LLOYD v. SECRETARY OF HEALTH AND HUMAN SERVICES

In the United States Court of Federal Claims

OFFICE OF SPECIAL MASTERS

No. 21-1332V

************************* Chief Special Master Corcoran

MARLENA and *

JEFFREY LLOYD, * Filed: September 29, 2025

as parents and natural guardians of C.L., *

a minor, *

*

Petitioners, *

*

v. *

*

SECRETARY OF HEALTH AND *

HUMAN SERVICES, *

*

Respondent. *

*

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

Ronald Homer, Conway Homer P.C., Boston, MA, for Petitioners.

Alec Saxe, U.S. Department of Justice, Washington, DC, for Respondent.

ENTITLEMENT DECISION 1

On May 6, 2021, Marlena and Jeffrey Lloyd, on behalf of their minor child, C.L., filed this

action seeking compensation under the National Vaccine Injury Compensation Program (the

“Vaccine Program”). 2 Petition (ECF No. 1) (“Pet.”) at 1. Petitioners alleged that C.L. developed

transverse myelitis (“TM”) due to the diphtheria/tetanus/acellular pertussis (“DTaP”),

haemophilus influenzae B (“Hib”), inactivated poliovirus (“IPV”), pneumococcal conjugate

(“PCV”), and rotavirus vaccines she received on October 7, 2020. Pet. at 1.

1

Under Vaccine Rule 18(b), each party has fourteen (14) days within which to request redaction “of any information

furnished by that party: (1) that is a trade secret or commercial or financial in substance and is privileged or

confidential; or (2) that includes medical files or similar files, the disclosure of which would constitute a clearly

unwarranted invasion of privacy.” Vaccine Rule 18(b). Otherwise, the whole Ruling will be available to the public in

its present form. Id.

2

The Vaccine Program comprises Part 2 of the National Childhood Vaccine Injury Act of 1986, Pub. L. No. 99-660,

100 State. 3758, codified as amended at 42 U.S.C. §§ 300aa-10 through 34 (2012) [hereinafter “Vaccine Act” or “the

Act”]. Individual section references will be to § 300aa of the Act (but will omit that statutory prefix).

A one-day entitlement hearing was held in Washington, D.C., on January 16, 2025. Now,

based upon my review of the record and consideration of the hearing testimony, including expert

input, I deny entitlement.

I. Fact Summary

Early Medical History and October 2020 Vaccinations

C.L. was born on June 7, 2020, following a pregnancy that was complicated by maternal

severe pre-eclampsia. Ex. 4 at 59. C.L.’s Apgar scores 3 were 8 and one minute and 9 at five

minutes. Id. She was seen by her pediatrician for routine well baby visits over the next several

weeks, and was noted to exhibit normal growth and development, despite experiencing some

abnormal weight loss, neonatal jaundice, and chronic eczema. See Ex. 5 at 15–16, 20–21, 23–25.

On August 19, 2020, Mrs. Lloyd took C.L. for a two-month check-up based upon concerns

that she was congested. Ex. 5 at 17. At that time, C.L. also received the DTaP, Hib, IPV, PCV,

Hepatitis B (“Hep B”), and rotavirus vaccines—all without complication. Id. at 17–19. There were

no abnormal findings documented during C.L.’s assessment at this time. Id. at 18–19. Two months

later, on October 7, 2020, C.L. received her second doses of the DTaP, Hib, IPV, PCV, and rotavirus

vaccines—again without complication or any evidence of an immediate reaction. She was further

noted to be generally well developed, well nourished, and in no apparent distress. Id. at 13–14.

Hospitalization from Late-October 2020 to March 2021

On October 26, 2020 (now nineteen days after the vaccinations at issue), Mrs. Lloyd took

C.L. to her pediatrician’s office due to symptoms of irritability and fussiness that had begun while

at daycare around noon that same day. Id. at 10. Mrs. Lloyd reported that C.L. had refused to take

her bottle and was not moving much. Ex. 5 at 10. She further noted that C.L. had appeared normal

prior to being dropped off at daycare, but stated that there were similarly ill contacts at C.L.’s

daycare, and even indicated that she and Mr. Lloyd were then experiencing upper respiratory

infections (“URIs”). Id.

Upon examination, C.L. appeared “severely ill, crying, and lethargic.” Ex. 5 at 10. Her

anterior fontanel was sunken, and her nose was congested. Id. Sara Dorsey, the examining nurse

practitioner, advised Mrs. Lloyd to take C.L. directly to the emergency room (“ER”) at Children’s

Healthcare of Atlanta Emergency Department for further evaluation. Id.

At the hospital, Petitioners explained to treating staff that C.L. had been in her usual state

of health (except mild nasal congestion) up until a few hours before. Ex. 6 at 632. They also noted

3

“Apgar Score” is defined as “a numerical expression of the condition of a newborn infant, usually determined at 60

seconds after birth, being the sum of points gained on assessment of the heart rate, respiratory effort, muscle tone,

reflex irritability, and color.” Apgar Score, Dorland’s Medical Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=105165&searchterm=Apgar+score (last visited Sep. 24,

2025).

2

that their entire family (including C.L.) had been sick with URI symptoms in the previous month.

Id. Upon examination, C.L. was characterized as not wanting to move or use her arms, not gripping

Mrs. Lloyd’s finger, and not wanting to put any weight on her legs. Id. at 1069. Mrs. Lloyd reported

to the emergency medicine physician, Phillip Kelley, M.D., that C.L. exhibited no fever, cough, or

cold symptoms, and experienced no vomiting or diarrhea. Id.

Upon examination, C.L.’s upper extremities were documented as “motionless and [she]

[did] not respond to pinching of the medial aspect of [her] upper arm . . .” Ex. 6 at 1070. Dr. Kelley

further noted an apparent “anesthetic area superior to the horizontal line at 2 cm inferior to the

nipples above which [C.L.] show[ed] no response” but that “below this line[,] [C.L.] [could] move

[her] legs when pinched.” Id. Although C.L. exhibited bilateral deep tendon reflexes (“DTRs”),

she had no grip strength and could not be pulled to sit as she had no muscle tone. Id. Lab results

at this time were unremarkable. Id. at 1074.

C.L. was next seen by neurologist Stephanie Keller, M.D. Ex. 6 at 1074. Dr. Keller

documented C.L.’s ability to lift both legs from the hip and kick, but noted no movement in her

arms or hands. Id. at 863. Dr. Keller also noted that C.L. withdrew from pain in the trunk above

T4 ,and in the legs and lower extremities, but did not withdraw from pain in her arms. Id. Similarly,

Dr. Keller was able to elicit DTRs in C.L.’s bilateral patella, but was unable to elicit the same

response in her upper extremities. Id. Dr. Keller’s notes indicated a “concern[ ] for a cervical or

upper thoracic spine process,” and recommended C.L. undergo X-rays of her neck to rule out a

bone injury before undergoing MRIs of her brain and complete spin. Id. at 863, 1074. C.L.’s X-

rays of her cervical spine were unremarkable, but brain and spine MRIs revealed “[n]onenhancing

expansile cord signal abnormality extending from C2 to T5.” Id. at 1073–74.

A second neurologist, David Wolf, M.D., read C.L.’s MRIs as revealing “multisegmental

T2/FLAIR hyperintense lesion in [the] cervical spine,” which he found concerning for TM. Ex. 6

at 1076. Dr. Wolf recommended C.L. undergo a lumbar puncture (“LP”) so as to rule out other

potential causes before having C.L. transferred to the Pediatric Intensive Care Unit (“PICU”) for

a single dose of high dose corticosteroid therapy. Id. at 1068, 1074, 1076. Following performance

of the LP, C.L. was admitted to the PICU for close neurologic monitoring and critical care

management. Id. at 632–41. Upon admission, C.L. was hypertensive, motionless in her upper

extremities, and had no head control. Id. at 633. She was also unresponsive to painful stimuli above

the nipple line, had mildly labored breathing, as well as required a c-collar due to minimal head

control. Id. at 635.

On the morning of October 27, 2020, C.L. had difficulty breathing, leading attending

physician Charlene Banks, M.D., to intubate her. Ex. 6 at 1076. She was again examined by Dr.

Keller, who noted “some progression of [C.L.’s] weakness [ ] and loss of her reflexes.” Id. at 1088.

Dr. Keller’s notes included rhinovirus and adenovirus among C.L.’s active problems, as well as

3

her concern for Acute Flaccid Myelitis (“AFM”) 4 based on C.L.’s positive viral panel. Id. at 1088.

Follow-up cervical and thoracic spine MRIs were ordered to determine whether there was more

gray or white matter involvement—the results of which demonstrated “[p]redominately gray

matter involvement” and “extension of the spinal cord lesion but . . . no restricted diffusion—

proving to be more “consistent with probable AFM”, according to Dr. Keller. Id. C.L.’s steroid

treatment was subsequently stopped, and she began a two-day IVIG 5 course. Id. at 1076.

C.L.’s medical management team then consulted with infectious disease specialist,

Christina Rostad, M.D. Ex. 6 at 684–72. During the consultation, Dr. Rostad noted that C.L. had

exhibited several days of “URI [symptoms] and [a] low grade fever (99.4F) leading up to the

changes in her clinical status on Monday[,] 10/26” and further confirmed that C.L.’s Respiratory

Viral Panel (“RVP”) was positive for rhino/enterovirus and adenovirus. Id. at 864, 872. Dr. Rostad

agreed with C.L. neurology team that C.L. should continue treating with IVIG. Id. at 872.

Over the next two days (October 29 – 30, 2020), C.L. developed intermittent fevers. Ex. 6

at 1132. Dr. Rostad suggested that the fevers “[m]ay have been attributable to her known viral

infections vs. IVIG infusion, or an occult bacterial process.” Id. She agreed to continue monitoring

C.L. to see whether her “presentation evolve[d] into transverse myelitis.” Id. at 1118. C.L.

underwent chest X-rays on October 31, 2020, which revealed “[p]ersistent multifocal airspace and

alveolar opacities concerning for pulmonary edema vs infectious process.” Id. at 1132. Due to the

concern for development of a secondary bacterial infection, Dr. Rostad recommended C.L. begin

an antimicrobial therapy with ceftazidime. Id.

On November 2, 2020, C.L. underwent repeat MRIs of her total spine, which revealed

“[p]ersistent T2 high signal abnormality [of] the cervical and thoracic cord, improved when

compared with [her] prior study” and “[p]ersistent widening of the cervical cord”—suggesting

further a concern for AFM. Ex. 6 at 1253. At this time, she remained intubated and mechanically

4

“Acute Flaccid Myelitis” is defined as “an uncommon but serious neurologic condition” which “affects the nervous

system, specifically the area of the spinal cord called gray matter, which causes the muscles and reflexes in the body

to become weak.” About Acute Flaccid Myelitis, Center for Disease Control, https://www.cdc.gov/acute-flaccid-

myelitis/about/index.html (last visited Sep. 29, 2025).

5

“Intravenous Immunoglobulin” is defined as “a pooled anti body, and a biological agent used to manage various

immunodeficiency states and a plethora of other conditions, including autoimmune, infectious, and inflammatory

states. The ultimate goal of this therapy is to normalize a compromised immune system.” Intravenous Immunoglobulin

(IVIG), National Library of Medicine, https://www.ncbi.nlm.nih.gov/books/NBK554446/ (last visited Sep. 29, 2025).

4

ventilated. Id. at 1187. She underwent NCS 6 and EMG 7 studies six days later, on November 8,

2020, but the results were unremarkable. Id. at 1352.

C.L. was eventually started on a new, high-dose steroid course due to the swelling of her

cervical cord. Ex. 6 at 1352, 1384. After four days of a five-day treatment course, C.L. showed

mild improvement—leading her neurologist Sumit Verna, M.D., to recommend weaning C.L. off

the high-dose steroid course and following it with an oral steroid following completion of her fifth

and final day of treatment. Id. at 1384. C.L. was to undergo a second round of IVIG the following

week. Id.

On November 17, 2020, C.L. was extubated. Ex. 6 at 1474. Records indicate that C.L.

could spontaneously mover her arms as well as her lower extremities to minimal stimuli. It was

further noted that she had increased tone in her lower extremities and slightly increased ton in her

right upper extremity. Id. at 1474–75. Neurologist Amber Auad, M.D., examined C.L. the next day

and noted she could bring both hands to her mouth, swat but not grasp, and move her lower

extremities minimally with stimulation. Id. at 1503–04. Dr. Auad opined that TM was the most

likely diagnosis, although C.L. would need to be followed over time before it could be confirmed.

Ex. 6 at 1508.

A repeat MRI of C.L.’s spine performed on November 20, 2020, revealed “[p]ersistent

abnormal contrast enhancement of the cauda equina nerve roots.” Ex. 6 at 1616. C.L. began

exhibiting improvement in her functioning following a tracheostomy placement on December 1,

2020. Id. at 282. C.L.’s father noted that she was able to open and close her right hand and

spontaneously move the fingers of her left hand and her toes. Id. at 1793. It was further noted that

C.L. no longer needed a catheter, as she was able to urinate on her own. Id.

C.L. was eventually transferred out of the PICU and into the Comprehensive Inpatient

Rehabilitation Unit (“CIRU”) on December 9, 2020. Ex. 6 at 461, 475. C.L. remained in the CIRU

until she was discharged in March 2021. Id. During the remainder of her hospitalization, C.L.

received her monthly doses of IVIG treatment, and demonstrated cognitive and linguistic skills,

hearing, and comprehension of basic information within functional limits. Id. at 619, 2096, 2521,

4011. C.L. was discharged on March 1, 2021, and further noted to have met her long-term goals

6

“Nerve Conduction Study” is defined as “an essential tool in the evaluation of the peripheral nervous system. The

sensory nerve action potential (SNAP) provides information on the sensory nerve axon and its pathway from the distal

receptors in the skin to the dorsal root ganglia, while the compound muscle action potential (CMAP) is an assessment

of the motor nerve fibers from their origins in the anterior horn cell to their termination along muscle fibers.” Nerve

Conduction Studies: Basic Concepts, National Library of Medicine, https://pubmed.ncbi.nlm.nih.gov/31277849/ (last

visited Sep. 29, 2025).

7

“Electromyography” is defined as “an electrodiagnostic technique for recording the extracellular activity (action

potentials and evoked potentials) of skeletal muscles at rest, during voluntary contractions, and during electrical

stimulation; performed using any of a variety of surface electrodes, needle electrodes, and devices for amplifying,

transmitting, and recording the signals.” Electromyography, Dorland’s Medical Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=15854&searchterm=electromyography (last visited Sep. 24,

2025).

5

established during her initial physical therapy evaluation. Id. at 4021. C.L. treating physicians

recommended she continue with occupational and physical therapy following her discharge. Id.

Treatment Course Post-Hospitalization

On June 9, 2021, C.L. saw neurologist Grace Gombolay, M.D. Ex. 12 at 2515–23. She

noted C.L. was “continuing to make progress . . . eating by mouth now, and [ ] [ ] army crawling,”

as well as exhibiting some improvement in her posture and return of sensation to her legs. Id. Dr.

Gombolay, however, documented that C.L. still had clonus. 8 Id. C.L. was to start weaning off

gabapentin begin a three-month trial of IVIG, obtain repeat spine MRIs, and follow-up in four

months. Id. at 2522. A little over a month later, C.L. was admitted to Children’s Healthcare of

Atlanta on July 23, 2021, for ventilator weaning and was discharged two days later. Ex. 54 at 65.

C.L. underwent repeat spine MRIs on January 26, 2022, which demonstrated “[n]o definite

residual spinal cord signal abnormality,” and “[r]esolution of previously seen contrast

enhancement of the cauda equina nerve roots.” Ex. 12 at 7806. C.L. saw Dr. Gombolay regularly

for neurology follow-up visits, and was deemed to be doing well overall and making continued

improvements. Ex. 13 at 2994 (October 2022 visit). Dr. Gombolay diagnosed C.L. with TM and

cross-eye after observing some abnormal eye movements upon examination. Id. at 3002.

Throughout her post-hospitalization treatment course, C.L.’s medical records indicate that she

continued to gradually receive additional various childhood vaccines, although her recovery has

not been complete. Id. at 9886; Ex. 54 at 85.

II. Expert Testimony

A. Petitioners’ Expert - Daniel J. Bonthius, M.D., Ph.D.

Dr. Bonthius, a neurologist, submitted three written reports on behalf of Petitioner and

testified at the hearing. Report, dated May 31, 2023, filed as Ex. 14 (ECF No. 40-1); Report, dated

March 25, 2024, filed as Ex. 70 (ECF No. 53-1); Report, dated September 26, 2024, filed as Ex.

89 (ECF No. 60-1). Dr. Bonthius opined that one or more of the vaccines C.L. received in October

2022 could cause acute TM, and did so to C.L.

Dr. Bonthius obtained his B.S. in Zoology, and M.D., and Ph.D. in neuroscience, all from

the University of Iowa. See Curriculum Vitae, filed as Ex. 15 (ECF No. 40-2) (“Bonthius CV”).

After obtaining his joint M.D. and Ph.D., Dr. Bonthius accepted a Fulbright Scholarship at the

University of Otago, in New Zealand, where he conducted research in Neuroanatomy. Bonthius

CV at 1. From there, he completed a post-doctoral fellowship in Neuroscience and residency in

8

“Clonus” is defined as “1. Alternate muscular contraction and relaxation in rapid succession. 2. A continuous

rhythmic reflex tremor initiated by the spinal cord below an area of a spinal cord injury, set in motion by reflex

testing.” Clonus, Dorland’s Medical Dictionary Online,

https://www.dorlandsonline.com/dorland/definition?id=10153&searchterm=clonus (last visited Sep. 24, 2025).

6

Pediatrics at the University of Virginia. Id. He then completed a second residency in Pediatric

Neurology at the University of Iowa, where he was offered a faculty position and practiced as a

pediatric neurologist for twenty-two years. Id. Dr. Bonthius is board certified in Neurology with a

Special Qualification in Child Neurology, and is licensed to practice medicine in the state of North

Carolina. Id. He currently serves as the Division Chief for the Division of Child Neurology at

Atrium Health/Levine Children’s Hospital in Charlotte, North Carolina, and teaches Neurology at

Wake Forest University School of Medicine. Id. at 2. In addition, he has published literature on

immune-mediated injury to the central nervous system and has around 71 peer-reviewed

publications. Id. at 23–29.

Dr. Bonthius defined TM as an acute onset, inflammatory disease localized to the spinal

cord. Tr. at 24:11–13. Symptoms include weakness of the extremities, sensory loss, and

impairment of bladder function. Id. at 24:15–17. Diagnostic criteria for TM include many factors,

but in Dr. Bonthius’s opinion “sensory motor or autonomic dysfunction attributable to the spinal

cord, T2 hyperintense signal changes on the spinal MRI, and no evidence of a compressive cord

lesion” are “probably necessary” for the diagnosis to be correct. Id. at 25–26; B. Greenberg,

Transverse Myelitis, UpToDate (2023), http://www.UpToDate.com, filed as Ex. 27 (ECF No. 40-

14) (“Greenberg”). After recounting C.L.’s medical history, Dr. Bonthius agreed with the hospital

physician’s diagnosis of TM, and deemed it consistent with accepted criteria for the condition. Id.

at 12, 26–27.

Dr. Bonthius opined that the cause of C.L.’s TM was either one or a combination of her

four-month vaccines received in October 2020. Tr. at 27. To support the relationship between

vaccines and TM, Dr. Bonthius primarily relied on three articles. See id. at 29–31 (discussing F.

Pidcock et al., Acute Transverse Myelitis in Childhood: Center-Based Analysis of 47 Cases, 68

Neurology 1474, 1479 (May 1, 2007), filed as Ex. 42 (ECF No. 40-29) (“Pidcock”) (twenty-eight

percent of patients reviewed developed TM within thirty days of receiving a vaccine); A. Kaplin

et al., Diagnosis and Management of Acute Myelopathies, 11 Neurologist 1, 4 (2005), filed as Ex.

31 (ECF No. 40-18) (“Kaplin”) (discussing immunopathogenesis and putative mechanisms for the

development of TM in patients); A. Borchers et. al., Transverse Myelitis, 11 Autoimmunity Revs.

231, 241–42 (2012), filed as Ex. 103 (ECF No. 73-3) (“Borchers”) (listing multiple potential

triggers for TM).

The correlation between TM and vaccines is widely noted, even if complete evidence of

causation is still lacking. See generally Kaplin; Pidcock. Thus, Kaplin’s authors observed that TM

as a post-vaccination event is widely reported in neurology texts despite a lack of sufficient

evidence of causation. Tr. at 30–31 (discussing Kaplin at 4). As a result, the exact mechanism by

which infections and immunizations trigger TM is unknown. Id. at 32, 53. But, Dr. Bonthius noted,

TM can be autoimmune or parasitic in origin. Id. at 27.

7

In instances where TM has an autoimmune-mediated pathology, Dr. Bonthius contended,

onset of the disease process could be triggered by many different factors, including prior or

ongoing infections, genetic susceptibility, or vaccines—in each case via the mechanism of

molecular mimicry. Tr. at 27–29, 32. Molecular mimicry is based upon the concept that a foreign

pathogen or antigen has an identical or similar sequence homology to a host protein, leading to

immune cross-reactivity by antibodies produced in response to the foreign, mimicking antigen. Id.

at 32; Kaplin at 4. It is a recognized immunopathogenic mechanism in some kinds of post-

vaccination central nervous system (“CNS”) demyelinating diseases. Tr. at 33–34 (citing N.

Agmon-Levin et al., Transverse Myelitis and Vaccines: A Multi-Analysis, 18 Lupus 1198, 1201

(Nov. 2009), filed as Ex. 16 (ECF No. 40-3) (“Agmon-Levin”) (authors assuming that because

infectious agents can induce autoimmunity, so can live, attenuated antigens used in vaccines); D.

Karussis & P. Petrou, The Spectrum of Post-Vaccination Inflammatory CNS Demyelinating

Syndromes, 13 Autoimmune Rev. 215, 221 (Mar. 2014), filed as Ex. 33 (ECF No. 40-20)

(“Karussis”). Kaplin’s authors found evidence of autoimmune disorders causing CNS dysfunction

in the spinal cords of post-vaccination patients that later died of TM. Id. at 34–35 (discussing

Kaplin at 3).

Antibodies are key to driving the cross-reactive harm that manifests as TM, Dr. Bonthius

contended. Tr. at 51–54 (referencing L. Pandit & S. Rao, Recurrent Myelitis, 60 J. Neurol.

Neurosurg. Psych. 336, 336 (1996), filed as Ex. 41 (ECF No. 40-28) (“Pandit”); D. Tippett et al.,

Relapsing Transverse Myelitis, 41 Neurology 703, 703 (1991), filed as Ex. 49 (ECF No. 40-49)

(“Tippett”); see also Greenberg). But Dr. Bonthius was unable to submit evidence showing

isolated antibodies from patients with idiopathic TM. Id. at 51–54. In addition, Dr. Bonthius did

not attempt to identify sequence or structural homology between the antigens or other components

in the vaccines C.L. received and human nerve components that would support the hypothesis that

they have molecular similarity. Id. at 63–65. He also conceded that the current state of modern

medicine does not allow for the conclusion that the DTaP, Hib, IPV, Prevnar or rotavirus vaccines

do cause TM in this manner, despite the reasoned evidence he believed supported this conclusion.

Id. at 55–56.

Instead, Dr. Bonthius’s molecular mimicry theory heavily relied on two analogies. First,

he analogized vaccines to infectious agents, concluding that because infectious agents can induce

autoimmunity, so can the live or attenuated antigens used in vaccines. Tr. at 57–58. Second, Dr.

Bonthius compared other autoimmune diseases to TM, stating that if they can be caused by

vaccines, TM could be as well. Id. at 61–63. Thus, her referenced neurologic conditions like

Guillain-Barré syndrome (“GBS”), Opsoclonus/myoclonus syndrome, and acute hemorrhagic

leukoencephalitis, all of which may be triggered by vaccination Id. (referencing H. Willison et al.,

Guillain-Barre Syndrome, 338 Lancet 717, (2016), filed as Ex. 52 (ECF No. 40-39); D. Koelman

& F. Mateen, Acute Disseminated Encephalomyelitis: Current Controversies in Diagnosis and

Outcome, 262 J. Neurol. 2013, (2015), filed as Ex. 34 (ECF No. 40-21); A. Piquet et al.,

8

Opsoclonus-Myoclonus Syndrome Post-Vaccination and Viral Illness, 3 Int. J. Clin. Med. 304,

(2012), filed as Ex. 43 (ECF No. 40-30); K. Wellnitz et al., Fatal Acute Hemorrhagic

Leukoencephalitis Following Immunization Against Human Papillomavirus in a 14 Year Old Boy,

Child Neurol. Open 2021, at 1, 4, filed as Ex. 50 (ECF No. 40-37)).

Dr. Bonthius next addressed the timing for post-vaccination onset. Tr. at 38–39. An

autoimmune response following a vaccine, he maintained, takes time before clinical manifestations

appear that would reflect the ongoing, cross-reactive damage. Id. at 38. Dr. Bonthius’s estimation

for peak immune response leading to onset of demyelinating diseases post-vaccination would be

between two to four weeks following the triggering event. Id. at 38–39. C.L.’s vaccines were

administered nineteen days before Petitioners observed her initial symptoms, placing them within

this post-vaccination window. Id. at 39. Therefore, in Dr. Bonthius’s opinion, C.L.’s TM onset and

immunizations line up with medical professionals’ expectations of a vaccine induced immune

response. Id.

Multiple case studies and other medical literature in this case, Dr. Bonthius contended,

demonstrate a comparable temporal relationship between administration of vaccines and the

development of TM or other autoimmune diseases. In one such case study, a seven-month old boy

was diagnosed with acute TM seventeen days after receiving a DTaP vaccine, consistent with the

timing in this case. R. Riel Romero, Acute Transverse Myelitis in a 7-month-old Boy After

Diphtheria-Tetanus-Pertussis Immunization, 44 Spinal Cord 688, 688 (Nov. 2006) (“Riel

Romero”). Another case report focused on the development of TM in a seven-month old girl only

six to seven days after receiving immunizations containing diphtheria, tetanus toxoid, and oral

poliomyelitis. E. Whittle & N. Robertson, Transverse Myelitis After Diphtheria, Tetanus, and

Polio Immunisation, 1 Brit. Med. J. 1450, 1450 (June 4, 1997) (“Whittle & Robinson”). The

authors of the Whittle & Robinson case study relied on the evidence of a temporal association for

a possible connection between the patient’s vaccines and her TM. Id. Other case reports and

medical literature offer similar observations and note the temporal correlation. See Tr. at 67–69

(discussing Karussis (inferred vaccine causation of TM based on case reports with temporal

association) and Agmon-Levin (noting the temporal association between vaccines and TM, and

stating this phenomenon cannot be ignored)).

Dr. Bonthius agreed that the authors of these case reports and other medical literature

usually acknowledged that it was unwise to give great weight to case reports and finding causation

based on temporal proximity. Tr. at 68 (quoting Kaplin at 3). Temporally-based findings must be

viewed with caution because the closeness of two events in time could be purely coincidental. Id.

at 68–69. Nevertheless, Dr. Bonthius considered the close proximity of the vaccines to C.L.’s TM

onset to be significant.

9

Dr. Bonthius also expressed the belief that a preexisting infection had not triggered C.L.’s

TM, contrary to what other providers seem to have believed. Tr. at 40–41, 83–84. In so opining,

he relied heavily on the fact that the vaccines C.L. received were administered closer in time to

her TM onset than the development of her infections. See id. at 80, 108. Yet he also contended that

the adenovirus and rhinovirus/enterovirus positive RVP panels performed around the time of C.L’s

hospitalization (and hence observed even closer in time to her onset) did not undermine his theory.

In so opining, he proposed that that C.L. had already likely recovered from her infections before

being admitted to the hospital. Id. at 17–18, 40. RVP tests can be positive even after the virus is

no longer active due to remnant nucleic acids from the virus remaining after infection. Id. at 39–

40. Accordingly, Dr. Bonthius did not deem these test results to establish the presence of live,

active viruses, but rather reflected a resolved prior infection. Id. at 18, 39–40. And C.L.’s treating

providers did not voice an opinion as to whether her RVP tests were indicative of a past or active

infection. Id. at 83–84.

At most, Dr. Bonthius contended, C.L.’s infections may have impacted her immune system

in a way that made her more vulnerable to an abnormal immune response brought on after the

October 2020 vaccinations. Tr. at 41. He offered independent medical literature as support for the

concept that exposure to multiple immune stressors can prompt abnormal immune responses. Id.

at 42 (citing G. Goldman & N. Miller, Relative Trends in Hospitalizations and Mortality Among

Infants by the Number of Vaccine Doses and Age, Based on the Vaccine Adverse Event Reporting

System (VAERS), 31 Hum. & Experimental Toxicology 1012, 1012 (2012), filed as Ex. 102 (ECF

No. 73-2) (“Goldman & Miller”).

Goldman & Miller discusses a Centers for Disease Control (“CDC”) report that indicates

exposures to mixed stressors can produce health consequences. See Goldman & Miller at 1018.

The possibility of concomitant exposure and increased risks of adverse effects is also noted as a

possibility by the authors of the Riel Romero case study as to why the patient developed TM. Tr.

at 35–36 (discussing Riel Romero at 690). The Riel-Romero patient was noted to have been

experiencing an infection at the time of receiving a tetanus-containing vaccine, which could have

been a complicating factor capable of stressing his immune system to the point where he developed

TM. Riel Romero at 690. The fact that C.L. received five vaccinations in the context of a prior

infection was thus significant to Dr. Bonthius, since this combination of stressors might have

overwhelmed C.L’s immune system, encouraging the development of TM. Tr. at 42–43.

B. Respondent’s Expert - Matthew J. Elrick, M.D. Ph.D.

Dr. Elrick, a neurologist, submitted two written reports on behalf of Respondent and

testified at the hearing. Report, dated September 10, 2023, filed as Ex. A (ECF No. 46-1) (“Elrick

First Rep.”); and Report, dated July 31, 2024, filed as Ex. C (ECF No. 57-1). Dr. Elrick opined

that that there was no evidence to support an antibody-mediated cause for TM, and he denied that

10

any of the vaccines C.L. received, alone or in combination, could have triggered C.L.’s TM. Elrick

First Rep. at 5.

Dr. Elrick obtained his Bachelor of Science in biochemistry from the University of

Maryland. See Curriculum Vitae, filed as Ex. B (ECF No. 43-20) (“Elrick CV”). From there, he

attended the University of Michigan, where he received his M.D. and Ph.D. in neurology. Elrick

CV at 1. Dr. Elrick then attended Johns Hopkins for his residencies in pediatrics and child

neurology. Id. Currently, Dr. Elrick is an Assistant Professor of Neurology and Developmental

Medicine at the Kennedy Krieger Institute and Assistant Professor of Pediatric Neurology and

Neuromuscular Medicine at the Johns Hopkins School of Medicine. Id. He is board certified in

Neurology with Special Qualification in Child Neurology, and he specializes in pediatric

neuromuscular disorders. Id. at 4. His practice has allowed him to frequently evaluate children

with transverse myelitis, spinal cord infarction, GBS, acute flaccid myelitis (AFM), infantile

botulism, myopathies, and myasthenia gravis. Elrick First Rep. at 1. Beyond practicing medicine,

Dr. Elrick has authored 19 peer-reviewed publications, some of which focus on the diagnosis of

AFM. Id.

Dr. Elrick made it clear from the outset of his testimony that he agreed with the Petitioner’s

TM diagnosis. Tr. at 118:13–16, 139–140. TM, he maintained, is historically a catch-all term for

several different kinds of CNS-oriented inflammatory disorders, many of which are not well-

understood. Id. at 121–22. But as medical science has developed, treaters have been better able to

identify, and differentiate, several specific disorders that in the past would have been grouped

under the general TM umbrella. Id. at 119–23. Here, Petitioner’s antibody testing, MRIs, observed

bilateral sensory dysfunction, and acute presentation (roughly twenty-four hours from onset to

nadir) ruled out many other demyelinating disorders, or AFM, in favor of the diagnosis of

idiopathic TM. See id. at 119–126.

Despite this agreement, Dr. Elrick disputed Dr. Bonthius’s causation theory. To the extent

vaccines have any association with TM, he maintained, it is due to instances in which there appears

a temporal association only, and more evidence is needed before a causal relationship can be

deemed likely. Tr. at 123–24 (discussing C. Krishnan et al., Transverse Myelitis: Pathogenesis,

Diagnosis and Treatment, 9 Frontiers in Bioscience 1483, 1483 (May 1, 2004), filed as Ex. A-9

(ECF No. 43-10) (“Krishnan”). Even many of Petitioner’s articles conceded this. Whittle &

Robertson at 1450; Riel-Romero at 690; Agmon-Levin at 1202.

Dr. Elrick summarized Dr. Bonthius’s medical theory as TM being caused by vaccines via

molecular mimicry, inducing an antibody response that results in immune cross-reactivity. Tr. at

126. But Dr. Elrick took issue with the contention that TM is likely an antibody-mediated disease.

Id. at 127. In his view, there is no more than scant evidence that autoantibodies are present in

idiopathic TM, and there is no evidence that they play a mechanistic role in causing it. Id. at 126–

11

27. This is in contrast to CNS-impacting autoimmune diseases known to be antibody-mediated,

like neuromyelitis optica and encephalomyelitis—where specific, identified antibodies are known

to exist and to likely drive the disease process. Id. 127–29 (discussing M. Kinoshita et al.,

Neuromyelitis Optica: Passive Transfer to Rats by Human Immunoglobulin, 386 Biochemical

Biophysical Rsch. Commc’ns 623, 623 (2009), filed as Ex. A-8 (ECF No. 43-9); H. Schluesener

et al., A Monoclonal Antibody Against a Myelin Oligodendrocyte Glycoprotein Induces Relapses

and Demyelination in Central Nervous System Autoimmune Disease, 139 J. Immunology 4016,

4016 (Dec. 15, 1987), filed as Ex. A-16 (ECF No. 43-17)).

Here, by contrast, Dr. Bonthius’s articles offered to support his claim that TM was an

antibody-mediated disorder either did not identify a causal autoantibody, or did not discuss testing

revealing the presence of one. Tr. at 129–30 (citing Pandit; Tippett). Only Greenberg provided

evidence of antibodies in a patient with TM, but that could be explained by the patient’s pre-

existing antiphospholipid antibody syndrome that had developed before TM. Id. at 130 (discussing

Greenberg). C.L. otherwise did not test positive for any particular antibodies that might be

biomarkers for any known CNS-oriented disease. Ex. 6 at 926; Tr. at 123. And Dr. Bonthius did

not propose a specific mimic between vaccine antigenic component and self nerve tissue, nor did

he establish evidence of structural or sequential homology for either. Tr. at 136–37.

Dr. Elrick also deemed flawed Dr. Bonthius’s argument that the existence of infectious

causes for TM (mediated by molecular mimicry) opened the door to vaccination causation. Tr. at

134 (“it’s not necessarily true that if an infection can cause an autoimmune disorder, that a

vaccination against the same infection will have the same immune response and the same

propensity for causing autoimmune disease”). In fact, Dr. Elrick could not think of any known

examples of molecular mimicry occurring due to receipt of a vaccine. Id. And he offered

independent evidence demonstrating that a response to a vaccination was not equivalent in relevant

respects to the immune response to a wild infection. Id. 134–36 (discussing M. Samanovic et al.,

Vaccine-Acquired SARS-CoV-2 Immunity versus Infection-Acquired Immunity: A Comparison of

Three COVID-19 Vaccines, 10 Vaccines 2152, 2152 (2022), filed as Ex. A-15 (ECF No. 81-15)

(reviewing differences in immune response between people who were vaccinated against SARS-

CoV-2 and those who were naturally infected by it).

Besides taking issue with Dr. Bonthius’s causation theory, Dr. Elrick argued that it could

not be concluded on this record that C.L.’s TM was caused by her October vaccinations. Rather,

there were two more-likely triggers for Petitioner’s TM: that it was truly idiopathic (meaning it

had no identifiable cause), or was caused by an antecedent infection (adenovirus and/or

rhino/enterovirus). Tr. at 157-58, 170, 190.

A disease is deemed idiopathic if there is no understood explanation of its cause. Tr. at 76.

Idiopathic transverse myelitis lacks a known pathogenic mechanism, and in fact may not be caused

12

by autoantibodies at all. Id. at 53. At best, there has been an observed correlation where 30% to

60% of idiopathic TM cases have an antecedent respiratory, gastrointestinal, or systemic illness.

See id. at 77–78, 158; see also Greenberg at 2; Krishnan at 1491. And even so, Dr. Elrick noted,

roughly half of idiopathic TM cases have no identifiable triggers or preceding environmental

factor—vaccine, injury, or infection—that could even be possibly causal. Id. at 158.

Here, however, the medical record did identify several possible triggers: an adenovirus

infection, rhino/enterovirus infection, or a combination of the two. See Tr. at 155. Medical science

accepts that TM can be post- or para-infectious, and has documented the frequency and kinds of

infections preceding TM diagnoses. Id.; Greenberg at 2; Krishnan at 1491. Krishnan’s authors

have in fact noted that many cases of TM are post-infectious. Krishnan at 1944. And another article

expressly identifies adenovirus and enterovirus as infections that may be associated with

myelopathies (which would also include TM). Tr. at 124–25; J. Lyons et al., Myelopathy

Associated with Microorganisms, 21 Continuum 100, 101 (2015), filed as Ex. 37 (ECF No. 40-24)

(“Lyons”). In Dr. Elrick’s view, the infection at issue need not be serious in order to trigger an

autoimmune condition. Tr. at 157.

As the medical record in this case demonstrates, C.L.’s pediatrician noted that C.L. was

congested on October 26, 2020, one day before being hospitalized. Tr. at 85 (discussing Ex. 5 at

11). Other providers at Children’s Healthcare of Atlanta also noted moderate congestion and low-

grade fever that same day, and added rhinorrhea to C.L.’s symptoms on October 28, 2020. Id. at

86–90 (citing Ex. 6 at 635, 864, 866, 871). C.L. also had a Id. at 88–89 (citing Ex. 6 at 864). Then,

when C.L. was hospitalized, treating providers ordered an RVP, which was positive for adenovirus

and rhinovirus/enterovirus. Tr. at 151. While Dr. Bonthius contested the significance of these

results due to their sensitivity (and concomitant ability to pick up inactive viruses), 9 Dr. Elrick

deemed them significant—as had C.L.’s treating providers, who noted that her neurological-like

presentation may have been attributable to her URIs. Id. at 156. Thus, Dr. Elrick felt that C.L.’s

positive RVP test result supported the conclusion that her TM had a post- or para-infectious

etiology. See id. at 157–58, 170, 190.

Other testing results obtained during C.L.’s evaluation did not, in Dr. Elrick’s view, rule

out a post- or para-infectious cause for C.L.’s TM. Her CSF inflammatory marker results, for

example, established the presence of inflammation but would not be indicative of viruses or

infections that could enter the nervous system. Tr. at 153. Rather, infections that are potential TM

triggers are usually systemic infections that generally do not enter the CNS. Id. Similarly, PCR

tests would have been used to rule out meningitis, encephalitis, or an active infection, but evidence

9

Dr. Elrick acknowledged that RVP tests can pick up DNA and RNA left over from inactive infections as they tail

off, but he felt it unlikely that they would pick up the remnants of viruses that were a month old. Tr. at 152–53. Some

tail-off periods have been studied, according to Dr. Elrick, and the period for a positive rhinovirus/enterovirus test

result reflective of a resolved or preexisting infection is rather quick, at seven to ten days. Id.

13

of the presence of a virus in blood serum would not show up on a CSF test either. See id. at 153–

54.

Finally, Dr. Elrick discussed the timeframe in which C.L.’s initial TM symptoms

manifested, deeming it consistent with a viral cause. Tr. at 159–60. TM, and other autoimmune

diseases, have a lag time between the trigger and onset of symptoms, of a few days up to four

weeks. Id. at 159. That period was consistent with both of Petitioner’s viral infections, since the

first was estimated to have begun the month before Petitioner’s hospitalization, and the second

was present leading up to and during the time of hospitalization. Id. at 160. See also Ex. 5 at 11,

17; Ex. 6-2 at 894–95. Thus, either could have been the spark for C.L.’s TM.

On cross examination, Dr. Elrick acknowledged that the CDC had indicated that exposure

to mixed immune stimuli can produce health consequences that can add to or work in tandem with

other biologic or environmental factors, creating new health risks. Tr. at 189; Goldman & Miller

at 1018. This allowed an inference that the vaccines C.L. received, and viral infections she was

then experiencing, could have worked together to trigger C.L.’s TM. Dr. Elrick nevertheless

maintained that the trigger for C.L.’s TM was just as likely to be unknown. See id. at 190.

III. Procedural History

This case was initiated in May 2021, and (after the process for evaluating the sufficiency

of document filings in the case was completed) subsequently assigned to my own docket in June

2022. See Docket Entry, dated June 7, 2022 (ECF No. 27). Respondent filed his Rule 4(c) Report

contesting Petitioner’s right to compensation on October 27, 2022. See Report, dated Oct. 27, 2022

(ECF No. 30). The parties subsequently filed expert reports, completing the process in the fall of

2024. The parties submitted pre-hearing submissions, and trial of the matter occurred as scheduled

in January 2025. Petitioners’ Prehearing Brief, dated Oct. 4, 2024 (ECF No. 62); Respondent’s

Prehearing Brief, dated Nov. 4, 2024 (ECF No. 67); Petitioners’ Prehearing Reply Brief, dated

Dec. 5, 2024 (ECF No. 76). With the filing of post-hearing briefs in late March, the matter became

ripe for resolution. Petitioners’ Post Hearing Brief, dated Mar. 21, 2025 (ECF No. 87) (“Br.”);

Respondent’s Post Hearing Brief, dated Mar. 21, 2025 (ECF No. 88).

IV. Applicable Legal Standards

A. Petitioner’s Overall Burden in Vaccine Program Cases

To receive compensation in the Vaccine Program, a petitioner must prove either: (1) that

he suffered a “Table Injury”—i.e., an injury falling within the Vaccine Injury Table—

corresponding to one of the vaccinations in question within a statutorily prescribed period of time

or, in the alternative, (2) that his illnesses were actually caused by a vaccine (a “Non-Table

Injury”). See Sections 13(a)(1)(A), 11(c)(1), and 14(a), as amended by 42 C.F.R. § 100.3; §

14

11(c)(1)(C)(ii)(I); see also Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315, 1321 (Fed.

Cir. 2010); Capizzano v. Sec’y of Health & Hum. Servs., 440 F.3d 1317, 1320 (Fed. Cir. 2006). 10

There is no Table claim for TM after any of the vaccines at issue.

For both Table and Non-Table claims, Vaccine Program petitioners bear a “preponderance

of the evidence” burden of proof. Section 13(1)(a). That is, a petitioner must offer evidence that

leads the “trier of fact to believe that the existence of a fact is more probable than its nonexistence

before [he] may find in favor of the party who has the burden to persuade the judge of the fact’s

existence.” Moberly, 592 F.3d at 1322 n.2; see also Snowbank Enter. V. United States, 6 Cl. Ct.

476, 486 (1984) (mere conjecture or speculation is insufficient under a preponderance standard).

Proof of medical certainty is not required. Bunting v. Sec’y of Health & Hum. Servs., 931 F.2d

867, 873 (Fed. Cir. 1991). In particular, a petitioner must demonstrate 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)); Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1355 (Fed.

Cir. 2006). A petitioner may not receive a Vaccine Program award based solely on his assertions;

rather, the petition must be supported by either medical records or by the opinion of a competent

physician. Section 13(a)(1).

In attempting to establish entitlement to a Vaccine Program award of compensation for a

Non-Table claim, a petitioner must satisfy all three of the elements established by the Federal

Circuit in Althen v. Sec’y of Health and Hum. Servs., 418 F.3d 1274, 1278 (Fed. Cir. 2005): “(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

proximate temporal relationship between vaccination and injury.”

Each Althen prong requires a different showing. Under Althen prong one, petitioners must

provide a “reputable medical theory,” demonstrating that the vaccine received can cause the type

of injury alleged. Pafford, 451 F.3d at 1355–56 (citations omitted). To satisfy this prong, a

petitioner’s theory must be based on a “sound and reliable medical or scientific explanation.”

Knudsen v. Sec’y of Health & Hum. Servs., 35 F.3d 543, 548 (Fed. Cir. 1994). Such a theory must

only be “legally probable, not medically or scientifically certain.” Id. at 549.

Petitioners may satisfy the first Althen prong without resort to medical literature,

epidemiological studies, demonstration of a specific mechanism, or a generally accepted medical

theory. Andreu v. Sec’y of Health & Hum. Servs., 569 F.3d 1367, 1378–79 (Fed. Cir. 2009) (citing

10

Decisions of special masters (some of which I reference in this ruling) constitute persuasive but not binding

authority. Hanlon v. Sec’y of Health & Hum. Servs., 40 Fed. Cl. 625, 630 (1998). By contrast, Federal Circuit rulings

concerning legal issues are binding on special masters. Guillory v. Sec’y of Health & Hum. Servs., 59 Fed. Cl. 121,

124 (2003), aff’d 104 F. App’x. 712 (Fed. Cir. 2004); see also Spooner v. Sec’y of Health & Hum. Servs., No. 13-

159V, 2014 WL 504728, at *7 n.12 (Fed. Cl. Spec. Mstr. Jan. 16, 2014).

15

Capizzano, 440 F.3d at 1325–26). Special masters, despite their expertise, are not empowered by

statute to conclusively resolve what are essentially thorny scientific and medical questions, and

thus scientific evidence offered to establish Althen prong one is viewed “not through the lens of

the laboratorian, but instead from the vantage point of the Vaccine Act’s preponderant evidence

standard.” Id. at 1380. Distinguishing between “preponderant evidence” and “medical certainty”

is important because special masters must take care not to impose an evidentiary burden that is too

high. Bunting v. Sec'y of Health & Human Servs., 931 F.2d 867, 873 (Fed.Cir.1991) (“The standard

of proof required by the [Vaccine] Act is simple preponderance of evidence; not scientific

certainty.... [I]t is not plaintiff's burden to disprove every possible ground of causation suggested

by defendant nor must the findings of the court meet the standards of the laboratorian.”) (citations

and internal quotation marks omitted).

In discussing the evidentiary standard applicable to the first Althen prong, the Federal

Circuit has consistently rejected the contention that it can be satisfied merely by establishing the

proposed causal theory’s scientific or medical plausibility. See Cerrone v. Sec'y of Health & Hum.

Servs., 146 F.4th 1113, 1122 (Fed. Cir. 2025); Kalajdzic v. Sec’y of Health & Hum. Servs., No.

2023-1321, 2024 WL 3064398, at *2 (Fed. Cir. June 20, 2024) (arguments “for a less than

preponderance standard” deemed “plainly inconsistent with our precedent” (citing Moberly, 592

F.3d at 1322)); Boatmon v. Sec’y of Health & Hum. Servs., 941 F.3d 1351, 1359 (Fed. Cir. 2019);

see also Demore v. Sec'y of Health & Hum. Servs., No. 20-1265V, 2024 WL 4542934 (Fed. Cl.

Spec. Mstr. Sept. 26, 2024), aff'd, No. 20-1265V, 2025 WL 868902, at *4 (Fed. Cl. Mar. 20, 2025)

(rejecting the argument that a petitioner’s burden is to prove that a causation theory is plausible

and instead requiring petitioner to prove the theory by a preponderance of the evidence) (emphasis

added). And petitioners always have the ultimate burden of establishing their overall Vaccine Act

claim with preponderant evidence. W.C. v. Sec’y of Health & Hum. Servs., 704 F.3d 1352, 1356

(Fed. Cir. 2013) (citations omitted); Tarsell v. United States, 133 Fed. Cl. 782, 793 (2017) (noting

that Moberly “addresses the petitioner’s overall burden of proving causation-in-fact under the

Vaccine Act” by a preponderance standard).

The second Althen prong requires proof of a logical sequence of cause and effect, usually

supported by facts derived from a petitioner’s medical records. Althen, 418 F.3d at 1278; Andreu,

569 F.3d at 1375–77; Capizzano, 440 F.3d at 1326; Grant v. Sec’y of Health & Hum. Servs., 956

F.2d 1144, 1148 (Fed. Cir. 1992). In establishing that a vaccine “did cause” injury, the opinions

and views of the injured party’s treating physicians are entitled to some weight. Andreu, 569 F.3d

at 1367; Capizzano, 440 F.3d at 1326 (“medical 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 particularly

trustworthy evidence, since they are created contemporaneously with the treatment of the patient.

Cucuras v. Sec’y of Health & Hum. Servs., 993 F.2d 1525, 1528 (Fed. Cir. 1993).

16

Medical records and statements of a treating physician, however, do not per se bind the

special master to adopt the conclusions of such an individual, even if they must be considered and

carefully evaluated. Section 13(b)(1) (providing that “[a]ny such diagnosis, conclusion, judgment,

test result, report, or summary shall not be binding on the special master or court”); Snyder v. Sec’y

of Health & Hum. Servs., 88 Fed. Cl. 706, 746 n.67 (2009) (“there is nothing . . . that mandates

that the testimony of a treating physician is sacrosanct—that it must be accepted in its entirety and

cannot be rebutted”). As with expert testimony offered to establish a theory of causation, the

opinions or diagnoses of treating physicians are only as trustworthy as the reasonableness of their

suppositions or bases. The views of treating physicians should be weighed against other, contrary

evidence also present in the record—including conflicting opinions among such individuals.

Hibbard v. Sec’y of Health & Hum. Servs., 100 Fed. Cl. 742, 749 (2011) (not arbitrary or capricious

for special master to weigh competing treating physicians’ conclusions against each other), aff’d,

698 F.3d 1355 (Fed. Cir. 2012); Veryzer v. Sec’y of Dept. of Health & Hum. Servs., No. 06-522V,

2011 WL 1935813, at *17 (Fed. Cl. Spec. Mstr. Apr. 29, 2011), mot. for review den’d, 100 Fed.

Cl. 344, 356 (2011), aff’d without opinion, 475 F. Appx. 765 (Fed. Cir. 2012).

The third Althen prong requires establishing a “proximate temporal relationship” between

the vaccination and the injury alleged. Althen, 418 F.3d at 1281. That term has been equated to the

phrase “medically-acceptable temporal relationship.” Id. A petitioner must offer “preponderant

proof that the onset of symptoms occurred within a timeframe which, given the medical

understanding of the disorder’s etiology, it is medically acceptable to infer causation.” De Bazan

v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1352 (Fed. Cir. 2008). The explanation for what

is medically acceptable timeframe must align with the theory of how the relevant vaccine can cause

an injury (Althen prong one’s requirement). Id. at 1352; Shapiro v. Sec’y of Health & Hum. Servs.,

101 Fed. Cl. 532, 542 (2011), recons. Den’d after remand, 105 Fed. Cl. 353 (2012), aff’d mem.,

503 F. Appx. 952 (Fed. Cir. 2013); Koehn v. Sec’y of Health & Hum. Servs., No. 11-355V, 2013

WL 3214877 (Fed. Cl. Spec. Mstr. May 30, 2013), mot. for rev. den’d (Fed. Cl. Dec. 3, 2013),

aff’d, 773 F.3d 1239 (Fed. Cir. 2014).

B. Legal Standards Governing Factual Determinations

The process for making determinations in Vaccine Program cases regarding factual issues

begins with consideration of the medical records. Section 11I(2). The special master is required to

consider “all [ ] relevant medical and scientific evidence contained in the record,” including “any

diagnosis, conclusion, medical judgment, or autopsy or coroner’s report which is contained in the

record regarding the nature, causation, and aggravation of the petitioner’s illness, disability, injury,

condition, or death,” as well as the “results of any diagnostic or evaluative test which are contained

in the record and the summaries and conclusions.” Section 13(b)(1)(A). The special master is then

required to weigh the evidence presented, including contemporaneous medical records and

17

testimony. See Burns v. Sec’y of Health & Hum. Servs., 3 F.3d 415, 417 (Fed. Cir. 1993)

(determining that it is within the special master’s discretion to determine whether to afford greater

weight to contemporaneous medical records than to other evidence, such as oral testimony

surrounding the events in question that was given at a later date, provided that such determination

is evidenced by a rational determination).

As noted by the Federal Circuit, “[m]edical records, in general, warrant consideration as

trustworthy evidence.” Cucuras, 993 F.2d at 1528; Doe/70 v. Sec’y of Health & Hum. Servs., 95

Fed. Cl. 598, 608 (2010) (“[g]iven the inconsistencies between petitioner’s testimony and his

contemporaneous medical records, the special master’s decision to rely on petitioner’s medical

records was rational and consistent with applicable law”), aff’d, Rickett v. Sec’y of Health & Hum.

Servs., 468 F. App’x 952 (Fed. Cir. 2011) (non-precedential opinion). A series of linked

propositions explains why such records deserve some weight: (i) sick people visit medical

professionals; (ii) sick people attempt to honestly report their health problems to those

professionals; and (iii) medical professionals record what they are told or observe when examining

their patients in as accurate a manner as possible, so that they are aware of enough relevant facts

to make appropriate treatment decisions. Sanchez v. Sec’y of Health & Hum. Servs., No. 11–685V,

2013 WL 1880825, at *2 (Fed. Cl. Spec. Mstr. Apr. 10, 2013); Cucuras, 993 F.2d at 1525 (“[i]t

strains reason to conclude that petitioners would fail to accurately report the onset of their

daughter’s symptoms”).

Accordingly, if the medical records are clear, consistent, and complete, then they should

be afforded substantial weight. Lowrie v. Sec’y of Health & Hum. Servs., No. 03–1585V, 2005

WL 6117475, at *20 (Fed. Cl. Spec. Mstr. Dec. 12, 2005). Indeed, contemporaneous medical

records are often found to be deserving of greater evidentiary weight than oral testimony—

especially where such testimony conflicts with the record evidence. Cucuras, 993 F.2d at 1528;

see also 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), cert. den’d, Murphy v. Sullivan, 506 U.S. 974 (1992) (citing United

States v. United States Gypsum Co., 333 U.S. 364, 396 (1947) (“[i]t has generally been held that

oral testimony which is in conflict with contemporaneous documents is entitled to little evidentiary

weight.”)).

However, the Federal Circuit has also noted that there is no formal “presumption” that

records are accurate or superior on their face to other forms of evidence. Kirby v. Sec’y of Health

& Hum. Servs., 997 F.3d 1378, 1383 (Fed. Cir. 2021). There are certainly situations in which

compelling oral or written testimony (provided in the form of an affidavit or declaration) 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) (“like 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, 2005 WL

18

6117475, at *19 (“[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, 569 F.3d at 1379; Bradley v. Sec’y of

Health & Hum. Servs., 991 F.2d 1570, 1575 (Fed. Cir. 1993).

When witness testimony is offered to overcome the presumption of accuracy afforded to

contemporaneous medical records, such testimony must be “consistent, clear, cogent, and

compelling.” Sanchez, 2013 WL 1880825, at *3 (citing Blutstein v. Sec’y of Health & Hum. Servs.,

No. 90–2808V, 1998 WL 408611, at *5 (Fed. Cl. Spec. Mstr. June 30, 1998)). In determining the

accuracy and completeness of medical records, the Court of Federal Claims has listed four possible

explanations for inconsistencies between contemporaneously created medical records and later

testimony: (1) a person’s failure to recount to the medical professional everything that happened

during the relevant time period; (2) the medical professional’s failure to document everything

reported to her or him; (3) a person’s faulty recollection of the events when presenting testimony;

or (4) a person’s purposeful recounting of symptoms that did not exist. La Londe v. Sec’y of Health

& Hum. Servs., 110 Fed. Cl. 184, 203–04 (2013), aff’d, 746 F.3d 1334 (Fed. Cir. 2014). In making

a determination regarding whether to afford greater weight to contemporaneous medical records

or other evidence, such as testimony at hearing, there must be evidence that this decision was the

result of a rational determination. Burns, 3 F.3d at 417.

C. Analysis of Expert Testimony

Establishing a sound and reliable medical theory often requires a petitioner to present

expert testimony in support of his claim. Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357,

1361 (Fed. Cir. 2000). Vaccine Program expert testimony is usually evaluated according to the

factors for analyzing scientific reliability set forth in Daubert v. Merrell Dow Pharm., Inc., 509

U.S. 579, 594–96 (1993). See Cedillo v. Sec’y of Health & Hum. Servs., 617 F.3d 1328, 1339 (Fed.

Cir. 2010) (citing Terran v. Sec’y of Health & Hum. Servs., 195 F.3d 1302, 1316 (Fed. Cir. 1999).

Under Daubert, the factors for analyzing the reliability of testimony are:

(1) whether a theory or technique can be (and has been) tested; (2) whether the

theory or technique has been subjected to peer review and publication; (3) whether

there is a known or potential rate of error and whether there are standards for

controlling the error; and (4) whether the theory or technique enjoys general

acceptance within a relevant scientific community.

Terran, 195 F.3d at 1316 n.2 (citing Daubert, 509 U.S. at 592–95).

In the Vaccine Program the Daubert factors play a slightly different role than they do when

19

applied in other federal judicial settings, like the district courts. Typically, Daubert factors are

employed by judges (in the performance of their evidentiary gatekeeper roles) to exclude evidence

that is unreliable or could confuse a jury. By contrast, in Vaccine Program cases these factors are

used in the weighing of the reliability of scientific evidence proffered. Davis v. Sec’y of Health &

Hum. Servs., 94 Fed. Cl. 53, 66–67 (2010) (“uniquely in this Circuit, the Daubert factors have

been employed also as an acceptable evidentiary-gauging tool with respect to persuasiveness of

expert testimony already admitted”). The flexible use of the Daubert factors to evaluate the

persuasiveness and reliability of expert testimony has routinely been upheld. See, e.g., Snyder, 88

Fed. Cl. at 742–45. In this matter (as in numerous other Vaccine Program cases), Daubert has not

been employed at the threshold, to determine what evidence should be admitted, but instead to

determine whether expert testimony offered is reliable and/or persuasive.

Respondent frequently offers one or more experts in order to rebut a petitioner’s case.

Where both sides offer expert testimony, a special master’s decision may be “based on the

credibility of the experts and the relative persuasiveness of their competing theories.”

Broekelschen v. Sec’y of Health & Hum. Servs., 618 F.3d 1339, 1347 (Fed. Cir. 2010) (citing

Lampe, 219 F.3d at 1362). However, nothing requires the acceptance of an expert’s conclusion

“connected to existing data only by the ipse dixit of the expert,” especially if “there is simply too

great an analytical gap between the data and the opinion proffered.” Snyder, 88 Fed. Cl. at 743

(quoting Gen. Elec. Co. v. Joiner, 522 U.S. 146 (1997)); see also Isaac v. Sec’y of Health & Hum.

Servs., No. 08–601V, 2012 WL 3609993, at *17 (Fed. Cl. Spec. Mstr. July 30, 2012), mot. for

review den’d, 108 Fed. Cl. 743 (2013), aff’d, 540 F. App’x. 999 (Fed. Cir. 2013) (citing Cedillo,

617 F.3d at 1339). Weighing the relative persuasiveness of competing expert testimony, based on

a particular expert's credibility, is part of the overall reliability analysis to which special masters

must subject expert testimony in Vaccine Program cases. Moberly, 592 F.3d at 1325–26

(“[a]ssessments as to the reliability of expert testimony often turn on credibility determinations”);

see also Porter v. Sec’y of Health & Hum. Servs., 663 F.3d 1242, 1250 (Fed. Cir. 2011) (“this

court has unambiguously explained that special masters are expected to consider the credibility of

expert witnesses in evaluating petitions for compensation under the Vaccine Act”).

D. Consideration of Medical Literature

Both parties filed medical and scientific literature in this case, but not all such items factor

into the outcome of this decision. While I have reviewed all the medical literature submitted, I

discuss only those articles that are most relevant to my determination and/or are central to

Petitioner’s case—just as I have not exhaustively discussed every individual medical record filed.

Moriarty v. Sec’y of Health & Hum. Servs., No. 2015–5072, 2016 WL 1358616, at *5 (Fed. Cir.

Apr. 6, 2016) (“[w]e generally presume that a special master considered the relevant record

evidence even though he does not explicitly reference such evidence in his decision”) (citation

omitted); see also Paterek v. Sec’y of Health & Hum. Servs., 527 F. App’x 875, 884 (Fed. Cir.

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2013) (“[f]inding certain information not relevant does not lead to—and likely undermines—the

conclusion that it was not considered”).

ANALYSIS

I. Treatment of Transverse Myelitis in Vaccine Program

TM is a rare, neuro-immune disorder “characterized by focal inflammation within the

spinal cord.” Krishnan at 1483; Greenberg at 2. Symptoms and presentation can vary, but generally

it appears with “rapid onset of weakness, sensory alterations, and bowel or bladder dysfunction.”

Greenberg at 2. TM’s etiology is varied, and while it has been associated with various infectious

or systemic autoimmune diseases, it often is deemed idiopathic in origin. Greenberg at 2; Borchers

at 231. Importantly, and as Program decisions recognize, TM typically presents acutely—

especially when measured from the time of an allegedly-causal trigger. See, e.g., Handjis v. Sec'y

of Health & Hum. Servs., No. 18-1044V, 2022 WL 17852426, at *16 (Fed. Cl. Dec. 5, 2022) (“[i]f

one were to accept that petitioner received a high dose flu vaccine on December 10, 2015, and

presented on December 14, 2015 with symptoms that were ultimately diagnosed as TM and

supported by objective testing, then petitioner would have satisfied [Althen] Prong III”); Raymo v.

Sec'y of Health & Hum. Servs., No. 11-0654V, 2014 WL 1092274, at *10, *19 (Fed. Cl. Spec.

Mstr. Feb. 24, 2014) (onset of TM occurred between three to four days after vaccination and was

consistent for an immune mediated disorder).

The treatment of TM in the vaccine program is as varied as its etiologies. Petitioners have

succeeded in claims that different covered vaccines can cause TM. See e.g., Schmidt v. Sec'y of

Health & Human Servs., No. 07-20V, 2009 WL 5196169 (Fed. Cl. Spec. Mstr. Dec. 17, 2009)

(granted entitlement on a claim that an influenza vaccine caused Petitioner’s TM via molecular

mimicry). However, as with any case, the specific factors of an individual vaccinee’s medical

history can impact success, even when the causal theory finds favor. See, e.g., Palattao v. Sec'y of

Health & Hum. Servs., No. 13-591V, 2019 WL 989380 (Fed. Cl. Spec. Mstr. Feb. 4, 2019)

(denying entitlement in TM case where petitioners failed to establish that timing of onset of

symptoms was medically appropriate under their proposed causation theory).

II. Petitioner has failed to Satisfy Althen Prong Two

Petitioners have failed to carry their burden of preponderantly establishing that C.L.’s four-

month vaccines “did cause” (alone or in substantial contribution to) her TM. See Althen, 418 F.3d

at 1281. This is a sufficient basis for denying entitlement, since all three Althen prongs must be

established. Dobrydnev v. Sec’y of Health & Hum. Servs., 566 Fed. Appx. 976, 980 (Fed. Cir.

2014). (And for this reason, I include no discussion of Petitioner’s success in meeting the first or

third Althen prongs).

21

To begin, the record lacks evidence that C.L. experienced any kind of reaction from the

October 7, 2020 vaccines. Tr. at 105. At most (and based on comments made to treaters in later

October 2020 by the Petitioners), C.L. may have been previously exposed to others suffering from

an infection, or had experienced infectious symptoms of her own, before vaccination or in a

timeframe consistent with the period leading up to her October 26th pediatric visit. Tr. at 41; Ex. 6

at 632, 865. C.L. clearly did not experience a fever or any other reaction in the days after the

vaccinations that would warrant a doctor or hospital visit. Indeed, her first reported symptom

occurred on October 26, 2020—the day she was first brought to the pediatrician.

The next (and even more compelling) evidentiary factor preventing a finding of causation

is the strong evidence that C.L. was beginning to experience URI symptoms around the time of

her onset. C.L. was noted to have some recurrent symptoms of congestion and low-grade fever

throughout the time of her neurologic symptoms progression. Ex. 5 at 11; Ex. 6 at 635; Ex. 6 at

864. But she only started experiencing such symptoms (like weakness in the limbs) on October 26,

2025. While these neurologic symptoms literally occurred “post-vaccination,” they only

manifested in the wake of her confirmed URI symptoms—which were themselves far closer-in-

time to likely TM onset. By contrast, the record reveals no medical issues in the 19 days between

vaccination and C.L.’s first subsequent medical encounter.

All of the foregoing supports the conclusion that some kind of infectious process was going

on around the time Petitioner was taken to the pediatrician 19 days post-vaccination. And literature

filed in this case affirms that an infection can be causal of TM. See e.g., Lyons at 101–02; Borchers

at Table 5, 241; Karussis at 220; Agmon-Levin at 1199; Greenberg at 2. Petitioners’ expert did not

adequately diminish the significance of this evidence. Rather, Dr. Bonthius attempted to deny the

existence of some symptoms C.L. experienced in the days leading up to her until confronted with

the medical records documenting them on cross examination. See Tr. at 85–90. Of course,

claimants need not affirmatively exclude all alternative factors that could explain an alleged

vaccine injury. Efron v. Sec'y of Health & Hum. Servs., No. 20-1405V, 2025 WL 408219, at *22

(Fed. Cl. Spec. Mstr. Jan. 2, 2025) (citing M.R. v. Sec'y of Health & Hum. Servs., No. 16-1024V,

2023 WL 4936727, at *30 (Fed. Cl. Spec. Mstr. June 30, 2023)). But they have some obligation

to grapple with the record when it establishes the existence of such countervailing factors—and

Petitioner failed here to do so.

Besides such clinical symptoms of an infection, the record also contains proof that C.L.

tested positive for a number of specific infections—adenovirus and rhinovirus/enterovirus. She

tested positive for all of those infections on October 27, 2020, only a day after first being brought

to see a pediatrician. Ex. 6 at 640, 925. Accordingly, and in addition to clinical evidence that C.L.

was ill for reasons other than her later-diagnosed TM at the time, there are demonstrated instances

in her medical history where she tested positive for specific infections that could be causal of TM.

22

Respondent made reasonable points as to how these viruses are linked to the development

of TM, and the fact that the timing of the testing result did not preclude the possibility that such

an infection existed at the time of the C.L.’s onset. Dr. Bonthius, by contrast, tried to undermine

the significance of these results by challenging whether the tests actually showed active viral

infections. But Dr. Elrick’s testimony as to the tail-off period for a rhinovirus/enterovirus infection

was persuasive. Dr. Elrick testified that the tail off period for such an infection (for purposes of

testing results) is approximately seven to ten days, and would likely not trigger a positive result a

month after infection. Id. at 152–53. This suggests it was more likely in this case that C.L.’s

rhinovirus/enterovirus infections could have been relatively active at the time of testing—

consistent with the URI symptoms she displayed. And none of C.L.’s treating providers opined

that the test results were a false positive, or were indicative of inactive viruses.

In fact, on the issue of treater views, Petitioners cannot point to instances in the record

where C.L.’s treaters proposed that her four-month vaccines were the cause of her TM. Yet some

of those same treaters did speculate that an infection could have been the cause of her neurologic

affliction (albeit in the context of an AFM diagnosis). See Ex. 6 at 1132. Certainly, treater opinions

are not per se controlling of the outcome. Al-Uffi v. Sec'y of Health & Hum. Servs., No. 13-956V,

2017 WL 1713113, at *13 (Fed. Cl. Spec. Mstr. Feb. 22, 2017). But no provider has opined the

cause of C.L.’s TM after her diagnosis, and none embraced vaccination as explanatory. Thus, this

is not a case where treater views help proving the “did cause” prong (and if anything, the absence

of such favorable views hurts Petitioner’s prong two showing).

Thus, the primary evidence in favor of Petitioners’ claim on the “did cause” prong is the

naked, approximately three-week temporal association between C.L.’s four-month vaccines and

onset of her TM. But post hoc ergo propter hoc reasoning does not satisfy Althen prong two.

Fricano v. United States, 22 Cl. Ct. 796, 800 (1991) (citing Loesch v. United States, 227 Ct. Cl.

34, 45, 645 F.2d 905, 914 (post hoc ergo propter hoc approach to causation is unpersuasive), cert.

denied, 454 U.S. 1099, 102 S. Ct. 672, 70 L.Ed.2d 640 (1981); Doe/34 v. Sec'y of Health & Hum.

Servs., 2009 WL 1955140, at *10 (Fed. Cl. Mar. 4, 2009), aff'd sub nom. Jane Doe*34 v. Sec'y of

Health & Hum. Servs., 87 Fed. Cl. 758 (2009) (citing Grant v. Sec'y of Health & Hum. Servs, 956

F.2d 1144, 1148 (Fed.Cir.1992) (“the inoculation is not the cause of every event that occurs

[after].... Without more, this proximate temporal relationship will not support a finding of

causation”)).

The very case reports relied upon by Petitioners note that a temporal relationship is not

sufficient to determine causation. See Riel Romero at 690 (“[a]lthough there is a temporal

relationship between the development of transverse myelitis and DTaP vaccination in our patient,

it is difficult to establish a causal relationship between the two. The occurrence could have been

simply coincidental”); Karussis at 221 (“[t]here is no absolute way to definitely link the onset or

exacerbation of demyelination with the vaccine, but the close temporal association with the time

23

of vaccination strongly argues in favor or such pathogenetic correlation”); Kaplin at 4

(“[t]herefore, such case reports must be viewed with caution, as it is entirely possible that 2 events

occurred in close proximity by chance alone or for reasons that are only incidentally related to the

vaccination procedure”). 11

Admittedly, an argument could be made in some cases that the combination of an

intercurrent infectious process and vaccination might synergistically work together to cause an

injury—even where it is not clear which factor predominated. See, e.g., Xia v. Sec’y of Health &

Hum. Servs., No. 20-1924V, slip op. at 25–26 (Fed. Cl. Spec. Mstr. Aug. 29, 2025) (record

supported the conclusion that the receipt of a vaccine at the same time a child was severely ill

allowed for the likelihood that both interacted synergistically, leading to Febrile Infection-Related

Epilepsy Syndrome). This is sometimes in the Program thought of as a “Shyface analysis,” where

two competing factors are present, either of which could cause an adverse event, but where one

cannot be ascertained to have been more likely causal than the other. See Shyface, 165 F.3d at

1352. Here, Petitioners have argued that they can still prevail even if other infectious factors (the

adenovirus and rhinovirus/enterovirus) were partially causal, because claimants only need show

that a vaccine was a “substantial factor” and “but for” cause of their injury. Br. at 31–37 (discussing

Shyface, 165 F.3d at 1352).

On the basis of this record, however, I do not find that Shyface provides a basis for a

favorable prong two determination. First, this is not a case in which Respondent’s expert conceded

that any of the vaccines C.L. received could explain her TM, such that vaccines present an

alternative causal explanation, competing with an infectious etiology. Thus, the vaccines C.L.

received cannot be deemed, at least on face value, to pose the same risk of TM as infections.

Second, even if I had found in favor of Petitioner on this issue, the record still does not support

the conclusion that the vaccines likely played any role at all in her injury. Thus, she displayed no

reaction at all to the vaccines, with nearly three weeks passing before her pediatric visit that

immediately preceded her TM diagnosis occurred; she had experienced not only some admitted

infectious exposure around the relevant time period, but displayed a number of symptoms of an

infection (far closer in time to her neurologic onset); and then she tested positive for several

infections, all of which were as likely to cause TM as vaccines—if not more so. In this context, a

viral infection as the explanation for C.L.’s illness is better supported by the record.

Petitioners’ arguments on this front likely arise in part from the view that C.L.’s prior

vaccinations were at work causing the manufacture of pathogenic, cross-reactive antibodies

11

I also note that many of the filed case reports better support a shorter onset. See Whittle & Robinson at 1450 (onset

of symptoms occurring six to seven days after vaccination); Karussis at Table 2 (showing multiple instances of myelitis

onset occurring a few days after vaccination). While such matters somewhat relate to Petitioner’s success on the third

Althen prong, they also go to the question of whether it has been shown that vaccines administered three weeks before

onset could be implicated in a disease process where there is no other record evidence to suggest the vaccination

event was harmful.

24

capable of instigating TM, and that an ongoing (but subclinical) immune process in turn interacted

with C.L.’s infection exposure. Again, the temporal interval between vaccination and TM onset at

evidence in this matter undermines such a theory. 12 But even when a vaccine is received at the

very time an individual is also experiencing an active infection, it cannot be presumed that the

vaccine likely played some contributory role in any resulting disease or injury. See, e.g., K.A. v.

Sec'y of Health & Hum. Servs., No. 16-989V, 2022 WL 20213037 (Fed. Cl. Spec. Mstr. Apr. 18,

2022) (Tdap vaccine not causal of GBS; petitioner had been experiencing active upper respiratory

infection more likely causal), mot. for review den’d, 164 Fed. Cl. 98 (2022), aff'd, 2024 WL

2012526 (Fed. Cir. 2024). The fact the vaccine was “known” to have been administered also does

not mean it is more likely causal, even if an alternative explanation cannot be identified with the

same precision. K.A., WL 20213037, at *31 (“[t]he vaccine does not deserve greater weight simply

because it is “known” whereas the precise nature of the infection is not”); see also Randolph v.

Sec'y of Health & Hum. Servs., No. 15-146V, 2021 WL 5816271, at *21 (Fed. Cl. Spec. Mstr.

Nov. 12, 2021) (“[c]ausation claims do not succeed merely because Respondent cannot prove with

certainty what was causal”).

I cannot on this record identify what her most likely specific infectious trigger for C.L.’s

TM was. But that same record does not allow a finding that any of the vaccines C.L. received were

also a substantial factor in causing her TM.

CONCLUSION

Because Petitioners have not carried their burden of proof, they are not entitled to damages. In

the absence of a motion for review filed pursuant to RCFC Appendix B, the Clerk of the Court

SHALL ENTER JUDGMENT in accordance with the terms of this Decision. 13

IT IS SO ORDERED.

/s/ Brian H. Corcoran

Brian H. Corcoran

Chief Special Master

12

Thus, this is not a case where the timeframe/overlap of vaccination and infection was tighter, making it far more

difficult to tease out causality. Cf. Xia, No. 20-1924V, slip op. at 28 (child received flu vaccine on the same day she

was taken to see treaters for particularly virulent infection, with clear record evidence of concerning infectious

symptoms at that time).

13

Pursuant to Vaccine Rule 11(a), the parties may expedite entry of judgment if (jointly or separately) they file notices

renouncing their right to seek review.

25