Brown v. Secretary of Health and Human Services

In the United States Court of Federal Claims

OFFICE OF SPECIAL MASTERS

Filed: December 16, 2025

* * * * * * * * * * *

* *

EUGENE ANTHONY BROWN, *

*

Petitioner, * No. 20-426V

*

v. * Special Master Gowen

*

SECRETARY OF HEALTH * Idiopathic Thrombocytopenia;

AND HUMAN SERVICES, * Twinrix; Influenza; Tdap; IPV.

*

Respondent. *

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

Nathaniel C. Enos, Conway Homer, P.C., Boston, MA, for petitioner.

Sarah B. Rifkin, U.S. Dept. of Justice, Washington, DC, for respondent.

DECISION1

On April 14, 2020, Eugene Anthony Brown (“petitioner”) filed a petition for

compensation in the National Vaccine Injury Compensation Program.2 Petition (ECF No. 1).

Petitioner alleges that the Hepatitis A and Hepatitis B (“Twinrix”), influenza (“Flu”), inactivated

polio (“IPV”), meningococcal (“MCV4P”), and tetanus-diphtheria-acellular-pertussis (“Tdap”)

vaccines he received on May 18, 2017, caused him to suffer from chronic idiopathic

thrombocytopenic purpura (“ITP”) and sequalae. Amended Petition at ¶ 5 (ECF No. 19). Based

on a review of the evidence submitted in the record, the undersigned finds that petitioner has

failed to establish that he is entitled to compensation. Therefore, entitlement is DENIED and the

case shall be DISMISSED. 3

1

Because this Ruling contains a reasoned explanation for the action taken in this case, it must be made publicly

accessible and will be posted 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, I agree that the identified material fits within this

definition, I 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 (2012)

(hereinafter “Vaccine Act” or “the Act”). Hereinafter, individual section references will be to 42 U.S.C. § 300aa of

the Act.

3

Pursuant to Section 13(a)(1), in order to reach my decision, I have considered the entire record, including all

of the medical records, expert records, and literature submitted by the parties. This opinion discusses the

elements of the record I found most relevant to the outcome.

I. Procedural History

Petitioner initiated his claim on April 14, 2020, alleging that the MMR and varicella

vaccinations he received on May 17, 2017, caused him to suffer from ITP. Petition at Preamble.

Petitioner filed an Amended Petition on September 28, 2020 changing the causal vaccines to the

Twinrix, Flu, IPV, MCV4P, and Tdap vaccines, which he received on May 18, 2017 based on his

medical records. Amended Petition at ¶ 5. Petitioner filed an expert report from Dr. Edwin N.

Forman on February 14, 2022. Petitioner (“Pet’r”) Exhibit (“Ex.”) 18 (ECF No. 31). Respondent

filed responsive expert reports from Dr. Michele P. Lambert and Dr. Ross M. Kedl on August

15, 2022. Respondent (“Resp’t”) Ex. A (ECF No. 37); Resp’t Ex. C (ECF No. 38-1). The

undersigned subsequently held a Rule 5 status conference, after which Petitioner filed a

supplemental expert report from Dr. Forman. Pet’r Ex. 54 (ECF No. 46). Respondent later filed a

responsive supplemental report from Dr. Lambert. Resp’t Ex. E (ECF No. 56). The parties opted

to resolve the case on the record in lieu of having an entitlement hearing.

Petitioner filed a motion for ruling on the record on August 5, 2024, and respondent filed

his response on September 4, 2024. Pet’r Mot. for Ruling on the Record (“Pet’r Br.”) (ECF No.

62); Resp’t Resp. to Pet’r Mot. for Ruling on the Record (“Resp’t Br.”) (ECF No. 63). Petitioner

filed his reply on September 19, 2024. Pet’r Reply (ECF No. 64).

The matter is now ripe for adjudication.

II. Legal Standard for Adjudication

To receive compensation through the Program, petitioner must prove either (1) that [he]

suffered a “Table Injury”—i.e., an injury listed on the Vaccine Injury Table—corresponding to a

vaccine that she received, or (2) that he suffered an injury that was actually caused by a

vaccination. See §§ 11(c)(1), 13(a)(1)(A); Capizzano v. Sec’y of Health & Hum. Servs., 440 F.3d

1317, 1319-20 (Fed. Cir. 2006). Because petitioner does not allege that he suffered a Table

Injury, he must prove that a vaccine he received caused his injury. To do so, he must establish,

by preponderant evidence: (1) a medical theory causally connecting the vaccine and his injury

(“Althen Prong One”); (2) a logical sequence of cause and effect showing that the vaccine was

the reason for his injury (“Althen Prong Two”); and (3) a showing of a proximate temporal

relationship between the vaccine and his injury (“Althen Prong Three”). § 13(a)(1); Althen, 418

F.3d at 1278.

The causation theory must relate to the injury alleged. The 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). Recently, in

Kottenstette, the Federal Circuit reiterated that proof of causation does not “require identification

and proof of specific biological mechanisms[.]” Kottenstette v. Sec’y of Health & Hum. Servs., --

Fed.Appx.—(Fed. Cir. June 15, 2021) (citing Knudsen v. Sec’y of Health & Hum. Servs., 35 F.3d

543, 549 (Fed. Cir. 1994). Causation “can be found in vaccine cases….without detailed medical

and scientific exposition of the biological mechanisms.” Knudsen, 35 F.3d 543, 548-49 (Fed.

Cir. 1994). It is not necessary for a petitioner to point to conclusive evidence in the medical

2

literature linking a vaccine to the petitioner’s injury, as long as the petitioner can show by a

preponderance of evidence that there is a causal relationship between the vaccine and the injury,

whatever the details of the mechanism may be. Moberly v. Sec’y of Health & Hum. Servs., 592

F.3d 1315, 1325 (Fed. Cir. 2010).

Petitioner cannot establish entitlement to compensation based solely on his 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 undersigned 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).

In Vaccine Act cases, expert testimony may be 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 also Cedillo, 617 F.3d at 1339 (citing Terran v. Sec’y of Health & Hum.

Servs., 195 F.3d 1302, 1316 (Fed. Cir. 1999). In Vaccine Program cases, the Daubert analysis

has been used in the weighing of the scientific evidence actually proffered and heard rather than

as a tool for the pre-trial exclusion of expert testimony. Davis v. Sec'y of Health & Hum. Servs.,

94 Fed. Cl. 53, 66–67 (Fed. Cl. 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”), aff'd, 420 F. App'x 923 (Fed. Cir. 2011). The flexible use of

the Daubert factors to determine the persuasiveness and/or reliability of expert testimony in

Vaccine Program cases has routinely been upheld. See, e.g., Snyder v. Sec'y of Health & Hum.

Servs., 88 Fed. Cl. 706, 742–45 (2009). 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”).

Close calls regarding causation must be resolved in favor of the petitioner. Althen, 418

F.3d at 1280 (holding that Congress created a system in which “close calls regarding causation

are resolved in favor of injured claimants”); Knudsen, 35 F.3d at 551 (“If the evidence (on

alternative cause) is seen in equipoise, then the government has failed in its burden of persuasion

and compensation must be awarded.”).

III. Summary of Evidence Submitted

a. Medical Records

3

i. Petitioner’s Pre-Vaccination Medical History

Petitioner was born on May 28, 1998 and was nineteen years old when he received the

vaccines at issue. Pet’r Ex. 1 at 1; Pet’r Ex. 3 at 25. In the three years prior to vaccination, he did

not seek medical care beyond treatment for sports-related concerns and periodic visits to his local

CVS Minute Clinic and his primary care provider (“PCP”), Jim Hussey, D.O. See generally Pet’r

Ex. 2 at 19-35; Pet’r Ex. 14 at 3-13; Pet’r Ex. 6 at 3. On September 21, 2015, at age seventeen,

petitioner saw Dr. Hussey for a respiratory illness, sinusitis and pneumonia. Pet’r Ex. 2 at 28.

He underwent lab testing as part of his care, and a complete blood count (“CBC”) revealed a low

platelet count of 92 K/uL.5 Ex. 2 at 115. Although petitioner had originally sought care for

respiratory symptoms, Dr. Hussey became concerned about the low platelet count incidentally

discovered through the lab work. See Pet’r Ex. 7 at 50, 61-62. Dr. Hussey called petitioner at

home and advised him to visit the emergency department (“ED”) as soon as possible. Id. at 50.

See also Id. at 61-62 (fax cover sheets sent to the Lake Pointe ED, including handwritten notes

directing that petitioner be seen “in ED STAT!”) (emphasis original). Petitioner went to the ED

that day, and a repeat CBC showed a platelet count of 121 K/uL. Id. at 135. Petitioner was

treated for his respiratory symptoms and discharged. Id. at 57-60.

Three days later, on September 25, 2015, petitioner returned to his PCP for a follow-up

exam. Pet’r Ex. 2 at 24. Petitioner’s headache had “much improved” and his platelet level had

risen to 196 K/ul, a normal level. Id. at 112. There are no records of additional platelet counts

recorded at any time in his life prior to September 2015. There were also no other blood draws

between September 25, 2015 and May 18, 2017, when he received the Hepatitis A and Hepatitis

B (“Twinrix”), influenza (“flu”), inactivated polio (“IPV”), meningococcal (“MCV4P”), and

tetanus-diphtheria-acellular-pertussis (“Tdap”) vaccines.

ii. Post-Vaccination Medical History

At 18-years old, following his freshmen year of college, petitioner joined the Army

National Guard. Pet’r Ex. 3 at 25. On May 18, 2017, petitioner received the Hepatitis A and

Hepatitis B (“Twinrix”), influenza (“Flu”), inactivated polio (“IPV”), meningococcal

(“MCV4P”), and tetanus-diphtheria-acellular-pertussis (“Tdap”) vaccines. Pet’r Ex. 3 at 19,25.

Three days later, on May 20, 2017, petitioner was sent to the emergency department

(“ED”) at Baptist Hospital for “possible psychosis.” Pet’r Ex. 11 at 9; Pet’r Ex. 16 at 3. As part

of the diagnostic work-up, a CBC was ordered. Id. at 221. Petitioner’s platelets were measured

as “low” at 94 K/ul. Id. at 221. Petitioner’s platelets were measured again on May 22, 2017 at

the VA Hospital, and were 77 K/ul. Pet’r Ex. 4 at 194. Petitioner was transferred to Richland

Springs Hospital for evaluation regarding his CBC. Pet’r Ex. 4 at 238. While awaiting a transfer

to a psychiatric department, the attending physician wrote, “Plan was to send [patient] to Three

Rivers as patient is military, but CBC showed thrombocytopenia (94). Awaiting result of repeat

CBC. Unexplained thrombocytopenia in the face of other normal lab results is unlikely to

indicate any change in medical work-up or treatment.” Id. (emphasis added).

Petitioner was hospitalized at Richland Springs until May 31, 2017. See Pet’r Ex. 4 at

239-42; Pet’r Ex. 5 at 42. During his time at Richland Spring Hospital, repeat CBCs showed his

platelet counts as follows:

4

Date Level

5/22/2017 100

5/23/2017 108

5/25/2017 109

5/27/2017 108

5/31/2017 100

Pet’r Ex. 4 at 613-15. Petitioner was discharged from Richland Springs to Eisenhower Army

Medical Center on May 31, 2017. The discharge summary on May 31, 2017 explained, “CBC

was monitored during his hospitalization. His…CBC on 5/25/2017 which revealed platelets of

109…A re-check of platelets on 05/27/2017 revealed platelets levels of 108.” Pet’r Ex. 4 at 240.

Petitioner was not provided any treatment for his low platelets. Petitioner was transferred to an

in-patient psychiatric care at an Army Medical Center, where he remained for another two

weeks. See generally Pet’r Ex. 5. Upon admission, it was noted that his platelets were “108-

stable.” Id. at 70. During this hospitalization, his platelet levels were as follows:

Date Level

6/1/2017 94

6/3/2017 81

6/4/2017 77

6/12/2017 89

Pet’r Ex. 5 at 14, 17, & 20. Again, petitioner was not treated for his low platelet levels.

After his discharge, petitioner was separated from the Army and returned thome to Texas.

He had a follow-up appointment with Dr. Hussey on June 21, 2017. Pet’r Ex. 2 at 15-18. Under

“Physical Exam” Dr. Hussey wrote that petitioner had a “history of thrombocytopenia,” and

petitioner’s physical examination was normal. Id. at 17. Dr. Hussey diagnosed petitioner with

“acquired thrombocytopenia,” and also referred petitioner to neurologist, Dr. Akhavi. The CBC

from June 21, 2017 revealed petitioner had a platelet level of 102, which was marked as “below

low normal.” Id. at 111.

On July 13, 2017, petitioner went to the emergency department of Methodist Charlton

Medical Center, for “lack of sleep” which was “less than 8 hours in the past week,” and “sleep

deprivation psychosis.” Pet’r Ex. 9 at 12. His CBC on July 13, 2017 demonstrated a platelet

count of 126 K/ul. Id. at 8. Petitioner was again admitted to inpatient psychiatric care until July

21, 2017. Pet’r Ex. 75-78. Upon discharge, it was noted that “low platelets identified but no

improvement with improved sleep wake cycle,” but no additional treatment was provided for his

noted low platelets.

On July 27, 2017, petitioner was evaluated by hematologist, Dr. Korie Flippo. Pet’r Ex.

10 at 80. Under the “History of Present Illness” it provides that petitioner is a “19 year-old

gentleman, who is noted to be thrombocytopenic over [these] last several months. His father is

also thrombocytopenia….three days after he received multiple vaccinations and he has been on

leave since that time. He denies any bruising or bleeding. They diagnosed him with a sleep

5

deprivation psychosis.” Id. (emphasis added). Family history was recorded as “father has blood

clots and has thrombocytopenia.” Id. Petitioner’s platelets were recorded as “86,000.” Id. at 81.

Dr. Flippo wrote, “No evidence of DIC.” Dr. Flippo continued to monitor petitioner’s platelet

levels. See generally Pet’r Ex. 10.

Petitioner’s lab work did not reveal anti-platelet antibodies and his bone marrow biopsy

was normal. Pet’r Ex. 10 at 45. Dr. Flippo did not recommend any specific treatment for

petitioner’s low platelets, aside from monitoring and follow-up. See e.g. Pet’r Ex. 10 at 45

(“Assessment and Plan: Thrombocytopenia—we would continue to monitor and recommend

follow up on his platelets.”).

At an appointment with Dr. Flippo on January 5, 2018, petitioner was referred to UT

Southwestern for a second opinion regarding his low platelets. Pet’r Ex. 10 at 34. Petitioner

reported increased sleeping. Id. At this appointment petitioner’s platelets were 86,000. Id. at

35.

On July 27, 2018, a year later, petitioner had an appointment with Dr. Yu Min Paul Shen

at UT Southwestern. Pet’r Ex. 10 at 119. Petitioner went to the appointment with his father and

reported that three days after he received a panel of vaccinations, his platelet levels were

discovered as “low.” Id. Petitioner reported that in the past 5-6 months his platelet levels were

just above 100,000, but he had no bleeding symptoms such as gum bleeding, nose bleeding, or

blood in his urine. Id. Petitioner reported “occasional nose bleeds associated with sinus

congestion” and he works out regularly and never has a problem with bleeding. Id. Dr. Shen’s

impression was that petitioner had “persistent but mild thrombocytopenia,” and he even noted

that petitioner had a platelet level of 92,000 in September 2015. Id. at 122. Dr. Shen also wrote

that petitioner’s more likely explanation of his low platelet count was “chronic immune

thrombocytopenia,” which is a “diagnosis of exclusion after an extensive search for alternative

causes of thrombocytopenia.” Id. at 123. He continued, stating, “even though the antiplatelet

antibody test was noted to be negative and Dr. Flippo’s note, it does not rule out the possibility

of chronic immune thrombocytopenia.” Id. Dr. Shen stated, “It is highly conceivable that the

vaccinations had induced autoimmune antibody to his platelets and this has improved over time.

The good thing about this is that even if he has ITP, there is no need for intervention given that

his platelet count has never been less than 50,000. Evidence-based recommendations from the

American Society of Hematology suggest that we do not treat ITP unless the platelet count is less

than 30,000 consistently.” Id. (emphasis added). Petitioner did not have any additional

appointments with Dr. Shen.

Petitioner returned to his regular hematologist, Dr. Flippo three days later and reported he

was “feeling well” and “doing much better.” Pet’r Ex. 10 at 16. He continued to see Dr. Flippo

for follow-up care and monitoring through 2020. During such appointments, his platelet levels

ranged from 114 K/ul to 89 K/ul. See Pet’r Ex. 10 at 7; Pet’r Ex. 78 at 7. At petitioner’s last

appointment on November 16, 2020, Dr. Flippo diagnosed petitioner with thrombocytopenia,

stating, “This was most likely ITP, gave him warning signs of increased bruising or bleeding.

He is currently stable.” Id. at 5.

6

b. Expert Opinions

i. Petitioner’s Expert: Dr. Edwin Forman, Hematologist

Petitioner submitted two reports from pediatric hematologist, Dr. Edwin Forman, who

opined that the vaccines petitioner received on May 18, 2017 was the causative factor for

petitioner developing immune thrombocytopenia purpura (“ITP”). Pet’r Exs. 18 at 4; Pet’r Ex.

54 at 5.

Dr. Forman explained that the diagnosis of ITP is made on clinical grounds and “the

exclusion of other conditions that can cause thrombocytopenia.” Pet’r Ex. 18 at 4. Dr. Forman

explained that approximately 2-3 days after petitioner received the six vaccinations, petitioner

“developed thrombocytopenia,” but that the platelets were “likely too high” for petitioner to

develop clinical symptoms like bleeding, ecchymosis, or petechiae. Id.

Dr. Forman stated that “familial or inherited thrombocytopenia, the platelet remains low,”

and that if petitioner had inherited thrombocytopenia, he would not have platelet counts of

150,000 or above at times. Id. Instead, he characterized petitioner’s diagnosis as “chronic ITP,”

stating that petitioner’s platelets remained less than 150,000 for over a year.

In his second report, Dr. Forman rebuts respondent’s experts’ opinions that petitioner had

familial thrombocytopenia. Pet’r Ex. 54 at 3-4. He states that petitioner’s platelet count of

197,000, which was seen in labs from September 2015 (pre-vaccination) “is rarely present” in

familial thrombocytopenia and that “there is no history or laboratory data available for

petitioner’s father,” and therefore, he cannot conclude that petitioner’s thrombocytopenia was

inherited. Id. at 3. Additionally, he noted that petitioner’s pre-vaccination transient platelet drop

was associated with a viral infection, which can cause a temporary drop in platelet count. Id.;

Pet’r Ex. 18 at 5. Dr. Forman’s opinion was that petitioner had post-vaccination ITP.

Dr. Forman opined that the vaccines petitioner received on May 18, 2017, caused him to

develop ITP through molecular mimicry. Pet’r Ex. 18 at 5-6. He stated that the exact

mechanism of ITP is not well understood, the medical literature characterizes ITP as an

autoimmune disease resulting from platelet antibody mediated destruction and impaired

megakaryocyte and platelet production. Id. at 6. Consolini et al. explains that autoantibodies

were discovered to platelets that led to their destruction, but also that later it was discovered that

abnormal T-helper cell defects could direct autoreactive B cells to produce autoantibodies. Pet’r

Ex. 26 at 3.4 Additionally, Chapter 133 of Hematology also endorses a role for cytotoxic T cells

having an effect on platelets in patients that have active ITP, but no detectable platelet

autoantibodies. Pet’r Ex. 35 at 5.5 The Cines et al. article explains that platelet antibodies are

only discovered in 60% of patients and that “it is not known whether some patients with ITP

have a central B-cell tolerance defect or whether loss of peripheral tolerance mediates acute or

4

Consolini, R. et al., The Centenary of Immune Thrombocytopenia-Part 1: Revising Nomenclature and

Pathogenesis, 4 Frontiers in Pediatr. Doi: 10.3389/fped.2016.0012 (2016). [Pet’r Ex. 26].

5

Hoffman R. et al., Hematology: Basic Principles and Practice, 6 th Ed. Elsevier Saunders (2013). [Pet’r Ex. 35].

7

chronic ITP.” Pet’r Ex. 25 at 9.6

Dr. Forman also references several case reports that describe ITP occurring after

vaccination. Pet’r Ex. 18 at 5. Arya et al. described two cases of children receiving the

diphtheria-pertussis-tetanus (“DPT”) vaccines and developing ITP afterwards. Pet’r Ex. 21 at 2.7

Arya first described an 18-month-old who received a booster DPT vaccination and then “over 72

hours” developed ecchymosis and bruising spots on his abdomen and extremities, and his platelet

count was 9,600. Id. at 1. The second patient described in the same article was a four-year old

who developed purpuric spots 8 days after receiving his first DPT vaccine. Id. at 2. The four-

year old’s platelet count was 50,000. Both children received steroids for an extended period and

still had ecchymosis and purpuric spots afterwards. Id.

Neau et al. described seven cases of ITP after the administration of the recombinant

hepatitis B vaccine. Pet’r Ex. 45.8 Neau stated that prior to the vaccination all seven patients

had normal platelet counts and that there was an average of 7 weeks before the

thrombocytopenia was discovered. Id. at 1. Nuevo et al. also wrote about a case report of a

child developing ITP after receipt of the hepatitis B vaccine. Pet’r Ex. 47 at 1.9 The author

explained that the child developed a petechial rash over her thorax, abdomen, upper and lower

extremities and her platelet count was discovered to be 11,000. Id. Nuevo also included a chart

of reported cases of ITP after hepatitis B vaccination and noted that the interval between

vaccination and onset of ITP was between 1 day to 3 months. Id. at 2. Importantly though, the

one-day onset of ITP was after the second dose of the hepatitis B vaccine. Id. at 3.

Finally, the O’Leary article, which examined pediatric ITP cases across different Kaiser

medical centers and found a “significant association of ITP with MMR” which are routinely

administered to children between ages 12 to 19 months of age. Pet’r Ex. 48 at 4.10 Additionally,

the same article found a significantly elevated risk of ITP after the hepatitis A vaccine for ages 7

to 17 and for varicella vaccine and Tdap vaccine for ages 11 to 17. Id. at 1.

Dr. Forman opined that the finding of ITP two days post-vaccination was an acceptable

medical timeframe for the vaccines petitioner received to result in ITP. Pet’r Ex. 18 at 6; Pet’r

Ex. 54 at 3. He referred to the case report described in Hamiel et al., where a child repeatedly

6

Cines, D. et al., The ITP Syndrome: Pathogenic and Clinical Diversity, 113 (26) Blood 6511-6521 (2009). [Pet’r

Ex. 25].

7

Arya L. et al., Thrombocytopenic Purpura following DPT Vaccination, 10 Pediatr. Hematol. Oncol. 381-383

(1992). [Pet’r Ex. 21].

8

Neau, D. et al., Immune Thrombocytopenic Purpura After Recombinant Hepatitis B Vaccine: Retrospective Study

of Seven Cases, 30 Scand. J. Infect. Dis. (1998). [Pet’r Ex. 45].

9

Nuevo, H. et al., Thrombocytopenic Purpura After Hepatitis B Vaccine: A Case Report and Review of the

Literature, 23 Pediatr. Infect. Dis. J. 183-184 (2004). [Pet’r Ex. 47].

10

O’Leary, S. et al., The Risk of Immune Thrombocytopenia Purpura after Vaccination in Children and Adolescents,

129 Pediatrics 248-255 (2012). [Pet’r Ex. 48].

8

developed ITP after receiving influenza vaccines. Pet’r Ex. 32 at 1.11 The authors noted that the

child developed symptoms of thrombocytopenia one week after his first dose of the flu vaccine,

then within 6 days after the second and third flu vaccines. Id. Hamiel also discussed other

articles on ITP following vaccination and stated that, “some individual reports of ITP occurring

in adults within 4 to 17 days after influenza vaccination have been published.” Id. at 3. Dr.

Forman also stated that the 7-to-10-day range of onset post-vaccination cited by respondent’s

expert was “more of a mean than a range,” and that the O’Leary and Baxter articles support a

closer in time temporal association. Pet’r Ex. 54 at 6. Dr. Forman stated that petitioner received

a high number of vaccines on May 17, 2017, and argued that it was possible that petitioner had

either been exposed or vaccinated to one or more of the viruses he was immunized against,

which would cause a faster immune response. Id.

ii. Respondent’s Expert: Dr. Michele P. Lambert12

Dr. Lambert provided two expert reports on this matter, both of which she opined that

petitioner’s thrombocytopenia was a long-standing, asymptomatic, inherited condition, and that

the vaccines petitioner received were not the cause of his thrombocytopenia. See Resp’t Ex. A at

3; Resp’t Ex. E at 3.

Dr. Lambert first explained the difference between immune thrombocytopenia (“ITP”)

and inherited macrothrombocytopenia. Resp’t Ex. A at 3-4. She explained that ITP “is

characterized by a platelet count of” less than 100,000 “in the absence of other hematologic

abnormalities and without any evidence of other underlying etiologies.” Id. Inherited

macrothrombocytopenias, on the other hand “are a group of inherited platelet disorders that are

generally associated with autosomal dominant inheritance of variants in platelet related gene that

most often impact the platelet cytoskeletal machinery.” Id. at 3-4. Dr. Lambert notes that “these

platelet disorders are rarely associated with a bleeding phenotype, are often mistaken for chronic

ITP, and are associated with a high mean platelet volume, moderate to mild thrombocytopenia,

and elevated immature platelet fraction.” Id. at 4. Dr. Lambert acknowledged that the

hematologic work of petitioner’s father was “incomplete” but she argued that petitioner’s low

but stable platelet ranges was consistent with a familial macrothrombocytopenia. Resp’t Ex. A at

4.

Dr. Lambert referenced Arnold et al., which explained that ITP’s clinical presentation can

11

Hamiel, U. et al., Recurrent Immune Thrombocytopenia After Influenza Vaccination: A Case Report, 138

Pediatrics 2-5 (2018). [Pet’r Ex. 32].

12

Dr. Lambert is a board-certified pediatrician and pediatric hematologist/oncologist. She is an Associate Professor

of Pediatrics at the University of Pennsylvania and is an attending physician at the Children’s Hospital of

Philadelphia where she is the clinical director of the Special Coagulation Laboratory, a co-director of the

multidisciplinary Immune Dysregulation Frontier Clinic, and the director of the Pediatric Platelet Disorder Program.

She is a member of the American Society of Hematology, the American Society of Pediatric Hematology/Oncology,

the International Society of Thrombosis and Haemostasis and the Hemostasis and Thrombosis Research Society.

Resp’t Ex. A at 1. Dr. Lambert earned her bachelor’s degree from Rensselaer Polytechnic Institute and her medical

degree from UMDNJ – New Jersey Medical School. Resp’t Ex. B. She completed her residency in pediatrics at St.

Christopher’s Hospital for Children and completed her fellowship in Hematology/Oncology at the Children’s

Hospital of Philadelphia. Id.

9

range of “asymptomatic thrombocytopenia to nuisance bruising to life-threatening intracranial

hemorrhage.” Resp’t Ex. A, Tab 8 at 1.13 Arnold also explains that the “diagnosis of primary

ITP, a platelet count of <100 X 10/L in the absence of an identifiable cause, is nonspecific,” and

that in their study, they had identified a subset of patients that met the standard criteria, but never

requirement treatment and their symptoms were mild. Id. at 4-5. Arnold stated that one in seven

patients suspected of ITP of having primary ITP was misdiagnosed at some point during their

disease course. Id. at 1.

Further, Dr. Lambert argued that patients with definite ITP have “extremely low platelet

counts below 20x10/L at some point in their disease course.” Resp’t Ex. E at 2. Citing Li et al,

Dr. Lambert wrote, “…in addition, 42.7% of patients with suspected ITP17 exhibited severe

thrombocytopenia. Comparatively, only 10.5% of patients with non-immune thrombocytopenia

exhibited severely low platelet counts.” Id.; see also Resp’t Ex. A, Tab 6.14 Dr. Lambert noted

that petitioner’s platelet count was fairly uniform, and at times rose above 100K, which is more

consistent with a long-standing asymptomatic congenital thrombocytopenia. Resp’t Ex. E at 2.

iii. Respondent’s Expert-Dr. Ross Kedl

Respondent also submitted an expert report from Dr. Ross Kedl, an immunologist.

Resp’t Ex. C. Dr. Kedl opined that the vaccines petitioner received on May 18, 2017 did not

cause him to develop ITP and that Dr. Forman’s opinion is based on identifying the nearest

preceding event—the vaccinations—as the cause. Id. at 2. Dr. Kedl agrees with Dr. Lambert

that petitioner did not have immune-mediated thrombocytopenia, but instead “idiopathic”

thrombocytopenia. Id. at 4.

With respect to Dr. Forman’s opinion regarding the mechanism for which the vaccines

could cause ITP, Dr. Kedl argues that Dr. Forman does not provide any homology between any

of the vaccines the petitioner received and platelet antigens. Resp’t Ex. C at 5. Most relevant to

this case and to the dispositive issue in this matter, Dr. Kedl states that the onset of 2 days post-

vaccination is “insufficient” for the theory of molecular mimicry. Id. He states that a 7–10-day

onset of symptoms of thrombocytopenia is “generally accepted as necessary for the activation

and expansion of an adaptive immune response to any vaccination or infectious challenge.” Id.

IV. Analysis and Conclusion

The parties agree that petitioner suffers from thrombocytopenia. See Resp’t Br. at 10;

Pet’r Br. at 3. Instead, they mostly disagree about the underlying cause of petitioner’s condition,

with Dr. Forman arguing that petitioner suffers from chronic immune thrombocytopenia, and Dr.

Lambert opining petitioner has a congenital form of thrombocytopenia. See Pet’r Ex. 18 at 6;

Resp’t Ex. A at 4; Resp’t Ex. E at 2. Respondent agrees that petitioner’s thrombocytopenia

13

Arnold, D. et al., Misdiagnosis of Primary Immune Thrombocytopenia and Frequency of Bleeding: Lessons from

the McMaster ITP Registry, 1(25) Blood Advances 2414-2420 (2017). [Resp’t Ex. A, Tab 8].

14

Li, N. et al., Platelet Variability Index: A Measure of Platelet Count Fluctuations in Patients with Immune

Thrombocytopenia, 5(20) Blood Advances 4256-4264 (2021). [Resp’t Ex. A, Tab 6].

10

is “chronic” as it is long-standing, but it is not acute. Ultimately, this conflict goes to the role of

the vaccines petitioner received on May 18, 2017, in the development of his condition. Further,

this case turns on a much simpler issue: when petitioner’s ITP began in relation to his

vaccinations.

As discussed below, petitioner has failed to provide preponderant evidence to satisfy

Althen prongs two and three.

a. Althen prong one

Dr. Forman argued that the most likely mechanism for which the vaccines petitioner

received could cause ITP was molecular mimicry. Pet’r Ex. 18 at 6; Pet’r Ex. 54 at 4

(“Molecular mimicry is repeatedly cited as a mechanism for causing ITP after vaccination.” He

also notes that in several of the case reports, the vaccines the patients received “were causal

rather than coincidental.” Pet’r Ex. 54 at 4; see e.g. Pet’r Ex. 32 at 4 (“The cause of ITP remains

unknown in most cases, but it can be triggered by a viral infection or other immune triggers, such

as vaccinations, most likely by the mechanism of molecular mimicry.”). The medical articles

and numerous case report articles does support molecular mimicry as a possible causal

mechanism of post-vaccination ITP. See Pet’r Exs. 43 at 2; Pet’r Ex. 25 at 8; Pet’r Ex. 29 at 2.

Further, the undersigned, as well as other special masters, have accepted the theory of molecular

mimicry as a causal mechanism for ITP following vaccination. See Mitchell v. Sec’y of Health &

Hum. Servs., No. 19-1534V, 2023 WL 4483134 (Fed. Cl. Spec. Mstr. Jan. 11, 2023) (accepting

the flu vaccine can cause ITP through the mechanism of molecular mimicry); Walls v. Sec’y of

Health & Hum. Servs., No. 16-557V, 2020 WL 13801342, at *15-16 (Fed. Cl. Spec. Mstr. June

23, 2020) (accepting molecular mimicry as the mechanism for the DtaP, Hib, Hep B & PCV

vaccines to cause ITP); Phillips v. Sec’y of Heath & Hum. Servs., No. 16-906V, 2020 WL

7767511, at *25 (Fed. Cl. Spec. Mstr. Nov. 23, 2020) (accepting molecular mimicry between the

HPV vaccine and ITP, denying on other grounds); Johnson v. Sec’y of Health & Hum. Servs.,

No. 14-113V, 2017 WL 772534 (Fed. Cl. Spec. Mstr. Jan. 6, 2017) (accepting molecular

mimicry as a causal mechanism between ITP and the HPV vaccine); Ebenstein v. Sec’y of Health

& Hum. Servs., No. 06-573V, 2010 WL 5113185, at *2 (accepting molecular mimicry links the

MMR vaccine and ITP).

Petitioner received multiple vaccines on May 18, 2017, some of which were implicated in

the case reports cited by Dr. Forman as a causal link to ITP and epidemiological evidence is not

necessary for petitioner to establish Althen prong one. Thus, the undersigned will accept Dr.

Forman’s theory of molecular mimicry as the mechanism to explain how the flu, hepatitis A and

B vaccine, IPV, meningococcal, and Tdap can cause ITP.

However, the fatal issue to petitioner’s claim lies with the onset of his thrombocytopenia

and then subsequent clinical course.

b. Althen prong three

Petitioner has failed to demonstrate the onset of his chronic thrombocytopenia began

within an appropriate timeframe given the proposed mechanism of molecular mimicry.

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Petitioner received the IPV, Tdap, Twinrix, meningococcal, and flu vaccinations on May

18, 2017. Two days later, on May 20, 2017, he was hospitalized for a mental health illness and

his low platelet level was found during this admission. See Pet’r Ex. 11 at 221. Petitioner did

not report any other symptoms possibly related to thrombocytopenia, such as petechiae or

bruising.

Dr. Forman opined that a 2-3 day timeframe between vaccinations and thrombocytopenia

is generally accepted to infer vaccine causation. Important to the third Althen prong is that “the

explanation for what is a medically acceptable time frame must also coincide with the theory of t

vaccine causation of the injury alleged (under Althen prong one). De Bazan, 539 F.3d at 1352.

A temporal relationship between a vaccine and an injury standing alone does not constitute

preponderant evidence of vaccine causation. See e.g. Veryzer, 100 Fed. Cl. at 356 (explaining

that “a temporal relationship alone will not demonstrate the requisite causal link and that

petitioner must posit a medical theory causally connecting the vaccine and injury”), aff’d 475 F.

App’x 765 (Fed. Cir. 2012). Accepting petitioner’s theory of molecular mimicry between the

vaccines and ITP, the onset of petitioner’s symptoms needs to fall within a relevant timeframe

consistent with that theory. This is where the onset of 2-3 days in petitioner’s case fails.

Importantly, most of the medical literature filed in this case, including articles by

petitioner, invoke a later onset of ITP post-vaccination than two days. The Hamiel case report

Dr. Forman cited explained that the onset of ITP symptoms after the child patient received the

flu vaccine on three separate occasions began 6-7 days post-vaccination. Pet’r Ex. 32 at 2. The

Neau article describes cases of ITP occurring after the recombinant hepatitis B vaccine occurring

between 2 weeks to three months after vaccination. Pet’r Ex. 45 at 2. The Nagasaki article,

which describes three elderly patients developing ITP symptoms after receiving the flu vaccine

had first symptoms occurring within four weeks of the vaccination. Pet’r Ex. 43 at 3.15

Similarly, the Casoli case report described a patient developing ITP symptoms 15 days after

receiving the flu vaccine. Pet’r Ex. 23 at 1. The Vlacha article, which describes a case of a

pediatric patient developing recurrent thrombocytopenia after repeated MMR vaccines indicated

that onset of his symptoms occurred 19- and 23-days post-vaccination. Pet’r Ex. 73 at 2.16

Moreover, the cases in the Vaccine Program in which molecular mimicry has been

invoked as the causal mechanism for ITP, the onset of the symptoms of those petitioners is later

than 2-3 days. For example, in Walls, the onset of petitioner’s ITP’s symptoms was found to be

nine days post-vaccination. Walls, 2020 WL 13801342, at *21. The petitioner in Mitchell

developed symptoms of ITP 35-days after the flu vaccine, which the Special Master found to be

consistent with mechanism of molecular mimicry. Mitchell, 2023 WL 4483134, at *27.

While some of the case reports do note a more rapid onset of symptoms following repeat

vaccinations, suggesting a challenge-rechallenge circumstance, there is not sufficient evidence to

15

Nagasaki, J. et al., Post-influenza Vaccination Idiopathic Thrombocytopenic Purpura in Three Elderly Patients,

Case Rep Hematol. 2016:7913092 (2016). [Pet’r Ex. 43].

16

Vlacha, V. et al., Recurrent Thrombocytopenia After Repeated Measles-Mumps-Rubella Vaccination, 97(5)

Pedatr. 738-39 (1996). [Pet’r Ex. 73].

12

demonstrate that petitioner had previously received any of the vaccines he had received on May

18, 2017 or that he had developed any specific immune response to viruses against which the

vaccines are meant to protect. In fact, prior to his vaccination, it was noted that petitioner was

“negative” for antibodies to the hepatitis A and B virus. See Pet’r Ex. 3 at 20 (“Hepatitis A

Virus Ab-Negative (Not Immune); Hepatitis B Virus Surface Ab-Negative (Susceptible)”). No

medical records were filed to indicate that petitioner had previously received any of the vaccines

in question. Thus, the evidence does not support a challenge-rechallenge or recall response

which could explain an earlier onset than would be expected based on molecular mimicry in the

adaptive immune response. The literature supports a longer period of onset as in Vlacha, Nuevo,

and Kelton articles.

Accordingly, petitioner has failed to demonstrate by preponderant evidence that the onset

of his chronic thrombocytopenia two days post-vaccination is a medically acceptable timeframe

consistent with the theory of molecular mimicry.

c. Althen prong two

As petitioner has failed to demonstrate that the onset of his idiopathic thrombocytopenia

two days post-vaccination was a medically appropriate timeframe under Althen prong three, he

cannot demonstrate a logical sequence of cause and effect as required by 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). While Althen

prong one requires a petitioner to show that the vaccine can cause the underlying condition,

under prong two he or she must show that the vaccine did cause the condition in his or her

specific case. Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1356 (Fed. Cir. 2006).

While it is true that petitioner’s low platelet level was found two days after his

vaccination, it does not establish that the vaccines he had received were the actual cause for the

illness. Additionally, petitioner’s clinical course and treatment—or lack thereof—was

inconsistent with immune mediated thrombocytopenia after vaccination as described in the

medical literature. Indeed, given his lack of symptoms, his relatively mild and stable platelet

counts, and the noted thrombocytopenia in his father, it appears more likely that an underlying

mild thrombocytopenia was incidentally discovered after the vaccinations but was not caused by

them.

For example, the Arya article described two cases of pediatric patients who developed

nosebleeds and purpuric spots approximately three and eight days after receiving booster doses

of DPT vaccines. Pet’r Ex. 21 at 1. Further, the platelet levels in the pediatric patients were

found to be between 30,000 and 50,000 and they were treated with steroids for multiple weeks.

Id. The Kelton article described a patient who developed purpura and hemoptysis two weeks

after the flu vaccine, and his platelets were 20,000. Pet’r Ex. 64 at 1.17 This patient was treated

with steroids until his platelet level normalized. When the same patient received the

17

Kelton, J., Vaccination-Associated Relapse of Immune Thrombocytopenia, 245 JAMA 369-371 (1981). [Pet’r Ex.

64].

13

pneumococcal vaccine one year later, he developed purpura and nose bleeds two weeks after

vaccination and his platelet level was 32,000. Id. The Vlacha case report describes a pediatric

patient that developed petechiae and bruising 23 days after receiving the third dose of the MMR

vaccine. Pet’r Ex. 73. The patient’s platelet level was 10,000 and he was treated with steroids

for multiple weeks. Id. And while the Nagasaki article did report on an elderly patient

developing thrombocytopenia without any other associated symptoms, the onset of the

thrombocytopenia was four weeks post-vaccination and her platelet level was 39,000, requiring

treatment. Pet’r Ex. 43 at 1.

In petitioner’s case, he did not have any associated symptoms of immune

thrombocytopenia, such as bruising, nosebleeds, or bleeding gums prior to the onset of his low

platelet levels, as described in the case reports above. Further, the platelet levels of the patients

in the case reports were far lower than petitioner’s on initial blood draws and they all required

some type of treatment. As Dr. Lambert noted in her reports, petitioner’s stable and relatively

high platelet count makes much more likely that petitioner’s thrombocytopenia was inherited and

not immune mediated. Resp’t Ex. A at 4; Resp’t Ex. E at 2. Given the stark contrast between

petitioner’s presentation and the cases describing immune thrombocytopenia purpura, and the

lack of treatment, there is not sufficient evidence to support a logical sequence of cause and

effect between the vaccines petitioner received and his idiopathic thrombocytopenia.

Accordingly, petitioner is unable to demonstrate by preponderant evidence Althen prong

two.

V. Conclusion

After a careful review of the record, petitioner has failed to provide preponderant

evidence that the vaccines he received on May 17, 2017, caused him to develop idiopathic

chronic thrombocytopenia. Accordingly, petitioner’s claim is hereby DISMISSED.

IT IS SO ORDERED.

s/Thomas L. Gowen

Thomas L. Gowen

Special Master

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