Dr. Kay’s diagnosis was

“[b]ilateral vertigo and hearing loss of unclear etiology.” Id. at 1300. The differential diagnoses

included bilateral Meniere’s disease, 16 bilateral labyrinthitis, 17 an autoimmune process, tumor, or

central nervous system process. Id. He referred Petitioner to a neurologist for further evaluation.

Id. Dr. Kay also noted Dr. Fishman “thought this was either bilateral Meniere’s or an

autoimmune process.” Id. at 1296.

On June 26, 2019, Petitioner underwent a third audiogram, which showed improved low

frequency hearing with otherwise moderate to severe bilateral SNHL. Pet. Ex. 2 at 1282; Pet.

Ex. 5 at 3. She was also evaluated again by Dr. Kay, complaining of right ear fullness that had

worsened when stopping diuretics for several days and improved after restarting them. Pet. Ex. 2

at 1268. Petitioner continued to report poor balance. Id. Dr. Kay favored a diagnosis of

Meniere’s disease given the improvement in her low frequency hearing, response to diuretics,

and minimal response to the middle ear steroid injection. Id. at 1272. Dr. Kay started to taper

Petitioner off prednisone and referred her to physical therapy (“PT”) for vestibular rehab. Id.

15

A meningioma is “a benign, slow-growing tumor of the meninges, usually next to the dura

mater.” Meningioma, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=30336 (last visited Nov. 4, 2025).

16

Meniere’s disease “is a clinical syndrome that consists of episodes of spontaneous vertigo

usually associated with unilateral fluctuating [SNHL], tinnitus, and aural fullness.” Pet. Ex. 39

at 2 (Jose A. Lopez‐Escamez et al., Diagnostic Criteria for Menière’s Disease, 25 J. Vestib.

Rsch. 1 (2015)).

17

Labyrinthitis is “inflammation of the internal ear; it may be accompanied by hearing loss or

vertigo.” Labyrinthitis, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=27360 (last visited Nov. 4, 2025).

6

On June 27, 2019, Petitioner had a PT evaluation for Meniere’s disease of both ears. Pet.

Ex. 2 at 1257. She reported a history that she “felt [her] ears were full as she came off a plane”

on May 22, 2019, with bilateral hearing loss that was worse on the right side. Id. Petitioner also

reported “[d]ifficult to tolerate busy visual stimulation” and dizziness. Id. Petitioner continued

to attend PT through November 26, 2019. Id. at 769-779, 816-26, 857-66, 918-48, 1039-41,

1052-60, 1084-91, 1152-77, 1247-63.

On July 10, 2019, Petitioner saw Dr. Fishman for a “follow up [regarding] [M]eniere’s

disease.” Pet. Ex. 2 at 1229. Petitioner reported that her vertigo had worsened since her last visit

and that she had obtained no relief from a right ear steroid injection. Id. She reported some

improvement of dizziness with PT. Id.

On July 11, 2019, Petitioner returned to Dr. Kay reporting worsening hearing since

stopping steroids. Pet. Ex. 2 at 1213. Dr. Kay noted that Dr. Fishman felt this was a progressive

autoimmune process. Id. The ENT examination was normal. Id. Dr. Kay diagnosed bilateral

hearing loss and vertigo of unclear etiology but “likely [AIED] given bilateral component and

only response to steroids.” Id. He restarted prednisone, continued vestibular rehab,

recommended hearing aids, and referred her to a rheumatologist. Id.

Also, on July 11, 2019, Petitioner underwent a fourth audiogram that showed a marked

decrease in hearing in the left ear. Pet. Ex. 2 at 1204; Pet. Ex. 5 at 5.

Petitioner next returned to Dr. Kay on July 25, 2019, and reported that she had obtained

hearing aids and her balance was slowly improving. Pet. Ex. 2 at 1134. Dr. Kay noted that

Petitioner had received MMR vaccines “[one to two] months before onset of symptoms” and that

there were “reports in the literature of similar vaccines causing hearing loss and vestibular

dysfunction.” Id. at 1134. He further stated that it was “unclear” whether the prior receipt of

MMR vaccine was “coincidental [versus] possible causation.” Id. at 1138. Dr. Kay’s

assessment remained “likely” AIED, and he noted Petitioner’s vertigo was severely limiting and

prevented her from returning to work. Id.

Later that day, Petitioner saw rheumatologist Brittany Panico, M.D., at NM, for an

evaluation of acute bilateral SNHL. Pet. Ex. 2 at 1104. Dr. Panico noted Petitioner’s vestibular

testing showed bilateral vestibular loss. Id. Petitioner continued “to have symptoms of

oscillopsia.” 18 Id. She continued to take prednisone, struggled with balance, and had

intermittent episodes of blurry vision. Id. In the history of the present illness, Dr. Panico noted

Petitioner “did receive MMR vaccine titers in March and April, approximately [one] month

before the onset of her hearing loss.” Id. at 1105. Further, Petitioner denied any rashes or skin

lesions or chemical exposure, nor recalled “any flulike symptoms, [upper respiratory infection]

symptoms[,] or recent infections.” Id. The physical examination was unremarkable besides a

18

Oscillopsia is “a symptom in which objects appear to wiggle, jerk, or move back and forth; it

sometimes accompanies nystagmus.” Oscillopsia, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=35681 (last visited Nov. 4, 2025).

7

positive Romberg’s sign. 19 Id. at 1107-08. Dr. Panico opined findings by “neuro-

ophthalmology, neurotology, [and] ENT” were “most consistent with autoimmune hearing loss”

but stated that Petitioner’s clinical features were “somewhat concerning for Cogan’s disease.” 20

Id. at 1110. Dr. Panico continued Petitioner’s prednisone taper and started her on methotrexate,

an immunosuppressive therapy. Id.

On August 1, 2019, Petitioner returned to neuro-ophthalmologist Dr. Haag, per a referral

from Dr. Panico, for an eye examination to rule out Cogan’s syndrome. Pet. Ex. 3 at 23.

Petitioner reported that her dizziness was worse since her last visit and that her “visual images

bounce a lot,” with intermittent vertical oscillopsia. Id. She had stopped driving in mid-June

2019. Id. The eye examination was normal and ruled out Cogan’s syndrome. Id. at 23-24. Dr.

Haag diagnosed Petitioner with “[v]estibular system dysfunction with bilateral hearing.” Id. at

23. He noted an “autoimmune etiology [was] suspected.” Id.

Petitioner had a follow up visit with Dr. Fishman on August 14, 2019. Pet. Ex. 2 at 1039.

Petitioner reported she was not sure if her dizziness was better and that she had periodic vision

changes. Id.

On August 27, 2019, Petitioner followed up with rheumatologist Dr. Panico for

autoimmune hearing loss. Pet. Ex. 2 at 994. Dr. Panico recommended Petitioner continue to

taper her prednisone. Id. at 1000. Her weekly methotrexate dosage was decreased due to

nausea. Id. The assessment remained SSNHL “concerning for autoimmune hearing loss.” Id.

On August 28, 2019, Petitioner saw neurosurgeon Andrew Chenelle, M.D., at NM, for

evaluation of the meningioma identified on her brain MRI. Pet. Ex. 2 at 978. Dr. Chenelle

believed the meningioma was an incidental finding unrelated to her current hearing loss and

balance problems. Id. at 981.

Later that day, Petitioner had a follow-up visit with Dr. Kay. Pet. Ex. 2 at 951. She

reported that her balance was slowly improving but she continued to have vertigo provoked by

visual and auditory stimuli. Id. Dr. Kay’s assessment remained “likely” AIED. Id. at 956.

Petitioner also underwent an audiogram. Id. at 968. Petitioner’s next follow-up with Dr. Kay

was October 2, 2019. Id. at 886-87. The assessment was unchanged. Id. at 899.

On October 3, 2019, Petitioner returned to Dr. Panico for follow-up of her autoimmune

hearing loss. Pet. Ex. 2 at 869. She advised Dr. Panico that she planned to resign from work “as

19

Romberg’s sign is the “swaying of the body or falling when standing with the feet close

together and the eyes closed.” Romberg Sign, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=106448 (last visited Nov. 4, 2025).

20

Cogan’s syndrome is “a rare autoimmune disease involving the eye and the inner ear.”

Vatinee Y. Bunya, Cogan Syndrome, Merck Manual, https://www.merckmanuals.com/

professional/eye-disorders/corneal-disorders/cogan-syndrome (last visited Nov. 5, 2025).

8

she feels this is the best decision for her.” 21 Id. She noted her father was also ill and receiving

hospice care and that she wanted to spend more time with him. Id. Petitioner reported that she

continued to experience vertigo in loud environments. Id. Dr. Panico’s assessment remained

SSNHL “concerning for autoimmune hearing loss.” Id. at 874.

On October 14, 2019, Petitioner saw optometrist Ann Clark, M.D., at Wheaton Eye

Clinic, complaining of blurry vision in her right eye along with “intermittent loss of vision, loss

of hearing, and loss of equilibrium.” Pet. Ex. 3 at 21. Petitioner reported she had to suppress her

right eye vision to see clearly. Id. at 21. Dr. Clark diagnosed diplopia (double vision). Id. at 22.

On November 6, 2019, Petitioner saw neurologist Timothy Hain, M.D., at Chicago

Dizziness and Hearing. Pet. Ex. 2 at 792. In the history of present illness, Petitioner reported

sudden onset of bilateral hearing loss on May 22, 2019, which worsened over the next two

weeks. Id. at 794. She said that her symptoms persisted despite treatment with prednisone and

methotrexate and that she had been unable to work as an operating room nurse since June 7,

2019. Id. Petitioner reported that she lost her balance easily in low light situations and that her

dizziness was triggered or worsened by rapid head movements, walking in poor lighting,

traveling in a car, and loud noises or bright lights. Id. She reported that her vertigo started

around June 5, 2019. Id. She had fallen three times due to her disequilibrium. Id. She also

reported that she had been diagnosed with oscillopsia and that her vision worsened around loud

noises. Id. On examination, Petitioner was unable to stand “in eyes closed tandem [R]omberg

for [six] seconds,” but her gait was otherwise unaffected. Id. at 804. She had “very slight

horizontal nystagmus.” 22 Id. Vestibulo-ocular reflex 23 “was very poor in all [three] directions.”

Id.

Dr. Hain diagnosed Petitioner with a “presumed” AIED (noting that “Cogan’s still seems

possible”), bilateral vestibular loss, and bilateral hearing reduction. Pet. Ex. 2 at 792. Dr. Hain

provided a detailed impression:

[Petitioner] is a very unusual patient with a recent onset of complete

vestibular loss and partial bilateral vestibular loss. Her presumptive diagnosis is

[AIED], although there has not been an autoimmune disease identified (as yet).

21

Petitioner resigned from her job at NM on October 19, 2019. Pet. Ex. 2 at 829.

22

Nystagmus is “involuntary, rapid, rhythmic movement of the eyeball.” Nystagmus, Dorland’s

Med. Dictionary Online, https://www.dorlandsonline.com/dorland/definition?id=34565 (last

visited Nov. 4, 2025).

23

Vestibulo-ocular reflex is “nystagmus or deviation of the eyes in response to stimulation of the

vestibular system by angular acceleration or deceleration or when the caloric test is performed

(irrigation of the ears with warm or cool water or air).” Vestibuloocular Reflex, Dorland’s Med.

Dictionary Online, https://www.dorlandsonline.com/dorland/definition?id=103130 (last visited

Dec. 16, 2025).

9

The rarest aspect to her situation is her bilateral vestibular loss, which has

a prevalence of about 1/25,000 in the general population. . . . This combined with

bilateral sensorineural hearing loss is even more uncommon, and the only cases I

have seen in the last 30 years with a similar picture were again attributed to

[AIED]. [Petitioner] does not have a history of exposure to an ototoxic

medication such as an aminoglycoside.

[Petitioner] does not have Meniere’s disease—although her hearing

resembled Meniere’s at the beginning, Meniere’s does not have this pattern of

complete vestibular loss over a short time.

The associations of this syndrome with autoimmune disorders include

nearly [all] known autoimmune illness, but primarily there are reports in Cogan’s,

[ulcerative colitis (“UC”)], Wegener’s, Ankylosing spondylitis [(“AS”)],

relapsing polychondritis, [Rheumatoid Arthritis (“RA”)], and Scleroderma. Of

these, Cogan’s and Susac’s has been largely ruled out by a normal [ophthalmic]

exam although her inner ear MRI was not definitive . . . in ruling out Cogan’s.

Wegeners is unlikely due to her negative [antineutrophil cytoplasmic antibodies],

and RA is also unlikely. UC is unlikely due to lack of [gastrointestinal]

symptoms. AS and Scleroderma are very rare. Relapsing Polychondritis remains

a possibility, but it is difficult to rule out.

Regarding this picture arising post-vaccination (MMR), I have never

encountered this situation although I have seen about 300 patients with bilateral

loss in my career. It cannot be common.

Id. at 792-93. Dr. Hain suggested another ophthalmology evaluation to “be sure about Cogan’s.”

Id. at 793. Dr. Hain referred Petitioner to neurotologist Akihiro Matsuoka, M.D., who Dr. Hain

said had more experience with AIED than anyone he knew in the Chicago area. Id. at 794.

On December 2, 2019, Petitioner saw neurotologist Dr. Matsuoka at NM, for a second

opinion on AIED. Pet. Ex. 2 at 757-59. Dr. Matsuoka’s assessment was steroid-dependent

AIED, and he ordered additional work-up. Id. at 759. In his assessment, Dr. Matsuoka observed

Cogan’s and Susac’s syndromes had “notably” been “ruled out.” Id.

On December 9, 16, and 23, 2019, Petitioner was seen by Dr. Matsuoka and received

transtympanic steroid injections. Pet. Ex. 2 at 718, 739, 693.

On December 31, 2019, Petitioner was evaluated by rheumatologist Anisha Dua, M.D., at

NM, for SNHL and problems with balance and vision. Pet. Ex. 2 at 664. Dr. Dua opined that

Petitioner’s “clinical presentation and steroid responsiveness [were] consistent with AIED.” Id.

She opined the work-up showed no evidence of systemic autoimmune disease, and believed the

10

treatment needed to be more aggressive, including an increased dose of methotrexate and

Rituxan. 24 Id.

On January 3 and 17, 2020, Petitioner received additional transtympanic steroid

injections, administered by Dr. Matsuoka. Pet. Ex. 2 at 601, 628.

On February 26, 2020, Petitioner followed up with Dr. Dua after receiving two Rituxan

infusions that month. Pet. Ex. 2 at 483-87. Petitioner reported that her balance was possibly a

little bit better, and her hearing loss fluctuated with no major improvement or worsening. Id.

On March 13, 2020, Petitioner followed up with Dr. Matsuoka regarding her AIED. Pet.

Ex. 2 at 464. Dr. Matsuoka noted that an audiogram was unchanged since Petitioner’s last test.

Id. His assessment was AIED Type I with stable condition. Id.

The records filed show that Petitioner continued to follow up with Dr. Matsuoka for

treatment through 2021. See Pet. Ex. 2 at 74-308. She had tympanostomy tubes placed in her

right ear in July 2020 and left ear in November 2020. Id. at 197, 308. In December 2020 and

January 2021, Petitioner received additional transtympanic steroid injections. Id. at 125, 146,

156, 173. She remained on Rituxan and methotrexate for treatment of AIED. Id. at 94-103. An

audiogram on March 1, 2021 showed moderate to severe bilateral SNHL. Id. at 84.

On June 5, 2023, Petitioner underwent right cochlear implant 25 surgery. See Pet. Ex. 51

at 394-95. The following year, in June 2024, Petitioner underwent left cochlea implant surgery.

Pet. Mot. at 31.

2. Petitioner’s Declaration 26

At the time of vaccination, Petitioner was working as an operating room nurse at NM

Central DuPage Hospital. Pet. Ex. 6 at ¶ 1. An annual health screening done by her employer in

2019 found Petitioner had a negative mumps titer. Id. Petitioner’s employer then required her to

24

Rituxan, known generically as rituximab, is a “B cell-targeting [biologic agent] for the

treatment of immune-mediated diseases.” Pet. Ex. 35 at 1 (Celine Kaegi et al., Systematic

Review of Safety and Efficacy of Rituximab in Treating Immune-Mediated Disorders, 10

Frontiers Immunol. 1990 (2019)).

25

Cochlear Implant is a “a device consisting of a microphone, signal processor, external

transmitter, and implanted receiver; the receiver is surgically implanted under the skin near the

mastoid process above and behind the ear.” Cochlear Implant, Dorland’s Med. Dictionary

Online, https://www.dorlandsonline.com/dorland/definition?id=82067 (last visited Dec. 16,

2025).

26

Although titled an affidavit, it was not notarized. Therefore, it is referenced as a declaration.

Petitioner also submitted a declaration stating no prior civil action had been filed for her alleged

vaccine injury. See Pet. Ex. 7.

11

be vaccinated to protect against mumps. Id. She received the first dose of the MMR vaccine on

March 15, 2019, and her second dose on April 19, 2019. Id.

Petitioner averred that her hearing loss occurred 32 days after receiving the second dose

of the MMR vaccine. Pet. Ex. 6 at ¶ 3. In May 2019, Petitioner and her husband traveled to

Hawaii. Id. at ¶ 1. At the end of her trip, Petitioner noticed that her hearing was “muffled.” Id.

On May 25, 2019, three days after she returned home from Hawaii, Petitioner visited an urgent

care “to see if there was an obvious and fixable problem.” Id. At this visit, Petitioner’s problem

of “what felt like blocked ears” was “misdiagnosed” as fluid in the ears, and Petitioner was told

by the nurse practitioner “it would go away.” Id. at ¶ 3. “Over the following two and a half

weeks, [her] hearing loss, balance[,] and visual symptoms became more prominent and

debilitating.” Id. at ¶ 2. Petitioner explained that she began “using a wooden staff to walk,” she

could no longer navigate poorly lit spaces, and she had difficult driving. Id.

Petitioner consulted with Dr. Patel, an ENT surgeon that she worked with as an OR

nurse, regarding “how long [she] should wait for [her] ears to clear.” Pet. Ex. 6 at ¶ 4. Dr. Patel

offered to examine Petitioner. Id. On June 4, 2019, Petitioner went to Dr. Patel’s office. Id. Dr.

Patel found no fluid in Petitioner’s ears and had an audiologist run an audiogram. Id. The

audiogram showed significant bilateral, symmetrical SNHL. Id. “When Dr. Patel saw the

audiogram her response was essentially ‘how have you been able to hide this much hearing loss

at work?’” Id. Dr. Patel discussed next steps with Petitioner. Id. Petitioner made an

appointment the next morning, June 5, with a neuro-ophthalmologist. Id. The balance of

Petitioner’s declaration recounted her clinic course and her visits with various specialist as

documented in her medical records. Pet. Ex. 6 at ¶¶ 4-11.

Petitioner’s declaration also addressed the impact of her injury on her ability to work and

her quality of life. Due to her injury, Petitioner “had to leave a job that [she] loved and excelled

at.” Pet. Ex. 6 at ¶ 14. Petitioner was unable work in the OR due to her balance, hearing, and

visual symptoms. Id. at ¶ 6. Since leaving work, Petitioner is “longer able to plan for [an] active

retirement.” Id. at ¶ 14.

Petitioner averred that prior to her hearing loss, she was “a healthy and active adult.” Pet.

Ex. 6 at ¶ 1. As of the February 1, 2022 declaration, Petitioner relies on a “staff” when walking

around and continues to have difficulties driving. Id. at ¶ 12. She is unstable is “low light

surroundings” and unable “take a walk and casually look around because [she] lose[s] [her]

balance if [she] do[es] not concentrate.” Id. “Walking on uneven surfaces requires a great deal

of effort” and “[g]oing up or down stairs or escalators is frightening.” Id. Petitioner cannot hear

in noisy settings, even with her hearing aids in. Id. at ¶ 13. She is “no longer able to hear music

clearly; concerts and movies no longer are enjoyable.” Id. And she has difficulties

communicating with her family. Id. She concluded that it “has been stunning to go from being a

busy healthy person . . . to dealing with this much change and loss.” Id. at ¶ 16.

12

D. Expert Reports 27

1. Petitioner’s Expert, Edwin M. Monsell, M.D., Ph.D. 28

a. Background and Qualifications

Dr. Monsell is “board-certified by the American Board of Otolaryngology—Head and

Neck Surgery and hold[s] a Certificate of Added Qualifications from the same board in

Neurotology (diseases and surgery of the inner ear and related skull base).” Pet. Ex. 11 at 1; see

also Pet. Ex. 12 at 4. He obtained a Ph.D. in cell biology and neuroscience from Duke

University in 1977 and an M.D. from University of North Carolina School of Medicine in 1979.

Pet. Ex. 12 at 1. He then completed a surgical internship and a residency in the Otolaryngology-

Head and Neck Surgery department at Northwestern University, followed by a fellowship at the

House Ear Institute in Los Angeles, CA. Id. Since 1986, Dr. Monsell has held various hospital

or other professional appointments and since 2000, he has also held faculty appointments. Id. at

1-2. He currently holds two hospital appointments in Seattle, Washington and teaches in the

Otolaryngology-Head and Neck Surgery department at University of Washington in Seattle. Id.

He is a member and has held various positions for the American Academy of Otolaryngology-

Head and Neck Surgery, Association for Research in Otolaryngology, and other professional

societies. Id. at 2-3; Pet. Ex. 11 at 1. In 2003, Dr. Monsell “received the Harris P. Mosher

Award, the highest award for clinical and translational research in Otolaryngology by the

American Laryngological, Rhinological[,] and Otological Society (a/k/a the Triological Society)

for [his] research on mechanisms of hearing loss.” Pet. Ex. 11 at 1. Throughout his career, he

has published on the mechanisms of hearing loss, “treated many thousands of patients with

hearing loss[,] and performed over 3,500 major ear operations to remove tumors or infections

and restore hearing.” Id.; see also Pet. Ex. 12 at 10-18.

b. Opinion

Dr. Monsell opined that Petitioner suffered from AIED, a form of “fluctuating or rapidly

progressing sensorineural hearing loss that is responsive to immunosuppressive therapy.” Pet.

Ex. 11 at 13. Dr. Monsell opined that “more likely than not” Petitioner’s “MMR vaccination had

a substantial causal role in the development of her AIED.” Id. at 18.

i. Althen Prong One

Dr. Monsell’s causal theory focused on MMR vaccination as a live attenuated virus

vaccination. Pet. Ex. 11 at 14. Dr. Monsell proposed that live components of the MMR vaccine

can stimulate the immune system and lead to a vaccine-induced autoimmune response. Id. at 15.

He posited that the “many associations between the naturally occurring viruses, the attenuated

27

Although the undersigned has reviewed all of the expert reports and medical literature, for the

sake of brevity this Ruling does not include all details of the experts’ opinions. Instead, the

undersigned focuses on the experts’ material opinions, as they relate to the relevant issues.

28

Dr. Monsell submitted one expert report. Pet. Ex. 11.

13

viruses in the MMR vaccine, and hearing loss” explain “how the attenuated live viruses in the

MMR vaccine are likely responsible for developing autoimmune hearing loss and vestibular

disease in [Petitioner].” Id.

In support of his opinion, Dr. Monsell cited a publication from the U.S. Department of

Health and Human Services explaining that live attenuated virus vaccines “use a weakened (or

attenuated) form of the germ that causes a disease.” Pet. Ex. 31 at 2. 29 Live virus vaccines

include both measles and mumps. Id. at 3. Dr. Monsell explained that live attenuated viruses are

genetically altered to be less virulent than the live wild-type virus. Pet. Ex. 11 at 14. While less

virulent, “[a] live virus vaccine must infect cells in the recipient to stimulate an immune

response.” Id. He opined that evidence that measles, mumps, and/or rubella infections cause

hearing loss “suggests that live attenuated virus vaccination can cause hearing loss, at least in

rare instances.” Id.

Dr. Monsell noted there is “significant medical literature” discussing an increased

incidence of hearing loss after mumps and measles infections. Pet. Ex. 11 at 14; see, e.g., Pet.

Ex. 30 at 1 (describing profound hearing loss after mumps); 30 Pet. Ex. 40 at 1 (acknowledging “a

well established association between viral infection and sensorineural hearing loss” including

infections with measles and mumps); 31 Pet. Ex. 43 at 1 (describing measles-included hearing loss

in children); 32 Pet. Ex. 49 at 1 (noting mumps induced hearing loss “is not rare”). 33

For example, the study by Olajuyin et al. followed 112 children with measles-induced

hearing loss. Pet. Ex. 43 at 2. Seventy-two of these children had profound bilateral SNHL. Id.

at 3. In McKenna, the author explained measles infections accounted for five to 10 percent of all

cases of profound bilateral SNHL prior to the advent of vaccination. Pet. Ex. 40 at 3. McKenna

also noted that in “some individuals the attenuated [measles] virus [in vaccines] is pathogenic. . .

. Cases of unilateral and bilateral profound sudden deafness have been reported with the

administration of the vaccine.” Id. Further, the article noted that infection following the mumps

29

Vaccine Types, U.S. Dep’t Health & Hum. Servs., https://www.hhs.gov/immunization/basics/

types/index.html (last accessed June 21, 2023).

30

R. Hall & H. Richards, Hearing Loss Due to Mumps, 62 Arch. Dis. Child. 189 (1987). This

article was also filed as Resp. Ex. C, Tab 12.

31

Michael J. McKenna, Measles, Mumps, and Sensorineural Hearing Loss, 830 Ann. NY Acad.

Sci. 291 (1997). This article was also filed as Resp. Ex. C, Tab 6.

32

Oyebanji A. Olajuyin et al., Measles-Induced Hearing Loss: Pattern, Diagnosis, and

Prevention Among Children in Ekitis State, Southwest Nigeria, 23 Saudi J. Otorhinolaryngol.

Head & Neck Surg. 65 (2021).

33

Martti Vuori et al., Perceptive Deafness in Connection with Mumps: A Study of 298

Servicemen Suffering from Mumps, 55 Acta Otolaryngol. 231 (1962). This article was also filed

as Resp. Ex. C, Tab 8.

14

vaccination “is known to occur, and complications . . . including sudden unilateral and bilateral

hearing loss has been reported.” Id. at 5.

The study from Hall and Richards examined 33 children with unilateral SNHL hearing

loss and concluded “mumps could be a considered a cause in a third of the cases of hearing loss

studied.” Pet. Ex. 30 at 2-3. The authors explained hearing loss as a complication of mumps

infection is “characteristically unilateral and sensorineural in nature, and is thought to result from

endolymphatic labyrinthitis.” 34 Id. at 2. The authors also reported that “permanent hearing loss

can result from subclinical or unrecognized infections.” Id. at 4.

Next, Dr. Monsell discussed the pathogenesis of virus-induced SNHL. Pet. Ex. 11 at 15-

16. Relying on Cohen et al., 35 Dr. Monsell first explained that the mechanism of SNHL in

mumps included “atrophy of hair cells in the organ of Corti[36] and stria vascularis,[37] and

damage to the myelin sheath around the vestibulocochlear nerve.” 38 Id. at 15 (quoting Pet. Ex.

23 at 11); see also Pet. Ex. 40 (discussing mechanisms of SNHL). Dr. Monsell opined that

rubella, measles, and mumps virus infections produce a similar pathology. Pet. Ex. 11 at 15

(citing Pet. Ex. 24). 39 The viruses “are believed to infiltrate the stria vascularis of the cochlea

34

Endolymphatic labyrinthitis is “inflammation of the membranous labyrinth of the inner ear.”

Resp. Ex. C at 6; see also supra note 17.

35

Brandon E. Cohen et al., Viral Causes of Hearing Loss: A Review for Hearing Health

Professionals, 18 Trends Hear. 1 (2014). This article was also filed as Resp. Ex. C, Tab 5.

36

Organ of Corti is “the organ, resting on the basilar membrane of the cochlear duct, that

contains the auditory hair cells, special sensory receptors for hearing, as well as several types of

supporting cells.” Organum Spirale, Dorland’s Med. Dictionary Online, https://www.dorlands

online.com/dorland/definition?id=94965 (last visited Dec. 18, 2025).

37

Sria Vascularis is “a layer of vascular tissue consisting of epithelial cells, mesothelial cells,

and probably some neuroectoderm; it covers the outer wall of the cochlear duct and is thought to

secrete the endolymph.” Sria Vascularis Ductus Cochlearis, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=108900 (last visited Dec. 18, 2025).

38

Vestibulocochlear nerve is the “eighth cranial nerve; it . . . is connected with the brain by

corresponding roots, the vestibular and the cochlear roots.” Nervus Vestibulocochlearis,

Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/dorland/

definition?id=92439 (last visited Dec. 18, 2025).

39

A.D. Dunmade et al, Profound Bilateral Sensorineural Hearing Loss in Nigerian Children: Any

Shift in Etiology?, 12 J. Deaf Stud. Deaf Educ. 112 (2007).

15

during the viremic stage, and from there they either enter the endolymph[40] directly or damage

the metabolic functions of the stria vascularis in some way.” Pet. Ex. 24 at 6.

In Cohen et al., the authors noted the mechanisms involved in viral-induced SNHL “vary

greatly, ranging from direct damage to inner ear structures, including inner ear hair cells and

organ of Corti (as seen in some of the classically described causes of viral hearing loss such as

measles), to induction of host immune-mediated damage.” Pet. Ex. 23 at 1. The authors

specified that rubella- and mumps-induced SNHL was associated with direct damage to the inner

ear structures. Id. at 2 tbl.2. Measles-induced SNHL was associated with both direct damage as

well as an indirect etiology of “[d]ecreased immunity and secondary infection.” Id. The authors

furthered explained temporal bone studies of patients with measles-induced SNHL have “shown

degeneration of cochlear neurons most prominently in the basal turn, degeneration of the organ

of Corti and stria vascularis, and cellular infiltration of the cochlea.” Id. at 9. Of note, in their

discussion of measles-induced SNHL, Cohen et al. stated MMR vaccination was “rarely

associated with SNHL, with a time course of onset corresponding to incubation period of

measles infection and an incidence of [one] case per [six] to [eight] million vaccine doses.” Id.

The article from McKenna examined the histopathology of the temporal bones in patients

with measles- or mumps-induced SNHL. Pet. Ex. 40 at 3. The author noted “destruction or

degeneration of the organ of Corti, stria, and cochlear neurons is typical.” Id. “Of particular

significance is the presence of fibrous tissue in the scala of the basal turns, which is suggestive of

an associated inflammatory process (Fig. 1).” Id.

FIGURE 1. Case of profound bilateral hearing loss at

age four in association with measles. . . Pathologic

changes are similar in both ears. Predominant

histopathologic features include atrophy of the organ of

40

Endolymph is “the fluid contained in the membranous labyrinth of the ear; it is entirely

separate from the perilymph.” Endolympha, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=16333(last visited Dec. 18, 2025).

16

Corti and stria vascularis with degeneration of cochlear

neurons.

Id. at 4 fig. 1.

Moreover, Dr. Monsell explained infiltration of the inner ear with acute and chronic

inflammatory cells is a characteristic finding in animal models of experimental viral inner

infection. Pet. Ex. 11 at 16 (citing Pet. Ex. 41). 41 In Merchant et al., the authors opined that

evidence of a viral cause for sudden deafness is based on onset occurring in association with an

upper respiratory infection, positive serology studies supporting a systemic viral infection, and

histopathological findings similar to those seen after hearing loss associated with mumps or

rubella infections. Pet. Ex. 41 at 8. Dr. Monsell described an animal study by Fukuda et al. 42

that studied acute measles infection of the cochlea. Pet. Ex. 11 at 16 (citing Pet. Ex. 27).

“Positive immunofluorescence [indicating the presence of viral antigens] was observed in the

inflammatory cell infiltrates in the cochlear ducts and the lining of the perilymphatic structure.”

Id. (citing Pet. Ex. 27 at 2). The findings were consistent with endolymphatic labyrinthitis and

were consistent with prior studies of human temporal bone pathology caused by measles. Pet.

Ex. 27 at 1.

In humans, MRIs have shown signs of protein infiltrations of the inner ear during viral

infections. Pet. Ex. 11 at 16. In support, Dr. Monsell cited to an article by Otake et al. 43 who

reported on a case of profound unilateral SNHL following a case of subclinical mumps. Id.

(citing Pet. Ex. 45). A 3D-FLAIR MRI revealed an abnormal signal of the right cochlea and

vestibule indicating “hemorrhage or a high concentration of protein in the right ear” consistent

with labyrinthitis associated with “mumps deafness.” Pet. Ex. 45 at 1. Dr. Monsell explained

the MRI findings were due to an “intense local inflammatory reaction.” Pet. Ex. 11 at 16.

Another study, by Westmore et al., 44 found mumps virus in a perilymph sample (extracellular

fluid from the inner ear) collected five days after the onset of deafness. Id. (citing Pet. Ex. 50 at

1-2).

Next, Dr. Monsell opined that “the inner ear actively participates in inflammatory

processes.” Pet. Ex. 11 at 16. Dr. Monsell explained that “the inner ear is not an

immunologically privileged organ.” Id. Further, the inner ear is affected by systemic

41

Saumil N. Merchant et al., Pathology and Pathophysiology of Idiopathic Sudden Sensorineural

Hearing Loss, 26 Otol. Neurotol. 151 (2005).

42

Saroshi Fukuda et al., Acute Measles Infection in the Hamster Cochlea, 514 Acta Otolaryngol.

111 (1994).

43

Hironai Otake et al., 3D-FLAIR Magnetic Resonance Imaging in the Evaluation of Mumps

Deafness, 70 Int’l J. Pediatr. Otorhinolaryngol. 2115 (2006).

44

G.A. Westmore et al., Isolation of Mumps Virus from the Inner Ear After Sudden Deafness, 1

Brit. Med. J. 14 (1979). This article was also filed as Resp. Ex. C, Tab 9.

17

inflammatory events. Id. Dr. Monsell described an experiment by Adams et al. 45 where the

authors induced injury within mouse cochlea by injecting liposaccharides to induce systemic

inflammation. Id. (citing Pet. Ex. 13). Dr. Monsell explained “the inner ear responded by

transcribing and releasing [tumor necrosis factor], an important cytokine that promotes

inflammation.” Id. Additional medical literature explained it is “well accepted that the inner ear

is fully capable of generating an immune response and that this immune response can be

destructive to the delicate inner ear.” Pet. Ex. 29 at 3-4. 46

Dr. Monsell noted other ear diseases demonstrate autoimmunity in the inner ear. Pet. Ex.

11 at 14. Dr. Monsell explained that otosyphilis is clinically similar to AIED. Id.; see also Pet.

Ex. 29 at 6 (noting otosyphilis should be excluded by serum analysis prior to an AIED

diagnosis). Dr. Monsell explained otosyphilis has a disease mechanism that is “at least partly

inflammatory and thereby demonstrates the potential for infection to cause autoimmunity in the

inner ear.” Pet. Ex. 11 at 14.

Dr. Monsell opined that viruses “are common causes of autoimmune disease in general.”

Pet. Ex. 11 at 15. Further, Dr. Monsell noted that MMR vaccine induction of autoimmune

disease has been reported in other disease contexts with “autoimmune thrombocytopenia is the

most established of all vaccine‐related autoimmune disorders.” Id. at 17.

Turning to vaccination-induced hearing loss, Dr. Monsell relied on Agmon-Levin et al. 47

to explain the “proposed mechanism by which infectious agents, including live attenuated viral

vaccines, may induce autoimmunity.” Pet. Ex. 11 at 16 (citing Pet. Ex. 14). Agmon-Levin et al.

stated that “[i]nfectious agents are considered to be the most common triggers of autoimmunity,

and vaccines that contain antigens from infectious agents might induced autoimmunity by similar

mechanisms such as molecular mimicry, bystander activation, epitope spreading, and polyclonal

activation.” 48 Pet. Ex. 14 at 2. Dr. Monsell opined the mechanisms discussed in Agmon-Levin

et al. “are complex microbiological processes that could be subject to functionally different

genetic variants in vaccine recipients and idiosyncratic reactions leading to vaccine caused

AIED.” Pet. Ex. 11 at 16-17.

Additionally, Dr. Monsell opined medical literature supported an association between

MMR vaccination and hearing loss. Pet. Ex. 11 at 14. Dr. Monsell emphasized that the 2012

45

J.C. Adams et al., Selective Activation of Nuclear Factor Kappa B in the Cochlea by Sensory

and Inflammatory Stress, 160 Neuroscience 530 (2009).

46

Quinton Gopen & Jeffery P. Harris, Autoimmune Inner Ear Disease, in Head and Neck

Manifestations of Systemic Disease 53 (Jeffery P. Harris & Michael H. Weisman eds., 2007).

For a detailed description of the “basic steps” of the inner ear immune response, see Pet. Ex. 29

at 4.

47

Nancy Agmon-Levin et al., Vaccines and Autoimmunity, 5 Nat’l Rev. Rheumatol. 648 (2009).

48

These mechanisms are defined by Agmon-Levin et al. See Pet. Ex. 14 at 3 Box 2.

18

Institute of Medicine (“IOM”) committee 49 found an association between measles and mumps

vaccination and hearing loss, stating they “assesse[d] the mechanistic evidence regarding an

association between measles or mumps vaccine and hearing loss as low-intermediate[50] based on

knowledge about the natural infection, experimental evidence, and eight cases.” Id. at 15 (citing

Pet. Ex. 48 at 119). The eight cases 51 presented “clinical and experimental evidence suggestive

but not sufficient for the committee to conclude” that the MMR vaccine was a “contributing case

of hearing loss.” Pet. Ex. 48 at 119.

Dr. Monsell cited a review conducted by Asatryan et al., 52 which estimated hearing loss

after MMR vaccination occurred in one per six to eight million doses. Pet. Ex. 11 at 14 (citing

Pet. Ex. 16). Asatryan et al. conducted a review of VAERS 53 data and identified 44 cases of

“likely idiopathic” SNHL after MMR vaccination. Pet. Ex. 16 at 2. They also researched for

published case reports of SNHL and identified 11 cases following MMR vaccination. Id. at 2.

The authors noted the onset of hearing loss in the majority of these cases “was consistent with

the incubation periods of wild measles and mumps viruses.” Id. Asatryan et al. posited that as

49

Inst. of Med., Adverse Events Associated with Childhood Vaccines: Evidence and Causality

(Kathleen Stratton et al. eds., 2012). This was also filed as Resp. Ex. C, Tab 15.

50

The IOM committee developed four categories for mechanistic weight of the evidence

assessments: strong, intermediate, weak, and lacking. Inst. of Med., Adverse Events Associated

with Childhood Vaccines: Evidence and Causality 12-14 (Kathleen Stratton et al. eds., 2012)

[hereinafter 2012 IOM report]. An intermediate assessment is based on a “least two cases, taken

together, for which the committee concludes the vaccine may be a contributing cause of the

adverse event, based on an overall assessment of attribution in the available cases and clinical,

diagnostic, or experimental evidence consistent with relevant biological response to [the]

vaccine.” Id. at 14. Low-intermediate assessment is based on “at least two cases, that, taken

together, while suggestive, are nonetheless insufficient to conclude that the vaccine may be a

contributing case of the adverse event.” Id. Although the parties only filed Chapter 4 of the

2012 IOM report, the undersigned is familiar with the entirety of the 2012 IOM report. See Pet.

Ex. 48; Resp. Ex. C, Tab 15.

51

The eight cases include some cited by Dr. Monsell. For a full discussion of the cases

considered by the IOM, see Pet. Ex. 48 at 117-18.

52

Armenak Asatryan et al., Live Attenuated Measles and Mumps Viral Strain‐Containing

Vaccines and Hearing Loss: Vaccine Adverse Event Reporting System (VAERS), United States,

1990-2003, 26 Vaccine 1166 (2008).

53

VAERS, the Vaccine Adverse Event Reporting System, is “a national early warning system to

detect possible safety problems in U.S.-licensed vaccines. . . . VAERS is a passive reporting

system . . . [and] is not designed to determine if a vaccine caused a health problem, but is

especially useful for detecting unusual or unexpected patterns of adverse event reporting that

might indicate a possible safety problem with a vaccine.” About VAERS, U.S. Dep’t Health &

Hum. Servs., https://vaers.hhs.gov/about.html (last visited Dec. 16, 2025).

19

“vaccines against measles and mumps contain live attenuated viral strains, it is biologically

plausible” that individuals could develop hearing loss as a complication of MMR vaccination.

Id. at 1.

Of note, in the 14 cases described by Asatryan et al., many of the patients who reported

bilateral hearing loss after vaccination did not describe a history of fever or illness symptoms

prior to hearing loss. Pet. Ex. 16 at 3-5 (see Cases 1, 2, 9, 10, 11, 12, and 13).

Finally, Dr. Monsell provided several case reports of SNHL following vaccination for

measles, mumps, and/or rubella. 54 Pet. Ex. 11 at 15. In Hulbert et al., 55 the authors reported a

case of bilateral SNHL following a live measles-rubella vaccination. Pet. Ex. 32 at 1. The

patient, a 27-year-old woman, experienced hearing loss 22 days after receiving a live measles-

rubella vaccination. Id. Audiography taken 29 days after vaccination showed profound bilateral

SNHL. Id. She had generalized arthralgias three days after vaccination and developed a fever,

tinnitus, dizziness, vomiting, and gait unsteadiness shortly thereafter. Id. Serological tests for

syphilis, systemic lupus, Epstein-Barr virus, St. Louis encephalitis virus, and western equine and

eastern equine encephalomyelitis viruses were negative. Id. The patient had Immunoglobulin

(“Ig”) M antibodies for rubella. Id. The authors noted permanent bilateral hearing loss is “a

known but uncommon complication of measles, mumps, and rubella infections.” Id. “Severe

hearing loss has been reported as a complication of the mumps vaccine and of the measles-

mumps-rubella trivalent vaccine in children, usually in association with encephalitis.” Id.

Hulbert et al. concluded that “the patient’s symptoms and their temporal sequence after

vaccination, coupled with suspicious audiographic findings and serologic evidence of an acute

rubella infection, offer compelling evidence that her deafness was a complication of

vaccination.” Id.

Additional case reports described children with SNHL following measles, mumps, and/or

rubella vaccinations. A 1985 report from Brodsky and Stanievich 56 reported a case of a three-

year-old-child who developed a “encephalitis-like reaction” 10 days after receiving an MMR

vaccine. Pet. Ex. 21 at 2. Soon after, the child’s parents became concerned about hearing loss,

and the child was ultimately diagnosed with “severe to profound bilateral [SNHL].” Id. The

authors noted that the child’s hearing loss was “similar to the loss typically seen after infectious

54

In addition to the below discussed case reports, Dr. Monsell provided a case report from Koga

et al. that purported to report “a case of bilateral acute profound deafness most likely due to

MMR vaccination.” Pet. Ex. 38 at 1 (Keijiro Koga et al., Bilateral Acute Profound Deafness

After MMR Vaccination ‐ Report of a Case, 94 Nihon Jibiinkoka Gakkai Kaiho 1142 (1991)).

However, while a short abstract of the Koga et al. article is written in English, the case report is

written in Japanese.

55

Tim V. Hulbert et al., Bilateral Hearing Loss After Measles and Rubella Vaccination in an

Adult, 325 NEJM 134 (1991).

56

Lisa Brodsky & John Stanievich, Sensorineural Hearing Loss Following Live Measles Virus

Vaccination, 10 Int’l J. Pediatr. Otorhinolaryngol. 159 (1985).

20

measles.” Id. at 4. A 1995 case report from Jayarajan and Sedler 57 described the development of

unilateral SNHL in a 15-month-old child. Pet. Ex. 34 at 1. Twenty-four hours after measles

vaccination, she became unwell and began to stagger while walking, and two weeks later she

was admitted to the hospital with ataxia, drowsiness, and general irritability. Id. The child was

found to have profound left-sided hearing loss during routine screening when she was five years

old. Id. The authors noted measles infections account for five to 10 percent of SNHL in children

and noted incidence of neurological sequala following measles vaccination was one per 1.6

million doses of the vaccine. Id. Jayarajan and Sedler concluded the “sequence of events

suggests that a labyrinthitis which developed after measles vaccination may have resulted in

unilateral left sided hearing loss.” Id. at 1-2.

Stewart and Prabhu 58 reported nine cases of SNHL in children following MMR

vaccination. Pet. Ex. 47 at 1. In three cases, the deafness was found to be unrelated to the MMR

vaccine. Id. In six cases, the cause was unknown, but MMR vaccination remained a possible

etiology. Id. The authors concluded “[a]ny risk of deafness after MMR [immunization] is small

and must be weighed against the risks of the natural diseases.” Id. at 2.

A more recent case report, published in 2018, from Rikitake et al. 59 in Japan, reported

onset of bilateral hearing loss in a five-year old girl 18 days after receiving a mumps vaccine and

a measles-rubella vaccine. Pet. Ex. 46 at 2. Twelve days after vaccination the child had a fever

for one day, and vomited once the following day, before her symptoms remitted. Id. Eighteen

days after vaccination, the child was noted to have poor hearing and was brought to the hospital.

Id. She was examined by otorhinolaryngology and diagnosed with “bilateral acute [SNHL]

associated with a side reaction of the vaccination.” Id. The authors explained there was no other

finding or symptom to induce disease in this patient and concluded that SNHL about three weeks

after vaccination suggests the hearing loss was caused by vaccination. Id. at 3. Further, they

noted that unlike other case reports of SNHL, the child did not have encephalitis. Id. Rikitake et

al. explained the mumps vaccine is a live vaccine and noted that since the blood inner ear barrier

is immature in infants, “hearing loss may be easily caused by mumps virus.” Id. The authors

reported that incidence of hearing loss following natural mumps infection were 1/1,000-20,000

and the risk of hearing loss following mumps vaccination was reported to be about 1/6-8 million.

Id.

57

V. Jayarajan & P.A. Sedler, Hearing Loss Following Measles Vaccination, 30 J. Infect. 184

(1995).

58

Barbara J.A. Stewart & P. Umesh Prabhu, Reports of Sensorineural Deafness After Measles,

Mumps, and Rubella Immunization, 69 Arch. Dis. Child. 153 (1993).

59

Masahiro Rikitake et al., Bilateral Deafness as a Complication of the Vaccination - A Case

Report, 22 Int’l Tinnitus J. 19 (2018).

21

ii. Althen Prong Two

Dr. Monsell concluded that “more likely than not,” Petitioner’s MMR vaccination had a

“substantial causal role” in her development of AIED. Pet. Ex. 11 at 18. He opined that but for

this vaccination, Petitioner would not have developed AIED. Id.

Dr. Monsell opined that the evidence that Petitioner suffered an MMR vaccine injury was

“compelling.” Pet. Ex. 11 at 17. He summarized his opinion as follows.

First, as discussed above, there is an association between the MMR vaccine, clinical

measles, mumps, and rubella, and hearing loss. Pet. Ex. 11 at 17. Second, Petitioner was

“serologically negative, and thus immunologically naïve to mump antigens” when she received

the MMR vaccine. Id. Third, Dr. Monsell noted that the MMR vaccine “is not often

administered to adults, who may not have as a robust immune system as children.” Id. Next, Dr.

Monsell explained the MMR vaccine received by Petitioner contains three different live

attenuated viruses plus an adjuvant. Id.: see also Pet. Ex. 52 (vaccine package insert). 60 Dr.

Monsell explained that, theoretically, a vaccine with “more varied array of antigens,” was more

likely “to trigger an immune response that might eventually turn into autoimmune disease.” Id.

(quoting Pet. Ex. 14 at 2). Fifth, he noted that MMR vaccine induction of autoimmune disease

had been reported for other diseases such as autoimmune thrombocythemia. Id. Finally, Dr.

Monsell noted that Petitioner’s treating physicians agreed she suffered from AIED, an

autoimmune disease, with “no other autoimmune disease that her AIED could be secondary to.”

Id.

Additionally, Dr. Monsell opined that Petitioner’s clinical course was consistent with

AIED. Pet. Ex. 11 at 13-14. Dr. Monsell emphasized that Petitioner’s AIED was not associated

with any another autoimmune condition such as psoriasis, idiopathic thrombocytopenic purpura,

rheumatoid arthritis, primary biliary sclerosis, inflammatory bowel disease, connective tissue

diseases, or systemic autoimmune disease. Id. at 13, 17.

Moreover, Dr. Monsell ruled out several causes of SNHL such as age-related hearing

loss, toxic noise exposure, ototoxicity, Meniere’s disease, vestibular schwannoma, and stroke.

Pet. Ex. 11 at 12-13. He also ruled out eustachian tube dysfunction as a cause of Petitioner’s

hearing loss. Id. at 12. While eustachian tube dysfunction is associated with plane travel,

Petitioner’s clinical course was not consistent with eustachian tube dysfunction, and eustachian

tube dysfunction is not associated with SNHL. Id.

iii. Althen Prong Three

Dr. Monsell placed the onset of Petitioner’s symptoms associated with AIED as

approximately 30 days after receiving the second dose of her MMR vaccine. Pet. Ex. 11 at 17.

He opined Petitioner’s onset was “consistent with an immune‐mediated response following

60

Of note, the vaccine package insert identifies “[n]erve deafness” as an adverse reaction. Pet.

Ex. 52 at 4.

22

MMR vaccination.” Id. at 18. He further opined Petitioner’s onset was “within the timeframe

that [is] medically acceptable for autoimmune events following an antigenic trigger.” Id. at 17.

In support of this timeframe, Dr. Monsell noted that MMR vaccination has been

associated with autoimmune disease and explained that the autoimmune complication of

thrombocytopenia is included on the package insert for MMR vaccination. Pet. Ex. 11 at 17. Dr.

Monsell noted that package insert described “this autoimmune event following MMR

vaccination as occurring within [four to six] weeks after MMR vaccination.” Id.

In the summary of case reports of hearing loss after MMR vaccination from VAERS data

reviewed by Asatryan et al., onset (when reported) “ranged from [two] to 89 days following

vaccination, with a peak on days 10 through 14.” Pet. Ex. 16 at 3, 3 fig.1. Of the cases studied,

Asatryan et al. summarized 14 with detailed clinical data available. Id. at 3-5. In Case 1, onset

of hearing loss was noted the month after vaccination; in Case 6, hearing loss occurred within

one month (but “possibly” earlier); in Case 8, ataxia was noted one month after vaccination

followed by hearing loss four months after vaccination; in Case 9, hearing loss was noted two

months after vaccination; and in Case 13, tinnitus and hearing loss occurred one month after

vaccination. Id. at 3-5. Finally, in Case 14, the patient had her first MMR vaccination in August

2003 and the second vaccine in September 2003. Id. at 5. Two weeks following the second

vaccination she developed headaches, vertigo, and tinnitus, and a subsequent audiologic

evaluation in October showed bilateral hearing loss. Id.

2. Respondent’s Expert, Herman Staats, Ph.D. 61

a. Background and Qualifications

Dr. Staats obtained his B.S. in medical technology from Salisbury University in

Salisbury, Maryland and a Ph.D. in basic medical sciences (microbiology and immunology) from

the University of South Alabama in Mobile, Alabama. Resp. Ex. B at 1. He is a professor in the

Department of Pathology at Duke University School of Medicine and holds joint appointments

as an associate professor of immunology and associate professor of medicine. Id.; Resp. Ex. A at

1. He is also a member of the Duke Human Vaccine Institute. Resp. Ex. A at 1. Throughout his

career, Dr. Staats has been a member of and/or held positions with various organizations and

professional societies. Resp. Ex. B at 3-4. Dr. Staats “perform[s] research on the discovery and

evaluation of vaccine adjuvants.” Resp. Ex. A at 1. His bibliography consists of over 200

publications. Resp. Ex. B at 22-35.

b. Opinion

Dr. Staats opined “the medical record and the published literature do not support the

conclusion that [Petitioner’s AIED] and hearing loss was a result of the MMR vaccine.” Resp.

Ex. A at 13. He further opined there “no evidence” that the MMR vaccine caused Petitioner’s

AIED “via direct damage to the ear, inflammation, or molecular mimicry.” Id.

61

Dr. Staats submitted one expert report. Resp. Ex. A.

23

i. Althen Prong One

Dr. Staats summarized and responded to Dr. Monsell’s proposed causal mechanisms.

Resp. Ex. A at 4-5. He disagreed with Dr. Monsell’s conclusion that “the evidence of MMR

vaccine-induced injury” in Petitioner was “compelling.” Id. at 5.

Dr. Staats characterized Dr. Monsell’s causal theory as “vaccine viruses infecting the host

and causing hearing loss” due to the MMR vaccine containing live attenuated viruses. Resp. Ex.

A at 4. Dr. Staats described the distinctions in the immune response to a wild-type virus and a

live attenuated virus. Id. at 6. Relying on Lin et al., 62 Dr. Staats opined wild-type virus “results

in very different host exposure” compared to the live attenuated virus. Id. at 6-7 (citing Resp.

Ex. A, Tab 4).

Lin et al. examined the immune response of macaque monkeys to wild-type measles virus

and live attenuated measles virus. Resp. Ex. A, Tab 4 at 1. The route of administration was

through the respiratory tract. Id. at 2, 9. The authors found wild-type measles viruses

“replicated efficiently in B and T lymphocytes with spreading throughout lymphoid tissues

resulting in prolonged persistence of viral RNA” and live attenuated measles virus “replicated

efficiently in the respiratory tract but displayed limited spread to lymphoid tissue or peripheral

blood mononuclear cells.” Id. at 1. Three out of 12 macaques infected with the live attenuated

virus had detectable measles RNA in their peripheral blood mononuclear cells as compared to

the wild-type virus macaques, which all had detectable measles RNA after infection. Id. at 3.

None of the animals infected with the live attenuated measles virus had a rash in comparison to

those who received the wild-type virus, who all developed skin rashes. Id. Five of the 12

infected with the live attenuated measles virus had detectable measles RNA in their draining

lymph nodes. Id. The authors noted that a limitation of their study was that it did not address the

role of the subcutaneous immunization route and recommended further study of the effects of

route and dosing of live attenuated measles vaccines. Id. at 8.

Dr. Staats agreed “attenuated viruses in the vaccine are similar enough to the wild-type

virus to induce host immune response;” however, Dr. Staats asserted that the viral load of after

exposure to live attenuated virus is “much lower” than the viral load after exposure to wild-type

virus. Resp. Ex. A at 9. Dr. Staats further opined that “[c]onclusions based on infection with the

wild-type measles virus are not relevant to exposure to attenuated viruses used in the MMR

vaccine.” Id.

Dr. Staats disagreed the medical literature cited by Dr. Monsell discussing hearing loss

after wild-type measles, mumps, and/or rubella infections provided support for MMR vaccine-

induced hearing loss. Resp. Ex. A at 7-10. Dr. Staats noted that articles by Cohen et al.,

Dunmade et al., Fukada et al., and Olajuyin et al. all discussed wild-type infections and all

recommended MMR vaccinations. Id. at 8-9 (discussing Pet. Exs. 23, 24, 27, 43). Accordingly,

he opined that none of these articles provided support for or were relevant to Dr. Monsell’s

62

Wen-Hsuan W. Lin et al., A Durable Protective Immune Response to Wild-Type Measles

Virus Infection of Macaques Is Due to Viral Replication and Spread in Lymphoid Tissues, 12

Sci. Transl. Med. eaax7799 (2020).

24

theory. Id. Dr. Staats did not acknowledge that Cohen et al. discussed MMR vaccination as

“rarely associated with SNHL.” See id.; Pet. Ex. 23 at 9.

Responding to Dr. Monsell’s discussion of the inner ear inflammatory response, Dr.

Staats first criticized Dr. Monsell for not providing a “specific theory” that would “link the

MMR vaccination to inflammation in the inner ear and [Petitioner’s] hearing loss.” Resp. Ex. A

at 10. Next, Dr. Staats opined “vaccine-induced inflammation” causing hearing loss was not

supported by the results of Lin et al. Id. at 10, 11 fig.2 (citing Resp. Ex. A, Tab 4 at 7 fig.6). Dr.

Staats explained that while wild-type measles virus induced a “potent inflammatory response that

persists for days after infection,” the live attenuated virus exposure “does not induce robust

inflammation.” Id. at 10.

Addressing Dr. Monsell’s contention that the disease mechanism of syphilis-induced

SNHL (otosyphilis) demonstrated “the potential for infection to cause autoimmunity in the inner

ear with infection,” Dr. Staats acknowledged that syphilis infection “may induce an

inflammatory response to cause autoimmunity in the inner ear.” Resp. Ex. A at 11-12.

However, Dr. Staats again noted that the inflammatory response to live attenuated viruses found

in MMR vaccination “is very different to the host response to a live viral infection.” Id. at 12.

Accordingly, he opined the disease mechanism of otosyphilis did not support Dr. Monsell’s

theory of MMR-vaccine induced AIED. Id.

Moreover, Dr. Staats disagreed that Dr. Monsell or the medical literature provided

support for molecular mimicry as a mechanism for the MMR vaccine to cause AIED. Resp. Ex.

A at 12. Dr. Staats noted that molecular mimicry “is often discussed as a similarity in amino

acid sequence between a protein antigen in an infectious agent and a host protein that induces an

autoimmune disease.” Id. While Dr. Monsell invoked molecular mimicry in his report, he did

not identify “any regions of similarity between components of the MMR vaccine and host

antigens associated with [AIED].” Id. Dr. Staats cited a publication by Rojas et al. 63 that

identified structural homology for various viruses and autoimmune diseases. Id. (citing Resp.

Ex. A, Tab 6 at 4 tbl.1). Dr. Staats noted the authors did not identify “any antigens in measles,

mumps[,] or rubella that exhibit similarity to human antigens that would provide a basis for

molecular mimicry.” Id. Of note, Rojas et al. acknowledged that the generally referenced

criteria used to support molecular mimicry as a mechanism for a known pathogen are rarely

fulfilled. Resp. Ex. A, Tab 6 at 3 (“[Molecular mimicry] hypotheses are difficult to prove . . .

particularly for rare events/disease.”). Further, the authors list of infectious agents with

identified structural homology associated with a corresponding autoimmune disease is not

described as complete or exhaustive. See id. at 4 tbl.1.

Rojas et al. confirmed that molecular mimicry was “one of the likely mechanisms” for

the development of autoimmune disease and acknowledged that “environmental factors, such as .

. . vaccines, also have the potential to lead to autoimmunity not only via molecular mimicry but

63

Manuel Rojas et al., Molecular Mimicry and Autoimmunity in the Time of Covid-19, 139 J.

Autoimmun. 103070 (2023).

25

also by bystander activation, epitope-determinant spreading, and/or hapten carrier.” Resp. Ex. A,

Tab 6 at 2.

Next, Dr. Staats opined the “exact cause of hearing loss due to [AIED] has not yet been

determined.” Resp. Ex. A at 13. In support, Dr. Staats cited an article by Miwa and Okano 64

that described AIED as a “an idiopathic disorder characterized by unexpected hearing loss.” Id.

(quoting Resp. Ex. A, Tab 7 at 1). Miwa and Okano addressed the autoimmune nature of AIED,

noting that as “with most autoimmune diseases, it has been postulated that a misdirected assault

on the . . . inner ear proteins . . . activate[] the pro-inflammatory T-cell response and

autoantibody formation.” Resp. Ex. A, Tab 7 at 2. The authors explained that the inner ear is

“fully able to mount an immune response” to outside antigens. Id. at 6. The authors also noted

that AIED “represents much fewer than 1% of all cases of [SSNHL].” Id. at 1.

Turning to the medical literature on the association of MMR vaccination and hearing

loss, Dr. Staats observed that 2012 IOM report found “[t]he evidence inadequate to accept or

reject a causal relationship between MMR vaccine and hearing loss.” Resp. Ex. A at 5 (citing

Pet. Ex. 48 at 118). He further noted that the case reports discussed by the IOM had

symptomology of fever, rash, and nystagmus, which were not present in Petitioner. Id.

However, Petitioner’s medical records documented “very slight horizontal nystagmus” in

Petitioner. Pet. Ex. 2 at 794.

Dr. Staats opined that more recent vaccine safety reviews—by Maglione et al., 65 Gidengil

66

et al., and Baxter et al.—did not find an association between MMR vaccination and hearing

loss. Resp. Ex. A at 5-6 (citing Resp. Ex. A, Tab 1; Resp. Ex. A, Tab 2; Resp. Ex. A, Tab 3).

A 2014 safety review 67 by Maglione et al. sought to update the findings published in the

2012 IOM report. Resp. Ex. A, Tab 1 at 16. The authors, however, did not discuss hearing loss,

but instead addressed febrile seizures, thrombocytopenia, and other adverse effects. See id. at

126-27. The authors agreed with IOM conclusions that “evidence ‘convincingly’ supports a

causal relationship” between MMR vaccine and febrile seizures and that there is “moderate”

64

Toru Miwa & Takayuki Okano, Role of Inner Ear Macrophages and

Autoimmune/Autoinflammatory Mechanisms in the Pathophysiology of Inner Ear Disease, 13

Front. Neurol. 861992 (2022).

65

Margaret Maglione et al., Safety of Vaccines Used for Routine Immunization in the United

States, 215 Evid. Rep./Tech. Assess. 1 (2014).

66

Courtney Gidengil et al., Safety of Vaccines Used for Routine Immunization in the United

States: An Update, 244 Compar. Effectiveness Rev. 1 (2021).

67

This report was based on a systematic review of literature performed by the Southern

California Evidence-Based Practice Center (“EPC”) through a contract with the Agency for

Healthcare Research. See Resp. Ex. A, Tab 1 at 4, 8. The review by Gidengil et al. was also

prepared by the EPC. See Resp. Ex. A, Tab 2 at 3.

26

evidence to support an association between MMR vaccination and thrombocytopenic purpura in

children. Id. at 127. In his report, Dr. Staats acknowledged that Maglione et al. did not discuss

hearing loss. Resp. Ex. A at 5-6.

Gidengil et al. conducted a systematic of the literature on the safety of routine vaccines

administered in the United States with the goal of updating the 2014 report published by

Maglione et al. Resp. Ex. A, Tab 2 at 8. In their section on MMR vaccination, the authors

referenced the Baxter et al. study 68 noting it “detected no association between [SSNHL] and

MMR within one week of vaccination.” Id. at 11.

Baxter et al. analyzed seven years (2007 to 2013) of data from Kaiser Permanente

Northern California (“KPNC”) and identified 1,929 cases of SSNHL in the nine months

following any vaccine exposure and 57 cases of SSNHL within one week of vaccination. Resp.

Ex. A, Tab 3 at 1, 4. Using a case centered methodology, the authors did not find an association

between SSHL and any vaccination. Id. at 2. Specific to MMR, there were no cases of SSNHL

identified in the one-week risk interval after vaccination. Id. at 12 tbl.3. Relative to the

inactivated influenza vaccination, there were 167 cases in the risk interval of one to 28 days after

vaccination. Id. at 11 tbl. 2. The authors selected risk intervals of one to seven day, one to 14

days, one to 28 days, and 15 to 28 days. Id. at 4. They selected these intervals “through

literature and VAERS review as well as consultation with experts.” Id. at 6. They

acknowledged that a limitation of the study included the selection of risk intervals, “[i]f the

interval selected does not match the timing of increased risk an association may be missed.” Id.

For the MMR vaccine, the authors only included data from the one-week risk interval after

vaccination. Id. at 12 tbl. 3. Further, the number of cases of hearing loss following the MMR

vaccination occurring in day seven through 28 days is not known, because the supplemental

material was not filed with the article. See id. at 5. Additionally, the study design looked only at

diagnosis of SSNHL, and did not study SNHL or AIED following vaccination. Id. at 1-3.

Finally, Dr. Staats questioned the relevance of Dr. Monsell’s discussion of autoimmune

thrombocytopenia. Resp. Ex. A at 8. Dr. Staats noted Petitioner does not have autoimmune

thrombocytopenia and explained “the possible induction of one autoimmune condition

(autoimmune thrombocytopenia) does not equate to the induction of other autoimmune

diseases.” Id.

ii. Althen Prongs Two and Three

Dr. Staats opined “the medical record and the published literature do not support the

conclusion that [Petitioner’s AIED] and hearing loss was a result of the MMR vaccine.” Resp.

Ex. A at 13.

Addressing Dr. Monsell’s report, Dr. Staats argued there was “no discussion of a logical

sequence of cause and effect to support the theory that the MMR vaccine caused [Petitioner’s]

68

In his expert report, Dr. Staats explained that Baxter et al. was the study discussed by Gidengil

et al. in their vaccine safety review. Resp. Ex. A at 6. However, Respondent filed only an

excerpt of Gidengil et al. and the excerpt did not include the bibliography.

27

hearing loss.” Resp. Ex. A at 13. Dr. Staats also criticized the case reports provided by Dr.

Monsell as inconsistent with Petitioner’s clinical course in the present case. Id. at 7, 10, 12.

First, Dr. Staats noted that case report from Brodsky and Stanievich involved an

encephalitis-like reaction prior to the onset of SNHL. Resp. Ex. A at 7-8 (citing Pet. Ex. 21). As

Petitioner did not have any encephalitis-like symptoms after her MMR vaccine, Dr. Staats

opined this case report did not support the theory that the MMR vaccine caused Petitioner’s

hearing loss. Id. Of note, however, in their discussion of hearing loss cases following MMR

infection, Brodsky and Stanievich cite to literature describing “idiopathic” cases of severe

hearing loss where patients were noted to have an increased measles virus titer. Pet. Ex. 21 at 3.

Next, Dr. Staats distinguished Petitioner’s clinical course from the clinical course

reported in the Rikitake et al. child who developed bilateral acute hearing loss after mumps and

measles-rubella vaccination. Resp. Ex. A at 10 (citing Pet. Ex. 46). In Rikitake et al., 12 days

after vaccination, the patient experienced one day of fever, and the following day vomited once,

but then her symptoms abated. Pet. Ex. 46 at 2. Hearing loss was noted 18 days after

vaccination. Id. The authors concluded the vaccine “caused serious hearing loss in th[e] patient.”

Id. at 4. Dr. Staats noted Petitioner did not report fever or vomiting. Resp. Ex. A at 10.

Turning to the temporal association between the MMR vaccine and onset of Petitioner’s

AIED, Dr. Staats placed Petitioner’s onset as May 20 or 21, 2019 (approximately 30 days after

her second dose of MMR vaccine). Resp. Ex. A at 12. He did not rebut Dr. Monsell’s opinion

that this temporal association was appropriate given Petitioner’s proffered causal theory. Id. at

12-13.

3. Respondent’s Expert, Yu-Lan Mary Ying, M.D. 69

a. Background and Qualifications

Dr. Ying is “a fellowship trained otologist/neurotologist[] and [is] board certified in

otolaryngology and neurotology.” Resp. Ex. C at 1. After she obtained her M.D. in New York

from State University of New York (“SUNY”), Stony Brook School of Medicine, she completed

a general surgery internship and otolaryngology residency at the University of Pittsburgh

Medical Center. Resp. Ex. D at 1. Dr. Ying also completed a fellowship at the Howard Hughes

Medical Institute-National Institute of Health during medical school as well as a post-graduate

fellowship in otology/neurotology at Pittsburgh Ear Associates and a post-graduate fellowship in

neurotology at Baylor College of Medicine. Id. at 1-2. Since 2014, Dr. Ying has worked as an

assistant professor in the Otolaryngology-Head and Neck Surgery Department at Rutgers-New

Jersey Medical School. Id. at 2. She has also held various hospital appointments and

memberships in various professional societies, and she has served on several committees. Id. at

2-5. Dr. Ying has “a busy academic clinical practice treating many diverse patients with hearing,

balance[,] and lateral skull base disorders.” Resp. Ex. C at 1. She has co-authored over 30

publications throughout her career. Resp. Ex. D at 7-9.

69

Dr. Ying submitted one expert report. Resp. Ex. C.

28

b. Opinion

Dr. Ying agreed Petitioner’s bilateral SNHL was “most compatible with a diagnosis of

AIED.” Resp. Ex. C at 10. She disagreed, however, that there was sufficient evidence to

support Petitioner’s claim of “bilateral sudden SNHL, dizziness, and visual disturbances due to

an adverse reaction to MMR vaccination.” Id. at 8

i. Althen Prong One

Dr. Ying opined there was “insufficient scientific evidence indicating AIED is an adverse

event to MMR vaccination. There is no compelling evidence to establish causation between

MMR vaccination and AIED.” Resp. Ex. C at 10.

While Dr. Ying agreed measles and mumps infections can cause SNHL, Dr. Ying opined

AIED “has not been identified as a cause of SNHL after either measles or mumps infection.”

Resp. Ex. C at 6. Dr. Ying’s discussion of SNHL following natural measles and mumps

infection was largely consistent with Dr. Monsell’s description of SNHL following measles and

mumps infection. Id. at 5-6.

Dr. Ying agreed hearing loss was a common complication of measles infections. Resp.

Ex. C at 5. She noted measles-related hearing loss “is typically bilateral moderate to profound

SNHL and may follow measles encephalitis.” Id. Dr. Ying explained the pathogenesis of

measles encephalitis is “is due to the viral invasion of neurons resulting in inflammation of the

brain parenchyma.” Id. (citing Resp. Ex. C, Tab 7). 70 The Fisher et al. article cited by Dr. Ying

addressed the pathogenesis of measles encephalitis, explaining the virus is highly contagious and

usually spreads in the form of respiratory droplets, which infect cells in the alveoli of the

respiratory system. Resp. Ex. C, Tab 7 at 2-3. The infected cells drain into the lymph nodes,

and then the circulation, spreading to the skin, lung, liver, brain. Id. Hearing loss was not

specifically discussed.

After describing hearing loss caused by measles infection, Dr. Ying turned to mumps

infection. She opined that mumps “is the most common cause of acquired SNHL” and “has very

clearly been shown to be a cause of sudden SNHL.” Resp. Ex. C at 6 (citing Pet. Exs. 49-50).

She explained that SNHL “due to natural mumps infection results from endolymphatic

labyrinthitis, an inflammation of the membranous labyrinth of the inner ear as the primary route

of invasion of the virus is hematogenous.” 71 Id. (citing Resp. Ex. C, Tab 11). 72 In Mizushima

70

D.L. Fisher et al., Measles-Induced Encephalitis, 108 QJM 177 (2015).

71

Hematogenous means “disseminated by the circulation or through the bloodstream.”

Hematogenous, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=21756 (last visited Dec. 18, 2025).

72

Norio Mizushima & Yoshihiko Murakami, Deafness Following Mumps: The Possible

Pathogenesis and Incidence of Deafness, 13 Auris Nasus Larynx (Tokyo) S55 (1986).

29

and Murakami, the authors opined hematogenous infection was the “most probable” mechanism

of deafness due to mumps. Resp. Ex. C, Tab 11 at 2. The authors explained “the viremic state

due to mumps reaches the inner ear hematogenously, causes an inflammatory change in the stria

vascularis of the cochlea and then results in severe impairment of the endolymphatic system.”

Id. They also noted hearing loss in mumps was not associated with meningitis or

meningoencephalitis. Id.

Turning to the incubation period for these infections, Dr. Ying agreed the incubation

period of natural measles or rubella virus infection is about two weeks, and the incubation period

of mumps virus is about two to three weeks. Resp. Ex. C at 6. She explained in mumps-related

hearing loss, SNHL tends to occur four to five days after “onset of signs of infection such as flu-

like symptoms and parotitis.” 73 Id. (citing Pet. Ex. 30). Dr. Ying also acknowledged mumps-

induced SNHL can occur in asymptomatic cases of mumps. Id. (citing Resp. Ex. C, Tab 10). 74

Next, Dr. Ying reviewed the medical literature reporting an association between MMR

vaccination and SNHL. Resp. Ex. C at 6-7. Dr. Ying explained that the MMR vaccination

“includes live[]attenuated measles and mumps viruses.” Id. at 6. She acknowledged that

“[t]here are case reports that have associated MMR vaccination with SNHL in rare

circumstances.” Id. Cases of hearing loss associated with MMR vaccination vary in “severity,

can be bilateral or unilateral,” and have “been reported in both pediatric and adult patients.” Id.

Dr. Ying discussed case reports of bilateral acute SNHL occurring after the mumps and

MMR vaccinations. Resp. Ex. C at 7. Rikitake et al. reported bilateral acute hearing loss

approximately three weeks after receipt of the mumps vaccine. Id. (citing Pet. Ex. 46 at 3-4).

She emphasized that the “[m]umps vaccine was considered the cause based on the incubation

period.” Id. Next, Hulbert et al. described a patient who developed bilateral acute profound

hearing loss 22 days after MMR vaccination. Id. (citing Pet. Ex. 32). Finally, Stewart and

Prabhu reviewed nine cases of hearing loss after MMR vaccination, and in six they suggested

that vaccine causation was “one possibility.” Id. (citing Pet. Ex. 47 at 2). Dr. Ying emphasized

that “published case reports are only anecdotes and speculations of MMR vaccination resulting

in SNHL” and “might represent coincidental observations.” Id.

Additionally, Dr. Ying noted that both the 1994 and 2012 assessments by the IOM

committee found insufficient evidence to establish a causal relationship. Resp. Ex. C at 7 (citing

73

Parotitis is “inflammation of the parotid gland,” which is part of the salivary glands. Parotitis,

Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/dorland/definition?

id=37103 (last visited Dec. 19, 2025); Glandula Parotidea, Dorland’s Med. Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=78815 (last visited Dec. 19, 2025).

74

Hiromi Hashimoto et al., An Office-Based Prospective Study of Deafness in Mumps, 28

Pediatr. Infect. Dis. J. 173 (2009).

30

Resp. Ex. C, Tab 14; 75 Pet. Ex. 48). The 2012 IOM committee assessed the mechanistic

evidence regarding an association between measles or mumps vaccine and hearing loss as “low-

intermediate based on knowledge about the natural infection, experimental evidence, and eight

cases.” Id. (quoting Pet. Ex. 48 at 118). Regarding natural infection, the committee noted that

the wild-type mumps virus infection was associated with deafness and the wild-type measles

infection was associated with bilateral “hearing loss in [five to 10] percent of measles cases.”

Pet. Ex. 48 at 117. “The committee considers the effects of natural infection one type of

mechanistic evidence.” Id. Experimental evidence included the detection of anti-mumps

antibodies in patients who developed idiopathic SSNHL and the finding of measles antigen in

animal cochlear ducts. Id. at 118. These findings “suggested the involvement of measles and

mumps viruses in the pathogenesis of hearing loss.” Id. As Dr. Ying noted in her report, the

IOM committee ultimately determined the evidence was “inadequate to accept or reject a causal

relationship between MMR vaccine and hearing loss.” 76 Resp. Ex. C at 7 (quoting Pet. Ex. 48 at

118). Dr. Ying noted weaknesses in the evidence reviewed by the IOM committee were due to

“publications of a case report that did not provide evidence beyond temporality” and “long

latencies between vaccine administration and development of symptoms mak[ing] it impossible

to rule out other possible causes.” Id.

Dr. Ying provided medical literature that discussed the pathogenesis of AIED. See, e.g.,

Resp. Ex. C, Tab 16. 77 Vambutas and Pathak explained that “[a]s with most autoimmune

diseases, it has been postulated that a misdirected attack on self, in this case to inner ear proteins,

results in both proinflammatory T-cell responses and autoantibody formation, which represent

the basic features of AIED and other autoimmune diseases.” Id. at 2; see also Resp. Ex. C, Tab

17 at 3-4 (discussing the mechanisms of autoimmune process in the inner ear); 78 Resp. Ex. C,

Tab 18 at 2 (“An uncontrolled attack against inner ear antigens, resulting in both T-cell responses

and autoantibody development, has been proposed as the pathogenetic mechanism of AIED”).

In Ciorba et al., the authors noted this immunological process may result in cochlear and

vestibular damage with the most commonly reported damage being “cochlear vasculitis, atrophy

75

Kathleen Stratton et al., Adverse Events Associated with Childhood Vaccines Other Than

Pertussis and Rubella: Summary of a Report from the Institute of Medicine, 271 JAMA 1602

(1994).

76

The IOM committee defines this category of causation as evidence that “is not reasonably

convincing either in support of or against causality; evidence that is sparse, conflicting, of weak

quality, or merely suggestive—whether toward or away from causality falls in this category.”

2012 IOM report at 15, 23-24. Of note, the IOM committee determined that the “epidemiologic

evidence was insufficient or absent to assess an association between MMR vaccine and hearing

loss.” Pet. Ex. 48 at 115.

77

Andrea Vambutas & Shresh Pathak, AAO: Autoimmune and Autoinflammatory (Disease) in

Otology: What Is New in Immune-Mediated Hearing Loss, 1 Laryngoscope Investig.

Otolaryngol. 110 (2016).

78

R. Bovo et al., Immune-Mediated Inner Ear Disease, 126 Acta Otolaryngol. 1012 (2006).

31

of the organ of Corti, otic capsule otospongiosis,[79] endolymphatic hydrops[, 80] and spiral

ganglion degeneration.” 81 Resp. Ex. C, Tab 18 at 2.

Additionally, Vambutas and Pathak noted while the pathogenesis contemplates

autoantibody formation, no autoantibodies have been found specific to AIED. 82 Resp. Ex. C,

Tab 16 at 2. In a small group of patients, anti-cochlin antibodies have been reported that “would

represent a cochlear specific antibody response.” Id. Studies about AIED are difficult due to

limited access of the cochlea, that fact that peripheral blood immune markers may not reflect

inner ear immune reactions, and animal studies have been limited. Id.; see also Resp. Ex. C, Tab

18 at 2. Research also suggests that like other autoimmune diseases, AIED may be both an

autoimmune and an autoinflammatory disease. Resp. Ex. C, Tab 16 at 2.

Bovo et al. described the “three levels of proof” used in the diagnosis of an autoimmune

disease like AIED. Resp. Ex. C, Tab 17 at 1. The three levels of proof, in “descending order of

importance” are “(i) direct proof; (ii) indirect proof; and (iii) circumstantial evidence.” Id. The

authors explained that obtaining direct proof, through “the induction of disease in humans by

transferring autoantibodies or autoreactive T cells,” was ethically untenable. Id. Instead,

researchers must rely upon indirect proof, such as animal models, and circumstantial evidence.

Id. at 1-2. Looking at experimental models (a type of indirect proof), the authors explained a

“wide variety of antibodies against different ear tissues have been detected [in AIED],” and

“multiple antigens” have also been recognized, but none have been identified as “the specific

target.” Id. at 2. The authors concluded that based on available “clinical and experimental data

there is [] strong evidence of immune mechanisms in human inner ear disease.” Id. Bovo et al.

provided a detailed review of the immune system of the inner ear, noting there is “substantial

evidence of autoimmune mechanisms in . . . sudden deafness.” Id. at 3. Significantly, Bovo et

al. noted that the “‘cross-reactions’ theory is [] the most favored [mechanism]: antibodies or

79

Otospongiosis is “the formation of spongy bone in the bony labyrinth of the ear.”

Otospongiosis, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=35990 (last visited Dec. 19, 2025).

80

Endolymphatic hydrops is “an abnormal accumulation of endolymphatic fluid within the

membranous labyrinth of the inner ear.” Mickie Hamiter, Meniere Disease, Merck Manual,

https://www.merckmanuals.com/professional/ear-nose-and-throat-disorders/inner-ear-

disorders/meniere-disease (last visited Dec. 16, 2025).

81

The spiral ganglion is located within the cochlea and “consists of bipolar cells that send fibers

peripherally through the foramina nervosa to the spiral organ and centrally through the internal

acoustic meatus [auditory canal] to the cochlear nuclei of the brainstem.” See Ganglion

Cochleare, Dorland’s Med. Dictionary Online, https://www.dorlandsonline.com/

dorland/definition?id=78034 (last visited Dec. 19, 2025).

82

Bovo et al. explained clinical testing is not currently done to identify antibodies “to an inner

ear supporting cell antigen.” Resp. Ex. C, Tab 17 at 6.

32

rogue T cells cause accidental inner ear damages because the ear share common antigens with . .

. a virus . . . the body is fighting off.” Id. Other mechanisms were also discussed. 83 Id. at 3-4.

Additionally, Dr. Ying criticized several aspects of Dr. Monsell’s report. First, Dr. Ying

opined the mechanisms of vaccine-induced autoimmunity proposed by Agmon-Levin et al. “are

only just theories as there is still no published evidence demonstrating how MMR vaccine causes

AIED.” Resp. Ex. C at 9 (citing Pet. Ex. 14). Citing Agmon-Levin et al., Dr. Ying explained

“the role of other risk cofactors including environmental exposures [or] genetic susceptibility . . .

may affect the causal association between vaccination and autoimmunity.” Id. (citing Pet. Ex. 14

at 4). Dr. Ying observed that Dr. Monsell did not discuss the risk co-factors in Petitioner’s case.

Id. Although Dr. Ying described co-factors such as environmental exposures and genetic

susceptibility, she did not describe these in any detail or suggest that they independently can

cause AIED. Id.

Next, Dr. Ying faulted Dr. Monsell for not elaborating on his comment that “complex

microbiological processes that could be subject to functionally different genetic variants in

vaccine recipients and idiosyncratic reactions.” Resp. Ex. C at 9. Dr. Ying described this

statement as vague and noted it was unclear what “idiosyncratic reactions” Dr. Monsell was

referencing. Id.

Dr. Ying also criticized Dr. Monsell’s use of autoimmune thrombocytopenia as example

of MMR vaccination causing an autoimmune condition. Resp. Ex. C at 9. Dr. Ying opined “the

same process does not apply to hearing loss or inner ear.” Id. Dr. Ying did not provide further

explanation on the differences between autoimmune thrombocytopenia and AIED. Dr. Ying also

noted that there is no animal model for AIED to allow for “vaccine experiments.” Id.

Dr. Ying concluded “[i]n publications to date, there is insufficient scientific evidence

indicating AIED is an adverse event to MMR vaccination.” Resp. Ex. C at 10.

iii. Althen Prongs Two and Three

Dr. Ying opined there was “insufficient evidence” that Petitioner’s bilateral SNHL,

dizziness, and visual disturbances were an adverse reaction to the MMR vaccine. Resp. Ex. C at

8. Further, Dr. Ying disagreed that the onset of Petitioner’s AIED was “consistent with an

immune-mediated response following MMR vaccination.” Id. at 10.

First, Dr. Ying explained Petitioner’s clinical presentation was not consistent with

published case reports or the medical literature. Resp. Ex. C at 8. Petitioner did not experience

any adverse symptomatology such as fever or arthralgia after her MMR vaccination. Id. And, as

discussed further below, her hearing loss occurred outside the incubation period for mumps or

measles infection cited in the published case reports. Id. Dr. Ying further noted that Petitioner’s

serial MRIs were unremarkable and did not contain the high signal intensities in the cochlea

described by Otake et al. Id. (citing Pet. Ex. 45). However, Otake et al. noted the high signal

83

For another paper with a thorough discussion about the proposed mechanisms of AIED, see

Resp. Ex. C, Tab 18.

33

intensity present in the 3D-FLAIR imaging was not detected by T1 and T2 weighted MRIs taken

in the same patient. Pet. Ex. 45 at 2. Additionally, Dr. Ying opined Petitioner’s “subjective

visual complaints” were not commonly seen in measles, mumps, or rubella infection. Resp. Ex.

C at 8.

Next, Dr. Ying noted Petitioner did not report “any problem/side effects with the first

MMR vaccination administered on March 15, 2022.” Resp. Ex. C at 8. As Petitioner was

“already exposed to a first dose of MMR vaccine,” Dr. Ying opined the second dose of MMR

administered 30 days later “should not be so novel to trigger another autoimmune response.” Id.

Dr. Ying disagreed that Dr. Monsell’s comment that “MMR vaccine is not often

administered to adults, who may not have as robust an immune system as children” provided

support for vaccination causation in Petitioner. Resp. Ex. C at 9. She opined that if adults have

a less robust immune system, “then the incidence/occurrence of vaccine-induced autoimmunity

should be less in adults.” Id.

Additionally, Dr. Ying noted Petitioner’s hearing loss symptoms appeared “at the end of

her vacation in Hawaii.” Resp. Ex. C at 9. Dr. Ying opined “stressors from vacation/traveling

away from home could trigger immune responses.” Id. Dr. Ying noted “these stressors”

occurred closer in time to Petitioner’s hearing loss than her MMR vaccination. Id. Dr. Ying

suggested additional information regarding Petitioner’s “well-being” and symptoms at the end of

her vacation “could provide clues of other possible explanations.” Id.

Discussing the temporal relationship between Petitioner’s MMR vaccination and the

onset of her AIED, Dr. Ying explained Petitioner first reported muffled hearing/hearing loss 31

to 32 days after receiving her second dose of the MMR vaccine. Resp. Ex. C at 8. Dr. Ying

opined a 31/32-day onset is outside of the incubation period for measles and mumps infections.

Id. She reported the incubation for measles is 10 to 12 days “from exposure to prodrome” and

seven to 21 from exposure to rash. 84 Id. And Dr. Ying noted case reports that have associated

MMR vaccination with SNHL have a time course of onset corresponding to the incubation

period of measles infection. Id. at 6 (citing Pet. Ex. 23). Additionally, the case report from

Rikitake et al. described an onset of 18 days consistent with the incubation period of mumps. Id.

at 7 (citing Pet. Ex. 46). While the bilateral SNHL reported in Hulbert et al. had onset of 22

days, Dr. Ying noted the patient had “body reaction (arthralgias, fever, headaches, tinnitus,

dizziness) three days after she receive[d ]MMR vaccination.” Id. (citing Pet. Ex. 32).

Finally, Dr. Ying opined Petitioner’s theory that the onset of her AIED was “consistent

with an immune-mediated response following MMR vaccination” was “not based on a

reasonable degree of medical probability.” Resp. Ex. C at 10. As discussed above, Dr. Ying

disagreed that Dr. Monsell’s discussion MMR vaccine-induced thrombocytopenia was applicable

to AIED. Id. at 9. Dr. Ying did not discuss what a medically appropriate timeframe would be

for an immune‐mediated response following vaccination.

84

Dr. Ying cited Epidemiology and Prevention of Vaccine-Preventable Diseases (Elisha Hall et

al. eds., 14th ed. 2021) in support of the incubation period of measles infection; however, this

source was not filed as an exhibit by Respondent.

34

Dr. Ying concluded, “[m]ore than likely, [Petitioner] suffered ‘idiopathic’ AIED without

any association to her two doses of MMR vaccinations.” Resp. Ex. C at 10.

III. LEGAL FRAMEWORK

A. Standards for Adjudication

The Vaccine Act was established to compensate vaccine-related injuries and deaths. §

10(a). “Congress designed the Vaccine Program to supplement the state law civil tort system as

a simple, fair and expeditious means for compensating vaccine-related injured persons. The

Program was established to award ‘vaccine-injured persons quickly, easily, and with certainty

and generosity.’” Rooks v. Sec’y of Health & Hum. Servs., 35 Fed. Cl. 1, 7 (1996) (quoting

H.R. Rep. No. 908 at 3, reprinted in 1986 U.S.C.C.A.N. at 6287, 6344).

Petitioner’s burden of proof is by a preponderance of the evidence. § 13(a)(1). The

preponderance standard requires a petitioner to demonstrate that it is more likely than not that the

vaccine at issue caused the injury. Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315,

1322 n.2 (Fed. Cir. 2010). Proof of medical certainty is not required. Bunting v. Sec’y of Health

& Hum. Servs., 931 F.2d 867, 873 (Fed. Cir. 1991). Petitioner need not make a specific type of

evidentiary showing, i.e., “epidemiologic studies, rechallenge, the presence of pathological

markers or genetic predisposition, or general acceptance in the scientific or medical communities

to establish a logical sequence of cause and effect.” Capizzano v. Sec’y of Health & Hum.

Servs., 440 F.3d 1317, 1325 (Fed. Cir. 2006). Instead, Petitioner may satisfy her burden by

presenting circumstantial evidence and reliable medical opinions. Id. at 1325-26.

In particular, a petitioner must prove that the vaccine was “not only [the] but-for cause of

the injury but also a substantial factor in bringing about the injury.” Moberly, 592 F.3d at 1321

(quoting Shyface v. Sec’y of Health & Hum. Servs., 165 F.3d 1344, 1352-53 (Fed. Cir. 1999));

see also Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1355 (Fed. Cir. 2006). The

received vaccine, however, need not be the predominant cause of the injury. Shyface, 165 F.3d

at 1351. A petitioner who satisfies this burden is entitled to compensation unless Respondent

can prove, by a preponderance of the evidence, that the vaccinee’s injury is “due to factors

unrelated to the administration of the vaccine.” § 13(a)(1)(B). However, if a petitioner fails to

establish a prima facie case, the burden does not shift. Bradley v. Sec’y of Health & Hum.

Servs., 991 F.2d 1570, 1575 (Fed. Cir. 1993).

“Regardless of whether the burden ever shifts to the [R]espondent, the special master

may consider the evidence presented by the [R]espondent in determining whether the [P]etitioner

has established a prima facie case.” Flores v. Sec’y of Health & Hum. Servs., 115 Fed. Cl. 157,

162-63 (2014); see also Stone v. Sec’y of Health & Hum. Servs., 676 F.3d 1373, 1379 (Fed. Cir.

2012) (“[E]vidence of other possible sources of injury can be relevant not only to the ‘factors

unrelated’ defense, but also to whether a prima facie showing has been made that the vaccine

was a substantial factor in causing the injury in question.”); de Bazan v. Sec’y of Health & Hum.

Servs., 539 F.3d 1347, 1353 (Fed. Cir. 2008) (“The government, like any defendant, is permitted

to offer evidence to demonstrate the inadequacy of the [P]etitioner’s evidence on a requisite

35

element of the [P]etitioner’s case-in-chief.”); Pafford, 451 F.3d at 1358-59 (“[T]he presence of

multiple potential causative agents makes it difficult to attribute ‘but for’ causation to the

vaccination. . . . [T]he Special Master properly introduced the presence of the other unrelated

contemporaneous events as just as likely to have been the triggering event as the vaccinations.”).

B. Factual Issues

Petitioner must prove, by a preponderance of the evidence, the factual circumstances

surrounding her claim. § 13(a)(1)(A). To resolve factual issues, the special master must weigh

the evidence presented, which may include contemporaneous medical records and testimony.

See Burns v. Sec’y of Health & Hum. Servs., 3 F.3d 415, 417 (Fed. Cir. 1993) (explaining that a

special master must decide what weight to give evidence including oral testimony and

contemporaneous medical records).

Medical records, specifically contemporaneous medical records, are presumed to be

accurate and generally “warrant consideration as trustworthy evidence.” Cucuras v. Sec’y of

Health & Hum. Servs., 993 F.2d 1525, 1528 (Fed. Cir. 1993). But see Kirby v. Sec’y of Health

& Hum. Servs., 997 F.3d 1378, 1382 (Fed. Cir. 2021) (rejecting the presumption that “medical

records are accurate and complete as to all the patient’s physical conditions”); Shapiro v. Sec’y

of Health & Hum. Servs., 101 Fed. Cl. 532, 538 (2011) (“[T]he absence of a reference to a

condition or circumstance is much less significant than a reference which negates the existence

of the condition or circumstance.” (quoting Murphy v. Sec’y of Health & Hum. Servs., 23 Cl. Ct.

726, 733 (1991), aff’d per curiam, 968 F.2d 1226 (Fed. Cir. 1992))), recons. den’d after remand,

105 Fed. Cl. 353 (2012), aff’d mem., 503 F. App’x 952 (Fed. Cir. 2013). The weight afforded to

contemporaneous records is due to the fact that they “contain information supplied to or by

health professionals to facilitate diagnosis and treatment of medical conditions. With proper

treatment hanging in the balance, accuracy has an extra premium.” Id. To overcome the

presumptive accuracy of medical records, a petitioner may present testimony which is

“consistent, clear, cogent, and compelling.” Sanchez v. Sec’y of Health & Hum. Servs., No. 11-

685V, 2013 WL 1880825, at *3 (Fed. Cl. Spec. Mstr. Apr. 10, 2013) (citing Blutstein v. Sec’y of

Health & Hum. Servs., No. 90-2808V, 1998 WL 408611, at *5 (Fed. Cl. Spec. Mstr. June 30,

1998)), mot. for rev. den’d, 142 Fed. Cl. 247 (2019), vacated on other grounds & remanded, 809

F. App’x 843 (Fed Cir. 2020).

There are situations in which compelling testimony may be more persuasive than written

records, such as where records are deemed to be incomplete or inaccurate. Campbell v. Sec’y of

Health & Hum. Servs., 69 Fed. Cl. 775, 779 (2006) (“[L]ike any norm based upon common

sense and experience, this rule should not be treated as an absolute and must yield where the

factual predicates for its application are weak or lacking.”); Lowrie v. Sec’y of Health & Hum.

Servs., No. 03-1585V, 2005 WL 6117475, at *19 (Fed. Cl. Spec. Mstr. Dec. 12, 2005)

(“[W]ritten records which are, themselves, inconsistent, should be accorded less deference than

those which are internally consistent.” (quoting Murphy, 23 Cl. Ct. at 733)). Ultimately, a

determination regarding a witness’s credibility is needed when determining the weight that such

testimony should be afforded. Andreu v. Sec’y of Health & Hum. Servs., 569 F.3d 1367, 1379

(Fed. Cir. 2009); Bradley, 991 F.2d at 1575.

36

Despite the weight afforded medical records, special masters are not bound rigidly by

those records in determining onset of a petitioner’s symptoms. Valenzuela v. Sec’y of Health &

Hum. Servs., No. 90-1002V, 1991 WL 182241, at *3 (Fed. Cl. Spec. Mstr. Aug. 30, 1991); see

also Eng v. Sec’y of Health & Hum. Servs., No. 90-1754V, 1994 WL 67704, at *3 (Fed. Cl.

Spec. Mstr. Feb. 18, 1994) (Section 13(b)(2) “must be construed so as to give effect also to §

13(b)(1) which directs the special master or court to consider the medical records (reports,

diagnosis, conclusions, medical judgment, test reports, etc.), but does not require the special

master or court to be bound by them”).

C. Causation

To receive compensation through the Program, Petitioner must prove either (1) that she

suffered a “Table Injury”—i.e., an injury listed on the Vaccine Injury Table—corresponding to a

vaccine that she received, or (2) that she suffered an injury that was actually caused by a

vaccination. See §§ 11(c)(1), 13(a)(1)(A); Capizzano, 440 F.3d at 1319-20. Petitioner must

show that the vaccine was “not only a but-for cause of the injury but also a substantial factor in

bringing about the injury.” Moberly, 592 F.3d at 1321 (quoting Shyface, 165 F.3d at 1352-53).

Because Petitioner does not allege she suffered a Table Injury, she must prove a vaccine

actually caused her injury. To do so, Petitioner must establish, by preponderant evidence: “(1) a

medical theory causally connecting the vaccination and the injury; (2) a logical sequence of

cause and effect showing that the vaccination was the reason for the injury; and (3) a showing of

a proximate temporal relationship between vaccination and injury.” Althen, 418 F.3d at 1278.

The causation theory must relate to the injury alleged. Petitioner must provide a sound

and reliable medical or scientific explanation that pertains specifically to this case, although the

explanation need only be “legally probable, not medically or scientifically certain.” Knudsen v.

Sec’y of Health & Hum. Servs., 35 F.3d 543, 548-49 (Fed. Cir. 1994). Petitioner cannot

establish entitlement to compensation based solely on her assertions; rather, a vaccine claim must

be supported either by medical records or by the opinion of a medical doctor. § 13(a)(1). In

determining whether Petitioner is entitled to compensation, the special master shall consider all

material in the record, including “any . . . conclusion, [or] medical judgment . . . which is

contained in the record regarding . . . causation.” § 13(b)(1)(A). The special master must weigh

the submitted evidence and the testimony of the parties’ proffered experts and rule in Petitioner’s

favor when the evidence weighs in his favor. See Moberly, 592 F.3d at 1325-26 (“Finders of

fact are entitled—indeed, expected—to make determinations as to the reliability of the evidence

presented to them and, if appropriate, as to the credibility of the persons presenting that

evidence.”); Althen, 418 F.3d at 1280 (noting that “close calls” are resolved in Petitioner’s

favor).

Testimony that merely expresses the possibility—not the probability—is insufficient, by

itself, to substantiate a claim that such an injury occurred. See Waterman v. Sec’y of Health &

Hum. Servs., 123 Fed. Cl. 564, 573-74 (2015) (denying Petitioner’s motion for review and

noting that a possible causal link was not sufficient to meet the preponderance standard). The

Federal Circuit has made clear that the mere possibility of a link between a vaccination and a

petitioner’s injury is not sufficient to satisfy the preponderance standard. Moberly, 592 F.3d at

37

1322 (emphasizing that “proof of a ‘plausible’ or ‘possible’ causal link between the vaccine and

the injury” does not equate to proof of causation by a preponderance of the evidence); Boatmon

v. Sec’y of Health & Hum. Servs., 941 F.3d 1351, 1359-60 (Fed. Cir. 2019). While certainty is

by no means required, a possible mechanism does not rise to the level of preponderance.

Moberly, 592 F.3d at 1322; see also de Bazan, 539 F.3d at 1351.

IV. ANALYSIS

A. Althen Prong One

Under Althen prong one, Petitioner must set forth a medical theory explaining how the

received vaccine could have caused the sustained injury. Andreu, 569 F.3d at 1375; Pafford, 451

F.3d at 1355-56. Petitioner’s theory of causation need not be medically or scientifically certain,

but it must be informed by a “sound and reliable” medical or scientific explanation. Boatmon,

941 F.3d at 1359; see also Knudsen, 35 F.3d at 548; Veryzer v. Sec’y of Health & Hum. Servs.,

98 Fed. Cl. 214, 257 (2011) (noting that special masters are bound by both § 13(b)(1) and

Vaccine Rule 8(b)(1) to consider only evidence that is both “relevant” and “reliable”). If

Petitioner relies upon a medical opinion to support his theory, the basis for the opinion and the

reliability of that basis must be considered in the determination of how much weight to afford the

offered opinion. See Broekelschen, 618 F.3d at 1347 (“The special master’s decision often times

is based on the credibility of the experts and the relative persuasiveness of their competing

theories.”); Perreira v. Sec’y of Health & Hum. Servs., 33 F.3d 1375, 1377 n.6 (Fed. Cir. 1994)

(stating that an “expert opinion is no better than the soundness of the reasons supporting it”

(citing Fehrs v. United States, 620 F.2d 255, 265 (Ct. Cl. 1980))).

The undersigned finds that Petitioner has provided preponderant evidence of a sound and

reliable causal mechanism as required under Althen prong one for the following reasons.

First, the parties’ experts agree that Petitioner’s diagnosis is AIED, autoimmune inner ear

disease. Thus, there is agreement that the diagnosis at issue here is autoimmune in nature.

Next, both parties’ experts and their referenced medical literature provide strong evidence

of the following foundational support: (1) The inner ear is not immunologically privileged, (2)

the inner ear has a robust immune system and can generate a destructive immune response, (3)

viruses are common causes of autoimmune conditions, (4) measles and mumps virus infections

are associated with SSNHL, and (5) MMR vaccines are associated with hearing loss as shown in

case reports.

While one case report may not provide persuasive evidence of causation, here there are

numerous cases of MMR vaccine associated hearing loss. While case reports are generally

insufficient to establish causation, they do provide some evidence in favor of causation. See,

e.g., Coleman v. Sec’y of Health & Hum. Servs., No. 18-352V, 2021 WL 1291677, at *13 (Fed.

Cl. Spec. Mstr. Feb. 16, 2021); Campbell v. Sec’y of Health & Hum. Servs., 97 Fed. Cl. 650, 668

(2011) (“[C]ase reports can by their nature only present indicia of causation but that does not

deprive them of all evidentiary weight.”). For rare conditions, case reports carry more weight

than would otherwise be afforded. Raymo v. Sec’y of Health & Hum. Servs., No. 11-0654V,

38

2014 WL 1092274, at *21 (Fed. Cl. Spec. Mstr. Feb. 24, 2014) (granting “more significance” to

case reports when the injury at issue was a “relatively rare condition” with “with only about 1400

new cases in the U.S. diagnosed annually”); see also Songero v. Sec’y of Health & Hum. Servs.,

No. 18-300V, 2025 WL 3013090, at *16 (Fed. Cl. Spec. Mstr. Oct. 3, 2025) (“In the context of

rare conditions, [] where epidemiologic studies are unavailable, [case reports] provide some

evidence of causation.”). Moreover, the IOM committee considered case reports in determining

their assessment as to a mechanistic theory. The committee identified specific publications,

including case reports, that provided “clinical, [or] diagnostic . . . evidence that contributed to the

weight of the mechanistic evidence.” Pet. Ex. 48 at 115.

Agmon-Levin et al. supports the third foundational tenet above and explains the nexus

with molecular mimicry. They state “[i]nfectious agents are considered to be the most common

triggers of autoimmunity, and vaccines that contain antigens from infectious agents might

induced autoimmunity by similar mechanisms such as molecular mimicry, bystander activation,

epitope spreading, and polyclonal activation.” Pet. Ex. 14 at 2. The MMR vaccine contains

antigens of the measles and mumps viruses and are infectious agents which historically are

known to induce autoimmune diseases by the mechanism of molecular mimicry.

Further, these foundational tenets formed the basis of the 2012 IOM assessment about the

mechanistic evidence related to hearing loss following measles or mumps vaccinations. The

IOM’s assessment of low-intermediate was “based on knowledge about the natural infection,

experimental cases[,] and eight [case reports].” Pet. Ex. 48 at 118. Although the parties here

disagree about the import of the assessment “low-intermediate,” the undersigned finds that since

the 2012 IOM report, the body of knowledge about hearing loss and AIED has grown. While no

specific vaccine antigens triggering AIED have been identified, and no specific autoantibodies

discovered to prove causation with certainty, molecular mimicry has emerged as the favored

causal theory. Due to the information described in the articles about AIED filed herein,

combined with knowledge about natural infections of measles and mumps and hearing loss, the

knowledge that viral infections cause autoimmune conditions, clinical and experimental data,

and numerous case reports, the undersigned finds there is preponderant evidence that the MMR

vaccine can cause AIED through molecular mimicry as well as the other mechanisms identified

by Dr. Monsell.

Because much about the pathogenesis of AIED is not known, Respondent asserts there is

“inadequate reliable evidence to convincingly establish a causal association.” Resp. Response at

15-16. However, a lack of knowledge does not automatically preclude a finding of preponderant

evidence in Vaccine Act cases. Bovo et al. explained that the diagnosis of an autoimmune

disease like AIED “relies on three levels of proof . . . (i) direct proof; (ii) indirect proof; and (iii)

circumstantial evidence.” Resp. Ex. C, Tab 17 at 1. While there is no direct proof, there is

indirect proof and circumstantial evidence from experimental models of autoimmune hearing

loss in animals, serology findings in animal models that correlate to serology studies in humans,

assessment of autoimmune activity detected by various lab studies, and the finding of multiple

antibodies against different ear tissues. Bovo et al. note that the observation of inner ear

antibodies “does not always support the cause-and-effect link needed to demonstrate correlation

between antibodies and inner ear disease.” Id. at 2. They conclude, however, that “based on all

these clinical and experimental data there is today strong evidence of immune mechanisms in

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human inner ear disease.” Id. Further, they identify a “cross-reactions theory” as the “most

favored” mechanism for the autoimmune process in the inner ear. Id. at 3.

Moreover, circumstantial evidence is applicable in the context of vaccine causation. See,

e.g., Patton v. Sec’y of Health & Hum. Servs., 157 Fed. Cl. 159, 164 (2021) (“The Vaccine Act

permits proof of causation through ‘the use of circumstantial evidence envisioned by the

preponderance standard.’” (quoting Capizzano., 440 F.3d at 1325)); Harr v. Sec’y of Health &

Hum. Servs., 107 Fed. Cl. 280, 304 (2012) (“[C]ircumstantial evidence is sometimes enough to

prove causation in a Vaccine Act case.”); see also R.G.C. & S.S.C. ex rel. A.G.C. v. Sec’y of

Health & Hum. Servs., No. 18-1624V, 2025 WL 3142007, at *29 (Fed. Cl. Spec. Mstr. Aug. 28,

2025) (“Experts who testify in this Program often must extrapolate a study’s findings then apply

that to the case before them. Although doing so does not prove that the subject vaccine can

cause the alleged injury to the degree of scientific certainty, it may provide circumstantial

evidence that advances a sound and reliable theory.”) (citing Doles v. Sec’y of Health & Hum.

Servs., No. 2023-2404, 2025 WL 1177875, at *5-9 (Fed. Cir. 2025)).

Next, Respondent asserts that because there are no supportive epidemiological studies

showing a causal association between the MMR vaccine and AIED, Petitioner cannot prevail.

However, it is well established by case law that epidemiology studies showing a causal

association are not required in Vaccine Act cases.

Petitioner has no obligation to provide statistical or epidemiological evidence. See, e.g.,

Capizzano, 440 F.3d at 1325-26. Additionally, a lack of supportive epidemiological evidence is

not dispositive. First, “epidemiological studies cannot absolutely refute a causal connection” and

“cannot prove a negative. It is always possible that another epidemiological study involving a

bigger population will detect an increased risk not otherwise apparent in smaller studies.” Harris

v. Sec’y of Health & Hum. Servs., No. 10-322V, 2014 WL 3159377, at *11 (Fed. Cl. Spec. Mstr.

June 10, 2014). Additionally, “[r]equiring epidemiologic studies . . . or general acceptance in the

scientific or medical communities . . . impermissibly raises a claimant’s burden under the

Vaccine Act and hinders the system created by Congress, in which close calls regarding

causation are resolved in favor of injured claimants.” Andreu, 569 F.3d at 1378 (quoting

Capizzano, 440 F.3d at 1325-26); see also Althen, 418 F.3d at 1280 (noting that “close calls” are

resolved in a petitioner’s favor).

Moreover, the conclusions reached in the published epidemiological studies cannot be

automatically extrapolated to the present case. Although the 2012 IOM report studied hearing

loss, the update in 2014 by Maglione et al. did not discuss hearing loss. The 2021 follow up

safety review by Gidengil et al. referenced the Baxter et al. epidemiological study. The Baxter et

al. study reported no cases of SSNHL within one week of the MMR vaccination. While Baxter

et al. also reviewed cases of SSNHL within 28 days of MMR vaccination, this data was only

included in the supplemental findings., which were not filed in the present case. Thus, it is

difficult to verify the study’s results as they related to the MMR vaccine.

Further, the Baxter et al. findings related to MMR do not identify the diagnosis in

question as AIED. Instead, the study focused on the broad umbrella of hearing loss cases, not

those specifically identified with an autoimmune etiology. Therefore, as observed by Petitioner,

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there does not appear to be an epidemiological study of AIED following the MMR vaccination.

See Pet. Reply at 4. Moreover, AIED appears to be an extremely rare condition which makes it

difficult to study.

Further, epidemiological studies have limited usefulness when the injury at issue is not

included in the study parameters. See, e.g., Moberly, 592 F.3d at 1324 (explaining

epidemiological studies “provide no evidence pertinent to persons not within the parameters of

the test group”); Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357, 1365 (Fed. Cir. 2000)

(“In order for [an epidemiological] study to be instructive, however, its conclusions must fit the

facts of the case under consideration.”).

Another argument against causation raised by Respondent is that the mechanism of

hearing loss caused by the wild-type of measles or mumps virus is not applicable because it

ignores the differences between immune responses to wild-type viruses and live attenuated

viruses. The differences in the natural infections and virus delivered in the form of vaccines is

acknowledged by the experts and in the medical literature. This acknowledgement does not

negate the reality that natural infections cause autoimmune diseases and that vaccines are also

associated with autoimmune diseases. The 2012 IOM committee noted that the wild-type

mumps virus infection was associated with deafness and the wild-type measles infection was

associated with bilateral “hearing loss in [five to 10] percent of measles cases.” Pet. Ex. 48 at

117. The committee “consider[ed] the effects of natural infection [as] one type of mechanistic

evidence.” Id.

Respondent’s arguments based on specific articles are also unavailing as the

undersigned’s decision does not turn on the findings of any one specific medical article. Overall,

the medical literature establishes that measles and mumps infections are associated with hearing

loss, that vaccines containing these live attenuated viruses have also been reported to cause

hearing loss, and that direct viral infection, molecular mimicry, and inflammatory responses have

been implicated as causal, with molecular mimicry being the favored theory for AIED.

The undersigned has adjudicated several SNHL, SSNHL, and hearing loss cases and did

not find the petitioners’ hearing loss was autoimmune, or that their hearing loss was caused by a

vaccine.

In Alsaadeh, the undersigned denied entitlement where Petitioner alleged the flu and

Prevnar 13 vaccines caused his hearing loss. Alsaadeh v. Sec’y of Health & Hum. Servs., No.

19-1097V, 2024 WL 694072 (Fed. Cl. Spec. Mstr. Jan. 23, 2024). The petitioner specifically

alleged his hearing loss was AIED, however, the undersigned found the petitioner had not

provided preponderant evidence for AIED. Id. at *30-31. In Herms, the undersigned also denied

entitlement where a petitioner alleged that the diphtheria-tetanus-acellular pertussis vaccination

that she received caused SNHL and tinnitus in her left ear. Herms v. Sec’y of Health & Hum.

Servs., No. 19-70V, 2024 WL 1340669, at *1 (Fed. Cl. Spec. Mstr. Mar. 4, 2024), mot. for rev.

den’d, aff’d, 173 Fed. Cl. 1, appeal docketed, No. 25-1007 (Fed. Cir. Sept. 27, 2024). Although

the petitioner’s experts put forward a theory based, in part, on autoimmunity, the petitioner

“failed to establish her hearing loss was autoimmune in nature.” Id. at *23.

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In Zikeli and Buen, the undersigned denied entitlement for a flu and SSNHL claim after

she analyzed a seven-step theory from Dr. Monsell and found it was not sound and reliable.

Zikeli v. Sec’y of Health & Hum. Servs., No. 20-564V, 2025 WL 2306208, at *28-32 (Fed. Cl.

Spec. Mstr. July 16, 2025); Buen v. Sec’y of Health & Hum. Servs., No. 21-1314V, 2025 WL

2938046 (Fed. Cl. Spec. Mstr. Sept. 17, 2025) (denying a flu/SSNHL case on the same grounds).

In Zikeli, the undersigned again found that the petitioner’s SSNHL was not consistent with

autoimmune hearing loss. Zikeli, 2025 WL 2306208, at *33 (“Petitioner’s hearing loss was

unilateral and acute. Autoimmune hearing loss typically affects both ears in a progressive

course.”).

Here, however, Petitioner was diagnosed with AIED by her treating physicians and both

parties’ experts agreed Petitioner’s diagnosis is an autoimmune hearing loss. Further, none of

the undersigned’s prior hearing loss denials involved an MMR vaccination.

In summary, Petitioner has shown by preponderant evidence that AIED is an autoimmune

form of hearing loss, that hearing loss can be caused by measles and mumps infections, and that

there are a number of case reports showing an association between hearing loss and measles and

mumps vaccinations. Medical literature shows that the favored casual theory for AIED is

molecular mimicry, although no antigenic trigger has been discovered, and the target of such

trigger in the inner ear is not yet known. For all of these reasons, the undersigned finds that the

weight of the evidence as to Althen prong one preponderates in Petitioner’s favor. Therefore,

Petitioner has provided preponderant evidence to satisfy prong one.

B. Althen Prong Two

Under Althen prong two, Petitioner must prove by a preponderance of the evidence that

there is a “logical sequence of cause and effect showing that the vaccination was the reason for

the injury.” Capizzano, 440 F.3d at 1324 (quoting Althen, 418 F.3d at 1278). “Petitioner must

show that the vaccine was the ‘but for’ cause of the harm . . . or in other words, that the vaccine

was the ‘reason for the injury.’” Pafford, 451 F.3d at 1356 (internal citations omitted).

In evaluating whether this prong is satisfied, the opinions and views of the vaccinee’s

treating physicians are entitled to some weight. Andreu, 569 F.3d at 1367; Capizzano, 440 F.3d

at 1326 (“[M]edical records and medical opinion testimony are favored in vaccine cases, as

treating physicians are likely to be in the best position to determine whether a ‘logical sequence

of cause and effect show[s] that the vaccination was the reason for the injury.’” (quoting Althen,

418 F.3d at 1280)). Medical records are generally viewed as trustworthy evidence since they are

created contemporaneously with the treatment of the vaccinee. Cucuras, 993 F.2d at 1528.

While the medical records and opinions of treating physicians must be considered, they are not

binding on the special master. § 13(b)(1)(B) (specifically stating that the “diagnosis, conclusion,

judgment, test result, report, or summary shall not be binding on the special master or court”).

A petitioner need not make a specific type of evidentiary showing, i.e., “epidemiologic

studies, rechallenge, the presence of pathological markers or genetic predisposition, or general

acceptance in the scientific or medical communities to establish a logical sequence of cause and

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effect.” Capizzano, 440 F.3d at 1325. Instead, Petitioner may satisfy her burden by presenting

circumstantial evidence and reliable medical opinions. Id. at 1325-26.

The undersigned finds that Petitioner has proven Althen prong two by preponderant

evidence for the following three reasons.

First, Petitioner’s diagnosis of AIED is an autoimmune condition, and the Petitioner has

shown that the theory of molecular mimicry is the likely causal mechanism. Her clinical course

was consistent with this autoimmune illness.

Respondent suggests that Petitioner’s clinical course was not consistent with MMR

vaccine-induced hearing loss for two reasons. First, Respondent argues that the eight cases

relied on by the 2012 IOM committee for the assessment of “low-intermediate” presented with

“fever, rash, and nystagmus,” whereas Petitioner did not these symptoms. Resp. Response at 17-

18. Petitioner did not report fever or rash. She did develop a “very slight horizontal nystagmus,”

as documented in the medical records. 85 Pet. Ex. 2 at 804. Notably, Respondent’s expert, Dr.

Ying, explained that not all patients experience these symptoms. Dr. Ying specifically opined

that “asymptomatic cases of mumps can also result in sudden SNHL.” Resp. Ex. C at 6. Since

Respondent’s expert expressly opined that some patients may be asymptomatic, Respondent’s

argument on this point is not well founded.

Again, related to clinical presentation, Respondent suggests that because Petitioner’s

MRI done in June 2019 was unremarkable, her course was inconsistent with vaccine causation.

Resp. Response at 31 (citing Resp. Ex. C at 8). In her expert report, Dr. Ying noted that

Petitioner’s MRI studies “did not show high signal intensity in the affected cochlea as reported

by Otake et al.” Resp. Ex. C at 8 (citing Pet. Ex. 45). Otake et al. described an asymptomatic

10-year-old child who had a 3D-FLAIR technique “applied” to his MRI which showed “high

signals in the right cochlea and vestibule . . . indicat[ing] hemorrhage or a high concentration of

protein.” Pet. Ex. 45 at 1. The authors suggested that the “3D-FLAIR MRI may help to identify

and define labyrinthitis in mumps deafness.” Id. The mechanism of hearing loss was thought to

be due to “direct viral invasion of the cochlea,” or direct infection, and not an autoimmune

mechanism. See id. at 2. Moreover, the point of the paper was to describe the 3D-FLAIR

technique and its ability to detect abnormalities of the inner ear in contrast to other MRI

protocols. 86 Finally, there is no question that Petitioner had labyrinthitis like the case reported

by Otake et al., even if it was not visualized on the MRI. See, e.g., Pet. Ex. 2 at 1300 (assessing

Petitioner with “bilateral labyrinthitis”).

The second reason for the undersigned’s ruling on prong two is because Petitioner’s

treating physicians questioned an association between her MMR vaccinations and the onset of

85

The undersigned acknowledges that Petitioner’s nystagmus was not documented in the

medical records until November 6, 2019.

86

Petitioner’s MRI done in June 2019 was performed using 3D FIESTA technique for the

internal auditory canals. See Pet. Ex. 2 at 1313-14. Dr. Ying did not opine as to the differences

or similarities between this MRI technique and the 3D FLAIR technique used in Otake et al.

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her AIED. In July 2019, Petitioner’s ENT, Dr. Kay, documented the following: “Had MMR

vaccine in [two] steps. [One to two] months before onset of symptoms. There are reports on the

literature of similar vaccines causation hearing loss and vestibular dysfunction . . . coincidental

vs possible causation-unclear”. Pet. Ex. 2 at 1134-38. In November 2019, Petitioner consulted

with Dr. Hain who wrote, “[r]egarding this picture arising post-vaccination (MMR), I have never

encountered this situation although I have seen about 300 patients with bilateral loss in my

career. It cannot be common.” Id. at 793.

While neither of these physicians opine that Petitioner’s AIED was caused by her MMR

vaccination, they both question vaccination as the causal trigger of Petitioner’s AIED. Treating

physician statements are “favored” evidence in support of Althen prong two. Capizzano, 440

F.3d at 1326. Further, statements from treating physicians that “do not amount to [an] opinion[]

on causation” may still provide “circumstantial evidence” in support of Althen prong two. Osso

v. Sec’y of Health & Hum. Servs., No. 18-575V, 2023 WL 5016473, at *2 (Fed. Cl. Spec. Mstr.

July 13, 2023). Here, both Dr. Kay and Dr. Hain note the temporal association of Petitioner’s

hearing loss with her vaccine. Dr. Kay acknowledges similar vaccine causation in the medical

literature. Neither doctor discounted vaccination as an etiology of Petitioner’s AIED. Instead,

Dr. Kay opined that it was “unclear” whether Petitioner’s MMR vaccine was “coincidental” or

causative, and Dr. Hain discussed the rarity of vaccine induced hearing loss. Pet. Ex. 2 at 1138.

While these statements from Petitioner’s treating physicians do not amount to an opinion on

causation, they provide circumstantial evidence that Petitioner’s treating physicians associated

her MMR vaccine with the development of her AIED.

The third reason for the undersigned’s finding on Althen prong two is that no alternative

cause for Petitioner’s hearing loss was found, although Petitioner had a very thorough work up

and saw many specialists in consultation for her AIED. Petitioner’s AIED was not secondary to

another autoimmune disease. Petitioner’s expert, Dr. Monsell ruled out several alternate causes

of SNHL such as age-related hearing loss, toxic noise exposure, ototoxicity, Meniere’s disease,

vestibular schwannoma, and stroke. He also explained that Petitioner’s clinical course was not

consistent with eustachian tube dysfunction associated with plane travel. While Dr. Ying

suggested that “stressors from vacation/traveling . . . could trigger immune response,” Dr. Ying

did not expand on this theory. Resp. Ex. C at 9.

While petitioners are not required to eliminate all alternative causes, the lack of

alternative cause “may be included as part of evidence to satisfy” Althen prong two. Ramsey v.

Sec’y of Health & Hum. Servs., No. 21-1486V, 2023 WL 2823403, at *6 (Fed. Cl. Spec. Mstr.

April 6, 2023); see also Walther v. Sec’y of Health & Hum. Servs., 485 F.3d 1146, 1151 (Fed.

Cir. 2007) (noting petitioners may use rely on “evidence eliminating other potential causes to

help carry the burden on causation”). Here, Petitioner’s evidence that no alternative cause was

found for her AIED provides additional support for her prong two showing.

Therefore, the undersigned finds Petitioner has proven Althen prong two by preponderant

evidence.

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C. Althen Prong Three

Althen prong three requires Petitioner to establish a “proximate temporal relationship”

between the vaccination and the injury alleged. Althen, 418 F.3d at 1281. That phrase has been

defined as a “medically acceptable temporal relationship.” Id. A petitioner must offer

“preponderant proof that the onset of symptoms occurred within a timeframe for which, given

the medical understanding of the disorder’s etiology, it is medically acceptable to infer

causation-in-fact.” de Bazan, 539 F.3d at 1352. The explanation for what is a medically

acceptable time frame must also coincide with the theory of how the relevant vaccine can cause

the injury alleged (under Althen prong one). Id.; Koehn v. Sec’y of Health & Hum. Servs., 773

F.3d 1579, 1243 (Fed. Cir. 2014); Shapiro, 101 Fed. Cl. at 542.

Petitioner received her first MMR vaccination on March 15, 2019, and her second MMR

vaccination on April 19, 2019. She presented for bilateral ear fullness on May 25, 2019, reported

onset of symptoms occurred four to five days before. Therefore, onset of symptoms began

approximately May 19 or 20, or 30 days after her second MMR vaccination.

Petitioner’s expert, Dr. Monsell, opined that this onset was consistent with an immune-

mediated response following her MMR vaccination. The time frame of four to six weeks is

consistent with case reports of hearing loss after MMR vaccination. The summary of cases by

Asatryan et al. showed that onset “ranged from [two] to 89 days following vaccination, with a

peak on days 10 through 14.” Pet. Ex. 16 at 3, 3 fig.1. Additional case reports illustrate an onset

of three weeks. For example, Rikitake et al. described bilateral acute hearing loss three weeks

following the mumps vaccine and Hulbert et al. reported bilateral hearing loss 22 days following

MMR vaccination.

Moreover, although Respondent’s expert immunologist Dr. Staats disagreed that the

MMR vaccination caused Petitioner’s hearing loss, he did not take issue with the onset time

frame. Dr. Staats acknowledged the temporal association between Petitioner’s vaccination and

AIED. Resp. Ex. A at 5 (“Other than a temporal association between the MMR vaccine and

[Petitioner’s] hearing loss, there is no compelling evidence.”). Dr. Ying opined that the onset

was too long to implicate hearing loss caused by infection, but she did not appear to refute the

opinion that 30 days would be appropriate for the theory of molecular mimicry.

Therefore, undersigned finds that Petitioner has met her burden of proof as to Althen

prong three.

V. CONCLUSION

Based on the record, and for the reasons discussed above, the undersigned finds there is

preponderant evidence to satisfy all three Althen prongs and to establish that Petitioner’s MMR

vaccination caused her to develop AIED. Therefore, the undersigned finds that Petitioner is

entitled to compensation.

A separate damages order will issue.

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IT IS SO ORDERED.

s/Nora Beth Dorsey

Nora Beth Dorsey

Special Master

46