Defenza v. Secretary of Health and Human Services

In the United States Court of Federal Claims

STACY L. DEFENZA as administrator of

ESTATE OF LINDA L. CHERVENOK,

Petitioner,

No. 18-1601

v. (Filed Under Seal: May 29, 2026)

(Reissued Publicly: June 16, 2026)

SECRETARY OF HEALTH AND

HUMAN SERVICES,

Respondent.

Jeffrey S. Pop, Kristina E. Grigorian, Jeffrey S. Pop & Associates, Beverly Hills,

California, for Petitioner.

Nina Y. Ren, Trial Attorney, Julia M. Collison, Assistant Director, Heather L. Pearlman,

Deputy Director, Jonathan D. Guynn, Acting Director, Torts Branch, Brett A. Shumate,

Assistant Attorney General, Civil Division, United States Department of Justice,

Washington, DC, for Respondent.

OPINION AND ORDER1

HADJI, Judge.

Petitioner seeks review of a decision denying her petition for compensation under

the National Vaccine Injury Compensation Program. For the reasons stated below,

Petitioner’s Motion for Review (ECF 109) is DENIED, and the Special Master’s Decision

(ECF 107) is SUSTAINED.

BACKGROUND

I. Petitioner’s Medical History

The underlying facts set forth in Petitioner’s medical records are few and

undisputed. Accordingly, the Court adopts such facts as set forth in the Special Master’s

Decision and briefly recounts them here.

1

This Opinion was issued under seal on May 29, 2026. The parties were directed to propose redactions by

June 12, 2026. No proposed redactions were received. The Court hereby publicly releases the Opinion and

Order in full.

On October 21, 2015, Petitioner Linda L. Chervenok received a flu vaccination.2

ECF 107 at 5. The next day, she began experiencing shortness of breath, numbness,

tingling, and flaccid paralysis in her extremities. Id. Petitioner was ultimately diagnosed

with Guillain-Barre Syndrome (GBS). Id.

Petitioner’s October 2015 flu vaccination was not her first; she had previously

received flu vaccinations, including some that contained H1N1 components. Id. at 6.

Petitioner also suffered from chronic lower back pain. Id. On October 8, 2015,

approximately two weeks prior to the vaccination at issue, Petitioner underwent a

radiofrequency ablation procedure to treat this condition. Id.

II. The Petition and Procedural History

On October 16, 2018, Petitioner filed a petition for compensation under the National

Vaccine Injury Compensation Program, 42 U.S.C. §300aa-10, et seq.,3 alleging that her

October 2015 flu vaccine caused her to develop GBS. ECF 1 at 1. In support of her claim,

Petitioner submitted medical records, affidavits, and an opinion letter from her treating

neurosurgeon, Allison Rathmann, D.O. See ECF 9, 13, 37. Respondent submitted his Rule

4(c) Report, which primarily argued that the petition should be dismissed due to the 24-

hour post-vaccination period of onset. See generally ECF 29. In response, Petitioner

submitted an expert report by neuroimmunologist Lawrence Steinman, M.D., along with

supporting medical literature. See generally ECF 34-1, 37. Dr. Steinman opined that the

flu vaccine can cause GBS within 24 hours via molecular mimicry and that a recall

antibody response due to prior flu vaccinations can manifest within 24 hours. ECF 34-1 at

1.

Disputing causation, Respondent filed a responsive expert report and supporting

medical literature by immunologist J. Lindsay Whitton, M.D., Ph.D. See generally ECF

43-1. Dr. Whitton characterized Dr. Steinman’s theories of molecular mimicry as “deeply

flawed” and challenged his opinion that molecular mimicry can lead to disease within 24

hours, even in the context of a recall response. Id. at 26.

Following review of Drs. Steinman and Whitton’s expert reports, the Special Master

issued a Rule 5 Order expressing skepticism that Petitioner could meet her burden of proof

under the three-prong test articulated in Althen v. Secretary of Health & Human Services,

which requires petitioners, in relevant part, to establish a “proximate temporal relationship”

between the vaccination and the injury alleged. 418 F.3d 1274, 1278 (Fed. Cir. 2005); see

ECF 44 at 1. Recognizing that much of the reasoning in Dr. Steinman’s expert report

regarding onset had been previously rejected by another special master, the Special Master

2

Petitioner Linda L. Chervenok passed away in April 2025. ECF 103-1. Her daughter, Stacy L. DeFenza,

has been substituted for Petitioner as estate administrator. See ECF 109 at 6; see also Docket, Case No. 18-

1601.

3

The National Vaccine Injury Compensation Program was established by the National Childhood Vaccine

Injury Act of 1986, Pub. L. No. 99-660, 100 Stat. 3755 (the Vaccine Act).

2

recommended that Petitioner strongly consider the voluntary dismissal of her claim. ECF

44 at 1-2 (citing Rowan v. Sec’y of Health & Hum. Servs., No. 17-760, 2020 WL 2954954

(Fed. Cl. Spec. Mstr. Apr. 28, 2020)). Rather than do so, Petitioner submitted a

supplemental expert report from Dr. Steinman, focused on the timing of onset. See

generally ECF 46-1. Respondent countered with a responsive supplemental report by Dr.

Whitton. See generally ECF 51-1. Petitioner and Respondent each filed an additional

supplemental expert report, through which they continued to offer divergent opinions on

the significance of the short interval between Petitioner’s vaccination and the onset of GBS.

See generally ECF 53-2; 55-1. Petitioner also filed a second opinion letter by her treating

neurosurgeon. See generally ECF 53-1. The letter noted that “no other cause for

[Petitioner’s] GBS was identified following a robust work up,” and described two pieces

of medical literature that discussed the timing of onset of GBS following a flu vaccine,

both of which Dr. Rathmann claimed supported a 1-2 day interval between flu vaccination

and GBS. Id. at 1. Dr. Rathmann also reasserted her belief that the flu vaccination was

more likely than not the cause of Petitioner’s GBS, though she “defer[red] to a neurologist

or immunologist on how biologically this can occur.” Id.

In the lead up to the entitlement hearing, the parties both filed additional evidence,

including updated medical records and medical literature. See ECF 60, 61, 64, 66, 67, 68,

70, 71, 72. As relevant here, Petitioner ultimately introduced several epidemiological

studies, which she contended provide support for the proposition that the flu vaccine can

cause GBS within one day. These studies include the Schonberger,4 Salmon,5 Polakowski,6

and Park7 studies. See ECF 36-5 (Schonberger); ECF 47-2 (Salmon); ECF 68-4

(Polakowski); ECF 47-1 (Park). All four studies observed cases of GBS occurring within

two days of vaccination. See ECF 107 at 19, 22-23. As described by the Special Master,

the Schonberger study is a surveillance study conducted following a 1976 mass vaccination

campaign. Id. at 19. It is generally accepted as providing support for the proposition that

the flu vaccine can cause GBS and indicates that incidence of GBS was elevated relative

to the first full week post-vaccination. Id. at 19-20. The Salmon and Polakowski studies

were likewise conducted following a mass vaccination campaign, this time in 2009. Id. at

21. The Salmon study meta-analyzed an exposure window of 1-42 days and confirmed that

first week results were statistically significant. Id. at 22. The Polakowski study, which

examined chart-confirmed cases of GBS, similarly considered a risk period of 1-42 days.

Id. It found an elevated risk of GBS for the six-week period following vaccination. Id. And

4

Lawrence B. Schonberger et al., Guillain-Barre Syndrome Following Vaccination in the National

Influenza Immunization Program, United States, 1976-1977, 110 AM. J. EPIDEMIOLOGY 105 (1979).

5

Daniel A. Salmon et al., Association Between Guillain-Barre Syndrome and Influenza A (H1N1) 2009

Monovalent Inactivated Vaccines in the USA: A Meta-Analysis, 381 LANCER 1461 (2013).

6

Laura L. Polakowski et al., Chart-Confirmed Guillain-Barre Syndrome After 2009 H1N1 Influenza

Vaccination Among the Medicare Population, 2009-2010, 178 AM. J. EPIDEMIOLOGY 962 (2013).

7

Yong-Shik Park et al., Clinical Features of Post-Vaccination Guillain-Barre Syndrome (GBS) in Korea,

32 J. KOREAN MED. SCI. 1154 (2017).

3

finally, the Park study examined the demographic characteristics of GBS patients who

sought compensation from South Korea’s version of the Vaccine Program. Id. at 23. In that

study, half of all examined cases developed symptoms within two days of vaccination. Id.

On March 4-5, 2024, the Special Master held an entitlement hearing, where both

experts testified. See ECF 92, 93. Following the hearing, both parties filed post-trial

supplemental expert reports and post-hearing briefs. See generally ECF 95, 97-1, 98-1, 99,

100, 102.

On January 7, 2026, the Special Master issued his Decision. ECF 107. The Special

Master found that “there is no dispute that the onset of [Petitioner]’s GBS occurred about

24 hours post-vaccination,” and focused on what he characterized as the “core dispute” in

this case: “whether that period of onset is appropriate for a causal inference based on Dr.

Steinman’s theory of causation, which is based on molecular mimicry.” Id. at 9.

The Special Master answered that question in the negative. Deeming the testimony

of Respondent’s expert, Dr. Whitton, more persuasive than that of Petitioner’s expert, Dr.

Steinman, the Special Master found that “Dr. Steinman has not come forward with a

preponderantly supported explanation of how [P]etitioner’s flu vaccine could have

produced an autoantibody response leading to a loss of immune self-tolerance and

subsequent development of GBS within 24 hours of vaccination.” Id. at 18. Regarding the

studies cited by Dr. Steinman, the Special Master determined that they “are not entirely

lacking teachings potentially supportive of [P]etitioner’s view,” but “they do not ultimately

add significantly to [P]etitioner’s claim,” given their respective weaknesses and

limitations. Id. at 18-19. In particular, he found that the Schonberger, Salmon, and

Polakowski studies did not include any calculations to support excess risk of GBS on Day

1, even though the studies technically expressed the period of elevated risk in a manner

that did not exclude Day 1. See id. at 19-23. Crediting Dr. Whitton’s testimony that

approximately five cases of GBS are expected each day purely as a result of chance, the

Special Master further found that “one or two cases of GBS occurring on any given day

could be the result of chance, greatly tempering the potential significance” of the Salmon

and Polakowski studies, which each observed less than five cases on Day 1. Id. at 23. With

respect to the Park study, the Special Master determined it was “difficult to draw any

conclusions from this study” as it observed “a highly selective group” of people seeking

compensation for perceived vaccine injury under South Korea’s vaccine injury

compensation program and “we do not have information on what criteria the compensating

authority uses to adjudge eligibility.” Id. at 23. More broadly, the Special Master found

that “epidemiologic data is limited to demonstrating correlation, rather than causation,”

and weighed Petitioner’s epidemiological studies accordingly. Id. at 20. Ultimately, the

Special Master concluded that “the onset of [Petitioner]’s GBS occurred too soon after

vaccination to be causally related.” Id. at 26 (emphasis omitted).

On February 5, 2026, Petitioner timely filed a Motion for Review. ECF 109.

Respondent filed his Memorandum in Response the following month. ECF 112.

4

STANDARD OF REVIEW

Under the Vaccine Act, this Court has jurisdiction to review a special master’s

entitlement decision. 42 U.S.C. § 300aa-12(e)(2). In reviewing a special master’s decision,

this Court may:

(A) uphold the findings of fact and conclusions of law of the

special master and sustain the special master’s decision, (B) set

aside any findings of fact or conclusion of law of the special

master found to be arbitrary, capricious, an abuse of discretion,

or otherwise not in accordance with law and issue its own

findings of fact and conclusions of law, or (C) remand the

petition to the special master for further action in accordance

with the court’s direction.

42 U.S.C. § 300aa-12(e)(2)(A)-(C). The standards set forth in 42 U.S.C. § 300aa-

12(e)(2)(B) “vary in application as well as degree of deference” as “[e]ach standard applies

to a different aspect of the judgment.” Munn v. Sec’y of Health & Hum. Servs., 970 F.2d

863, 870 n.10 (Fed. Cir. 1992). Findings of fact receive deferential review under the

“arbitrary and capricious” standard; legal conclusions are reviewed de novo under the “not

in accordance with law” standard; and discretionary rulings are reviewed for “abuse of

discretion.” Turner v. Sec’y of Health & Hum. Servs., 268 F.3d 1334, 1337 (Fed. Cir. 2001).

With respect to the arbitrary and capricious standard, “no uniform definition … has

emerged,” but it is “a highly deferential standard of review” such that “[i]f the special

master has considered the relevant evidence of record, drawn plausible inferences and

articulated a rational basis for the decision, reversible error will be extremely difficult to

demonstrate.” Hines v. Sec’y of Health & Hum. Servs., 940 F.2d 1518, 1527-28 (Fed. Cir.

1991); see also Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto Ins. Co.,

463 U.S. 29, 43 (1983) (A decision is arbitrary and capricious only if it is “so implausible

that it could not be ascribed to a difference in view….”). Accordingly, if a special master’s

finding of fact is “based on evidence in the record that [is] not wholly implausible,” this

Court is “compelled to uphold that finding as not being arbitrary or capricious.” Lampe v.

Sec’y of Health & Hum. Servs., 219 F.3d 1357, 1363 (Fed. Cir. 2000).

The “not in accordance with law” standard, on the other hand, is applied without

deference to legal determinations, such as “[w]hether the special master applied the

appropriate standard of causation . . . .” Deribeaux v. Sec’y of Health & Hum. Servs., 717

F.3d 1363, 1366 (Fed. Cir. 2013). Lastly, the abuse of discretion standard applies to the

special master’s discretionary rulings, such as evidentiary determinations regarding the

qualification of experts and the admissibility of their testimony. Piscopo v. Sec’y of Health

& Hum. Servs., 66 Fed. Cl. 49, 53 (2005). Determinations subject to review for abuse of

discretion must be sustained unless “manifestly erroneous.” Id.; see also Milmark Servs.,

Inc. v. United States, 731 F.2d 855, 860 (Fed. Cir. 1984).

5

DISCUSSION

Under the Vaccine Act, petitioners bear the burden of proving, by a preponderance

of the evidence, that a vaccine caused an injury or death. 42 U.S.C. § 300aa-13(a)(1); 42

U.S.C. § 300aa-11(c)(1)(C); Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352,

1355 (Fed. Cir. 2006). The Federal Circuit has “interpreted the ‘preponderance of the

evidence’ standard referred to in the Vaccine Act as one of proof by a simple

preponderance, of ‘more probable than not’ causation.” Althen, 418 F.3d at 1279. In

considering the evidence, special masters are required to consider “the record as a whole.”

42 U.S.C. §300aa-13(a)(1). Because “the purpose of the Vaccine Act’s preponderance

standard is to allow the finding of causation in a field bereft of complete and direct proof

of how vaccines affect the human body,” Althen, 418 F.3d at 1280, proof of medical

certainty is not required, Bunting v. Sec’y of Health & Hum. Servs., 931 F.2d 867, 873

(Fed. Cir. 1991).

There are two methods by which a petitioner may establish causation and thus

eligibility for compensation. Munn, 970 F.2d at 865. Through the first method, a petitioner

may demonstrate causation through a statutorily prescribed presumption by showing that

the alleged injury meets the criteria listed on the Vaccine Injury Table, as set forth in 42

U.S.C. § 300aa-14 and 42 C.F.R. § 100.3. Id. The Table identifies the covered vaccines,

the corresponding injuries, and the time period after vaccination in which the particular

injuries must occur. 42 C.F.R. § 100.3. “[I]f a petitioner can establish that [he] received a

listed vaccine and experienced such symptoms or injuries within the specified timeframes,

[he] has met [his] prima facie burden to prove that the vaccine caused [his] injuries.” de

Bazan v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1351 (Fed. Cir. 2008).

Alternatively, petitioners who have suffered an “off-Table injury,” meaning their injury

does not meet the criteria in the Table, must use the second method to prove causation.

This method requires a petitioner to prove “causation-in-fact” by a preponderance of the

evidence. See 42 U.S.C. § 300aa-11(c)(1)(C)(ii)(II), 42 U.S.C. § 300aa-13(a)(1); see also

Broekelschen v. Sec’y of Health & Hum. Servs., 618 F.3d 1339, 1341-42 (Fed. Cir. 2010).

“Once causation is established, the petitioner is entitled to compensation unless the

Government can show by a preponderance of the evidence that the injury is due to factors

unrelated to the vaccine, i.e., an alternative cause.” Porter v. Sec’y of Health & Hum. Servs.,

663 F.3d 1242, 1249 (Fed. Cir. 2011).

In the present case, Petitioner alleged that a flu vaccination caused her to suffer

GBS. ECF 1 at 1. Although the Vaccine Injury Table lists GBS as a presumptive vaccine

injury following the flu vaccine, onset of symptoms must occur “not less than 3 days and

not more than 42 days” following vaccination for it to be considered a Table injury. See 42

C.F.R. § 100.3(a). Because Petitioner’s onset of symptoms did not begin within the

timeframe listed on the Table, Petitioner concedes that she is not entitled to a presumption

of causation and that she must thus establish causation-in-fact. ECF 109 at 9.

Under the three-prong test articulated by the Federal Circuit in Althen, proving

causation-in-fact requires a showing of: (1) a medical theory causally connecting the

6

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 proximate temporal relationship

between vaccination and injury. 418 F.3d at 1278. Although a petitioner need not show

that her vaccination was the sole cause of her injury, she must demonstrate that “the vaccine

was not only a but-for cause of the injury but also a substantial factor in bringing about the

injury.” Shyface v. Sec’y of Health & Hum. Servs., 165 F.3d 1344, 1352 (Fed. Cir. 1999).

“[C]lose calls regarding causation are resolved in favor of injured claimants.” Althen, 418

F.3d at 1280.

In the instant case, the Special Master found that Petitioner did not meet her burden

in establishing causation-in-fact. See ECF 107 at 26. Petitioner contends the Special Master

erred in four main ways. Specifically, she claims that he: (1) conflated requirements for

Althen prong 1 in his assessment of Althen prong 3; (2) failed to consider the treating

neurosurgeon’s opinion as evidence in his Althen prong 3 analysis; (3) failed to consider

Petitioner’s elimination of alternative causes in assessing whether she satisfied her burden;

and (4) used an elevated standard of proof when assessing epidemiological evidence. See

ECF 109 at 6-7. The Court addresses each contention in turn.

I. Alleged Conflation of Althen Prongs 1 and 3

Petitioner contends that the Special Master elevated her burden of proof by

conducting an in-depth analysis of Petitioner’s medical theory of causation under his prong

3 analysis, thus conflating the requirements for Althen prongs 1 and 3. Id. at 22-24. She

maintains that the Special Master “erroneously created his own 2-part test” and effectively

required her “to demonstrate a precise biological mechanism of how GBS can occur in 1

day post vaccination.” Id. at 22, 24. Specifically, Petitioner takes issue with the following

statement by the Special Master:

Discussion of [prong 3] can be broken down into two distinct

topics: First, whether Dr. Steinman has provided an

immunologic explanation as to how an injury due to molecular

mimicry can occur within 24 hours; and second, whether

available epidemiology bolsters Dr. Steinman’s view or

otherwise persuasively establishes an increased risk of post-

vaccination GBS inclusive of the first day post-vaccination.

ECF 107 at 9; see ECF 109 at 22 (citing same).

The Court discerns no error in the Special Master’s analysis. First, the Court does

not read the Special Master’s decision to create an improper two-part test or require

Petitioner to demonstrate the precise biological mechanism by which a flu vaccine can

cause GBS in one day, as alleged by Petitioner. ECF 109 at 22. By indicating that

discussion of prong 3 would proceed in two parts, the Special Master merely signposted

the discussion and previewed the nature of the prong 3 evidence before him. At no point

did the Special Master state that, to succeed on prong 3, Petitioner was required to both:

(1) provide an immunologic explanation as to how an injury due to molecular mimicry can

7

occur within 24 hours; and (2) provide epidemiological proof. Indeed, the Special Master’s

language suggests the opposite. By acknowledging that epidemiological evidence might

either “bolster[] Dr. Steinman’s view or otherwise persuasively establish[] an increased

risk” on Day 1, the Special Master indicated that there was no requirement for Dr. Steinman

to provide an immunologic explanation and that epidemiological evidence might be used

to support prong 3 in lieu of Dr. Steinman’s expert opinion. See ECF 107 at 9 (emphasis

added). At no point did the Special Master rule out the use of other evidence or fault

Petitioner for failing to provide proof of specific biological mechanisms.

Second, the Special Master properly recognized that, to satisfy prong 3, “[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-in-fact.’” Id. at 8 (quoting de Bazan, 539 F.3d at

1352 (emphasis added)). “As de Bazan indicates, the ‘etiology’ of the disorder determines

the appropriate temporal relationship.” Veryzer v. Sec’y of Health & Hum. Servs., 100 Fed.

Cl. 344, 356 (2011), aff’d per curiam, 475 App’x 765 (Fed. Cir. 2012). Accordingly, the

Special Master correctly noted that “[t]he explanation for what is a medically acceptable

timeframe must coincide with the theory of how the relevant vaccine can cause an injury

(Althen prong one’s requirement).” ECF 107 at 8 (citing de Bazan, 539 F.3d at 1352). The

Special Master then went on to evaluate whether Petitioner’s one-day onset of symptoms

was compatible with Dr. Steinman’s theory of molecular mimicry. See id. at 9-18.

In conducting this portion of the prong 3 analysis, the Special Master thoroughly

evaluated whether Dr. Steinman persuasively explained how an injury due to molecular

mimicry can occur within 24 hours. See id. He weighed Dr. Steinman’s assessment of the

appropriate timing against Dr. Whitton’s competing views and concluded that “Dr.

Steinman is not persuasive in contending … that the immune response underlying his

theory can develop as quickly as he opines.” Id. at 10. Specifically, he found that “although

Dr. Steinman has demonstrated that a secondary or recall response does develop more

quickly than a primary immune response, the concept of a recall response does not explain

how molecular mimicry can occur within 24 hours.” ECF 107 at 12. After considering

concurrent immune processes proposed by Dr. Steinman, the Special Master further found

that “Dr. Steinman has not come forward with a preponderantly supported explanation of

how petitioner’s flu vaccine could have produced an autoantibody response leading to a

loss of immune self-tolerance and subsequent development of GBS within 24 hours of

vaccination.” Id. at 18. Ultimately, “[a]fter weighing the competing expert opinions,” the

Special Master found that “[R]espondent is persuasive in contending that it is biologically

implausible for GBS to develop in such a short period of time.” ECF 107 at 26. Thus, the

Special Master properly evaluated whether the temporal association Petitioner proposed

under the third Althen prong “relate[d] to the pathology of the specific medical theory

alleged to have caused the injury.” Veryzer, 100 Fed. Cl. at 356. He did not commit an

error of law.

8

II. The Treating Neurosurgeon’s Medical Opinion

Although Petitioner concedes that the Special Master considered the treating

physician’s opinion when discussing Althen prong 2, she argues that the Special Master

committed legal error by failing to also consider such evidence as part of his Althen prong

3 analysis. ECF 109 at 19-22. This argument fails.

To be sure, in Capizzano v. Secretary of Health & Human Services, the Federal

Circuit held that a special master committed legal error by failing to consider the opinions

of treating physicians. 440 F.3d 1317, 1326 (Fed. Cir. 2006). Specifically, having found

that the first and third prongs of the Althen test were satisfied, the Federal Circuit held that,

“[a]s far as the second prong is concerned, in our view, the chief special master erred in

not considering the opinions of the treating physicians who concluded that the vaccine was

the cause of [petitioner]’s injury.” Id. The Federal Circuit further explained:

The fact that these physicians’ diagnoses may have relied in

part on the temporal proximity of Ms. Capizzano’s injuries to

the administration of the vaccine is not disqualifying. We see

no reason why evidence used to satisfy one of the Althen III

prongs cannot overlap to satisfy another prong. In other words,

if close temporal proximity, combined with the finding that

hepatitis B vaccine can cause RA, demonstrates that it is

logical to conclude that the vaccine was the cause of the RA

(the effect), then medical opinions to this effect are quite

probative. Moreover, Althen III explained that 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.

Id. (internal citations and quotation marks omitted) (alteration in original).

Although Capizzano discusses the probative value of treating physicians’ opinions

specifically in the context of an Althen prong 2 analysis, several judges on this Court have

extended Capizzano’s logic regarding the heightened relevance of such evidence to Althen

prong 3. See, e.g., Campbell v. Sec’y of Health & Hum. Servs., 90 Fed. Cl. 369, 386-87

(2009) (Lettow, J.) (noting that statements made by treating physicians should be afforded

more than “some consideration” in addressing Althen prong 3); Contreras v. Sec’y of

Health & Hum. Servs., 107 Fed. Cl. 280, 299 (2012) (Bush, J.) (requiring that treating

physician opinions be given “significant weight” and observing that “it is difficult to

conceive of a treating physician who would conclude that a vaccine caused the petitioner’s

illness without also concluding that the onset of the illness was within a medically-

acceptable time frame”); Mosley v. Sec’y of Health & Hum. Servs., 119 Fed. Cl. 734, 742-

44 (2015) (Kaplan, J.) (finding that “the special master’s failure to even discuss [treating

physicians’] opinions in her analysis of prong three constituted legal error”).

9

The undersigned need not decide whether to follow Campbell, Contreras, and

Mosley in the present case because: (1) this case is distinguishable; and (2) any error in this

regard was harmless. First, unlike in the aforementioned cases, the treating physician’s

causal opinion included a caveat that calls into question whether she actually offered an

opinion relevant to Althen prong 3. Specifically, Dr. Rathmann wrote, “I believe that my

letter was correct and that the flu vaccination is more likely than not the cause of Ms.

Chevenok’s [sic] GBS; however, I would defer to a neurologist or immunologist on how

biologically this can occur.” ECF 53-1.

As discussed, prong 3 “requires preponderant proof that the onset of symptoms

occurred within a timeframe for which, given the medical understanding of the disorder’s

etiology, it is medically acceptable to infer causation-in-fact.” de Bazan, 539 F.3d at 1352

(emphasis added). Because Dr. Rathmann defers to others on “how biologically this can

occur,” the Court fails to see how she offered any real opinion as to whether Petitioner’s

GBS began in a “medically acceptable” timeframe under the medical theory alleged to have

caused Petitioner’s injury. See Veryzer, 100 Fed. Cl. at 356 (noting that “the temporal

association must relate to the pathology of the specific medical theory alleged to have

caused the injury”). The Court cannot fault the Special Master for failing to afford

significant weight to the treating physician’s medical opinion in his prong 3 analysis when

that opinion does not appear to speak to the relevant prong 3 question—whether the onset

of Petitioner’s GBS began in a timeframe consistent with the medical understanding of her

GBS’s etiology. de Bazan, 539 F.3d at 1352; see also Cedillo v. Sec’y of Health & Hum.

Servs., 617 F.3d 1328, 1348 (2010) (finding no error in special master’s failure to assign

significant probative weight where “none of the treating physicians concluded” that the

vaccine caused a petitioner’s injury).

Second, even if the Special Master had a duty to explicitly consider Dr. Rathmann’s

medical opinion in his evaluation of Althen prong 3, any failure to do so was harmless

error. See Hines, 940 F.2d 1526 (finding special master’s consideration of potentially

improper evidence was harmless error where “the special master’s decision was based on

a number of factors” and petitioner had not shown that reliance on the error “was likely

critical to the result”). This Court has previously found harmless error in some

circumstances where a special master may have impermissibly heightened a petitioner’s

burden of proof. See, e.g., Caves v. Sec’y of Health & Hum. Servs., 100 Fed. Cl. 119, 145

(2011) (concluding that, to the extent the special master heightened petitioner’s burden of

proof on Althen prong 1, any resulting errors were harmless as petitioner failed to meet her

burden of proof on prong 2); Tebcherani ex rel. Tebcherani v. Sec’y of Health & Hum.

Servs., 55 Fed. Cl. 460, 476 (2003) (holding that the Court was “constrained to find …

errors to be harmless in this case, because neither the Special Master’s inappropriate

reference of an alleged viral illness nor the improper assignment of the burden of proof

impacted the ultimate decision”).

Such is the case here. Petitioner concedes that the Special Master explicitly

addressed Dr. Rathmann’s medical opinion in his analysis of Althen prong 2, demonstrating

10

that he considered it as part of his overall causation-in-fact analysis. ECF 107 at 7-8.

Further, as noted above, Dr. Rathmann’s opinion was limited in that she expressly deferred

to others on etiology, which minimized the value of her opinion to the extent it supported

an appropriate temporal relationship under the medical theory alleged to have caused

Petitioner’s injury. And finally, to support her opinion that “the onset of GBS may occur

within 2 days post vaccination,” Dr. Rathmann relied on two medical studies that the

Special Master discussed at length in his analysis of prong 3. See ECF 53-1 at 1 (citing the

Salmon and Parks studies). In his description of Dr. Rathmann’s medical opinions, the

Special Master noted that Dr. Rathmann cited the Salmon and Park epidemiological studies

and explained that these studies were discussed in greater detail by the experts. ECF 107

at 6. He then went on to discuss those experts’ views. Id. at 21-23. As such, nothing in Dr.

Rathmann’s letters provided any additional reasoning for the Special Master to address.

Because Petitioner has not shown that the Special Master’s failure to explicitly consider

Dr. Rathmann’s testimony under prong 3 “was likely critical to the result,” Hines, 940 F.2d

at 1526, or “impacted the ultimate decision,” Tebcherani, 55 Fed. Cl. at 476, the Court

deems any such potential error harmless. Therefore, Petitioner’s argument fails.

III. Petitioner’s Elimination of Alternative Causes

Next, Petitioner alleges the Special Master’s assessment of Petitioner’s prima facie

case failed to consider evidence that Petitioner eliminated alternative infectious causes.

ECF 109 at 24-25. This challenge lacks merit.

Though a petitioner is not required to eliminate alternative causes to establish a

prima facie case, she “is certainly permitted to use evidence eliminating other potential

causes to help carry the burden on causation and may find it necessary to do so when the

other evidence on causation is insufficient to make out a prima facie case.” Walther v. Sec’y

of Health & Hum. Servs., 485 F.3d 1146, 1151 (Fed. Cir. 2007). “In such instances, clearly

the special master must evaluate what evidence a claimant presents as part of determining

whether the claimant makes a prima facie case.” Id. That said, “[a]lthough probative,

neither a mere showing of a proximate temporal relationship between vaccination and

injury, nor a simplistic elimination of other potential causes of the injury suffices, without

more, to meet the burden of showing actual causation.” Althen, 418 F.3d at 1278.

Here, the Special Master expressly acknowledged that “[n]o other cause of

[Petitioner]’s GBS has been asserted.” ECF 107 at 5. He also noted that “the elimination

of alternative causes” played a role in Dr. Rathmann’s causal opinion. Id. at 7-8. The

Special Master then concluded that, under Althen, “these considerations standing alone do

not carry petitioner’s burden of proof.” Id. at 8. The Special Master’s language makes clear

that he did consider evidence that Petitioner ruled out possible alternative causes; he just

did not give it the controlling weight Petitioner wishes he did. See ECF 109 at 24 (arguing

the Special Master “did not consider the weight of absence of alternative causes”)

(emphasis added). In this regard, Petitioner appears to invite this Court to second guess the

11

Special Master’s evaluation of the evidence, which this Court cannot do. See Porter, 663

F.3d at 1249.

IV. Alleged Elevation of Petitioner’s Burden of Proof

Petitioner argues that, when assessing the epidemiological evidence, the Special

Master utilized an elevated standard of proof, effectively requiring her to prove her case

with scientific certainty rather than preponderant evidence. ECF 109 at 10-19. Under this

umbrella, she alleges four specific errors on the part of the Special Master. For the reasons

that follow, the Court concludes that the Special Master’s disagreement with Petitioner’s

interpretation of epidemiology does not mean he elevated her burden to scientific certainty.

A. Epidemiological Evidence Requirement

First, Petitioner maintains that the Special Master applied a higher evidentiary

standard than Althen permits, requiring her to provide epidemiological evidence explicitly

demonstrating statistically significant results for Day 1 in particular. See ECF 109 at 15,

16, 19. She argues that her epidemiological studies presented statistically significant

findings for a risk period of 1-42 days, and the Special Master’s failure to credit those

studies impermissibly elevated her burden of proof. See ECF 109 at 10-19.

It is well settled that a petitioner need not present evidence of epidemiologic studies

to prove their prima facie case. Capizzano, 440 F.3d at 1325. That does not mean, however,

that special masters may not assess the reliability or probative value of any evidence a

petitioner chooses to present. See Moberly ex rel. Moberly v. Sec’y of Health & Hum.

Servs., 592 F.3d at 1325 (“But to say that proof in the form of epidemiological studies or

well-established medical experience is not mandatory does not mean that the special

masters in Vaccine Act cases are precluded from inquiring into the reliability of

testimony….”); see also Knudsen by Knudsen v. Sec’y of Health & Hum. Servs., 35 F.3d

543, 548 (Fed. Cir. 1994) (holding proof of actual causation “must be supported by a sound

and reliable medical or scientific explanation”). Indeed, special masters are entitled to

“demand[] some degree of acceptable scientific support.” Hodges v. Sec’y of Health &

Hum. Servs., 9 F.3d 958, 962 (Fed. Cir. 1993). Accordingly, “[a] special master may …

properly consider the weakness of medical literature support when evaluating the overall

reliability of scientific evidence.” Gamboa-Avila v. Sec’y of Health & Hum. Servs., 166 F.

4th 1318, 1322 (Fed. Cir. 2026) (citing Moberly, 592 F.3d at 1324).

That is exactly what the Special Master did here. He started by expressly articulating

and applying the preponderant evidence standard to the third Althen prong. See ECF 107

at 8, 18 (explaining a petitioner must offer preponderant proof of medically-acceptable

onset and that Dr. Steinman had not come forward with a preponderantly supported

explanation). Then, he explicitly wrote that he was not requiring epidemiological evidence.

Id. at 18 (“Of course, the Federal Circuit has previously stressed that a petitioner is not

obligated to prove a case with epidemiology.”). He went on to assess the reliability and

persuasiveness of both Dr. Steinman’s theories and the epidemiological evidence proffered

by Petitioner.

12

To be sure, the Special Master relied on the fact that none of the evidence submitted

by Petitioner established that Day 1, in particular, included any excess risk of GBS. See,

e.g., id. at 22. However, he also engaged in a robust analysis to determine whether the

evidence Petitioner presented had “some indicia of reliability.” Moberly, 592 F.3d at 1324.

With respect to Dr. Steinman’s theories, he weighed them against Dr. Whitton’s competing

opinions and noted specific deficiencies that rendered Dr. Steinman’s view unpersuasive

in his view. For example, the Special Master found that “although Dr. Steinman has

demonstrated that a secondary or recall response does develop more quickly than a primary

immune response, the concept of a recall response does not explain how molecular mimicry

can occur within 24 hours.” ECF 107 at 12. He likewise found that “[n]one of the evidence

or concepts presented by Dr. Steinman overcome the fundamental understanding that even

a recall response takes time to develop meaningful levels of antibodies.” Id.

With respect to Petitioner’s epidemiological evidence purporting to show an

increased risk of GBS within 1-42 days of vaccination, the Special Master carefully

considered weaknesses in the studies. For example, he credited Dr. Whitton’s testimony

that the Polakowski study had significant limitations, namely that: (1) the authors noted

they were unable to fully account for preceding infections;8 and (2) the study only resulted

in statistically significant findings when the broadest diagnostic criteria were used. ECF

107 at 22. He also agreed with Dr. Whitton that it is difficult to draw any conclusions from

the Park study, which examined the demographic characteristics of GBS patients who

submitted a claim for compensation under South Korea’s equivalent of the Vaccine

Program. Id. at 23. Specifically, the Special Master identified the following concerns: (1)

the study’s representation of “a highly selective group;” (2) the lack of information

concerning “what criteria the compensating authority uses to adjudge eligibility;” and (3)

the fact that the overall distribution curve observed in Park differed from those observed

in Schonberger, Salmon, and Polakowski, “strongly suggesting that the parameters of the

compensating scheme may have contributed to the distribution.” Id. at 23. Regarding

Schonberger, the Special Master noted that the study authors included an “explicit

indication” that, “despite expressing the period of elevated risk simply as five weeks post-

vaccination, they did believe that a relevant latency period was implicated even though

they did not explore it in detail.” Id. at 21. The Special Master’s recognition of these and

other weaknesses does not mean he directly or implicitly required epidemiological proof

of elevated risk on Day 1 or applied a standard inconsistent with Althen. See Gamboa-

Avila, 166 F. 4th at 1322. Instead, his conclusion simply reflects his assessment of the

record presented.

8

In her Motion for Review, Petitioner seemingly disputes this limitation. She contends that “Dr. Polakowski

… explicitly indicated that she excluded cases with preceding illness in her calculation of the statistically

significant increased risk of GBS.” ECF 109 at 16. Petitioner does not address that Dr. Polakowski expressly

qualified her study by acknowledging that her “ability to account for preceding respiratory/gastrointestinal

illness was limited.” ECF 68-4 at 1; see also id. at 9 (“Limitations of this study included the inability to

fully adjust for some potential confounders, including … preceding infections within the 6 weeks prior to

GBS onset.”).

13

B. Finding of Correlation

Next, Petitioner criticizes the Special Master for finding that epidemiological

studies demonstrate correlation, not causation, in contravention of the Vaccine Act’s

preponderant standard. ECF 109 at 18. Implicit in Petitioner’s criticism is a contention that

the Special Master erred by weighing her epidemiologic evidence against an improper

standard. Respondent argues that the Special Master merely recognized a truism, and that

this fact did not stop the Special Master from analyzing the epidemiology before him, as

he was required to do. ECF 112 at 18 n.5.

The Court agrees with Respondent. Here, the Special Master agreed with Dr.

Whitton’s suggestion that “epidemiologic data is limited to demonstrating correlation,

rather than causation.” ECF 107 at 20. In assessing the Salmon and Polakowski studies, he

later reiterated that “epidemiology is limited to demonstrating correlation.” Id. at 22.

Petitioner concedes that “this might be true in the scientific community that evaluates

findings based on statistical significance,” but argues that “in the Vaccine Court,

epidemiological evidence that finds a statistically significant association between a vaccine

and an illness is strongly indicative of causation.” ECF 109 at 18.

Petitioner correctly notes that epidemiological evidence may be used to satisfy a

petitioner’s burden. See, e.g., Knudsen, 35 F.3d at 549 (“[C]ausation can be found in

vaccine cases based on epidemiological evidence….”); Grant v. Sec’y of Health & Hum.

Servs., 956 F.2d 1144, 1149 (Fed. Cir. 1992) (“[E]pidemiological studies are probative

medical evidence relevant to causation.”). That does not mean, however, that special

masters must overlook the nature and limitations of such evidence. “[E]pidemiological

studies are designed to reveal statistical trends….” Moberly, 592 F.3d at 1324. They show

“a statistically-significant correlation between a given vaccine and a particular injury….”

Langland v. Sec’y of Health & Hum. Servs., 109 Fed. Cl. 421, 441 (2013). By

acknowledging that epidemiological evidence “finds a statistically significant

association,” Petitioner seemingly recognizes this reality. ECF 109 at 18 (emphasis added).

The Special Master’s recognition of this truism is not error.

Further, the fact the Special Master recognized this truism did not stop him from

analyzing whether “available epidemiology bolsters Dr. Steinman’s view or otherwise

persuasively establishes an increased risk of post-vaccination GBS inclusive of the first

day post-vaccination.” ECF 107 at 9. In other words, he looked to see if Petitioner’s

epidemiological studies warranted a causal inference. Had he actually believed that

Petitioner’s epidemiological studies were not relevant to causation, he would not have

devoted six full pages to reviewing their findings and analyzing their weaknesses. See id.

at 18-23. Under these circumstances, the Court cannot say that his recognition of what

epidemiological data factually shows elevated Petitioner’s burden of proof.

C. Consideration of Circumstantial Evidence

Petitioner also challenges the Special Master’s treatment of circumstantial evidence.

The use of circumstantial evidence is “envisioned by the preponderance standard” and

14

consistent with the “system created by Congress, in which close calls regarding causation

are resolved in favor of injured claimants.” Althen, 418 F.3d. at 1280. Improperly rejecting

circumstantial evidence thus impermissibly raises a claimant’s burden of proof. See

Capizzano, 440 F.3d at 1325-26. Seemingly recognizing this fact, the Special Master

explicitly acknowledged that “[a] petitioner may rely upon circumstantial evidence.” ECF

107 at 3.

Despite this acknowledgment, Petitioner alleges that the Special Master failed to

consider circumstantial evidence under Althen prong 3. ECF 109 at 13, 17-18. Specifically,

Petitioner maintains that the Special Master failed to consider as circumstantial evidence

the 11 cases of GBS that occurred on Day 1 in the Schonberger study and the 26 cases of

GBS that occurred within two days in the Park study. Id. at 13, 17. Unsatisfied with the

Special Master’s conclusions regarding the Schonberger and Park studies, she criticizes the

Special Master for not independently considering the cases underlying those studies as

standalone evidence. See id. at 13, 17-18.

This argument lacks merit. First, Petitioner effectively demands that this Court

apply a requirement for a special master to analyze underlying data as freestanding

evidence after evaluating the medical literature a petitioner presents. This Court is unaware

of any such requirement. Second, a special master is presumed to have considered all

proffered evidence, unless he indicates otherwise. Snyder v. Sec’y of Health & Hum. Servs.,

88 Fed. Cl. 706, 728 (2009); Moriarty by Moriarty v. Sec’y of Health & Hum. Servs., 844

F.3d 1322, 1328 (Fed. Cir. 2016). He made no such indication here. Indeed, review of the

Special Master’s Decision reflects that he wholly credited the existence of the allegedly

ignored cases as part of his analyses of the Schonberger and Park studies. With respect to

the Schonberger study, which he acknowledged “indicate[s] that incidence of GBS were

[sic] elevated relative to the first full week post-vaccination,” the Special Master

specifically noted that Figure 5 reflects “that approximately 11 cases of GBS occurred on

days 0-1, with day 0 being the day of vaccination.”9 ECF 107 at 19; see id. at 20

(acknowledging “the fact that some cases of GBS occurred on the first day post-

vaccination”). The Special Master then provided detailed reasons for declining to afford

the Schonberger study (and by implication, its underlying cases) significant weight. For

example, after reviewing the study’s data and conclusions, he determined that “it is not

clear that Schonberger … demonstrates any elevated risk of GBS on days 0-1 post-

vaccination,” especially as the authors did not draw this conclusion and “nothing in the

study details the relative risk by day or specifically concludes that the data depicted in

Figure 5 (11 cases of GBS on days 0-1) represented an increased risk in itself.” Id. at 20.

He further rejected Dr. Steinman’s invitation to juxtapose two separate figures in

Schonberger to reach such a conclusion when “these figures are not directly comparable”

9

Notably, the Schonberger study itself does not explicitly report 11 cases on Day 1. Instead, the Special

Master credited Dr. Steinman’s interpretation of Figure 5 as showing 11 cases of GBS occurring on Days

0-1 because the bar rises to just below the 12-case mark. See ECF 107 at 19 n. 11.

15

and “[t]he examined populations are not the same.” Id. And finally, he observed that “the

fact that some cases of GBS occurred on the first day post-vaccination does not invariably

lead to the conclusion that a causal relationship exists.” Id. These statements indicate that,

contrary to Petitioner’s assertion, the Special Master did consider the 11 cases that occurred

on Day 1 in Schonberger; he just declined to afford them the weight desired by Petitioner.10

Regarding the Park study, the Special Master likewise acknowledged that, of the 48

cases examined in the study, “more than half developed symptoms within 2 days.” ECF

107 at 23. He then explained that the Park study—and again, by implication, the underlying

cases—provide weak evidence of a medically acceptable timeframe due to the context of

the study, which examined the demographic characteristics of GBS patients who submitted

a claim for compensation under South Korea’s equivalent of the Vaccine Program. Id. For

instance, he observed that “the very high number of cases occurring within two days of

vaccination is inconsistent with the overall distribution curve observed in [Petitioner’s

other studies], strongly suggesting that the parameters of the compensation scheme may

have contributed to the distribution.” Id. He also noted that the study was based on a “highly

selective group” and that the study does not provide information on what criteria the

compensating authority uses to adjudge eligibility. Id. This thorough analysis shows that

the Special Master did not engage in the “complete dismissal of the circumstantial evidence

demonstrating 26 cases of GBS occurring within 48 hours,” as Petitioner alleges. ECF 109

10

Petitioner appears to raise two subsidiary arguments related to the Special Master’s perceived dismissal

of the Day 1 Schonberger cases. First, she objects to an “implausible inference from the Langmuir study …

about lognormal curve to dismiss those 11 cases.” ECF 109 at 13. Next, she argues the Special Master

“drew an implausible inference by relying on experimental studies that were not included in the record of

the case.” Id. at 13-14. The Court finds neither argument persuasive. Regarding the Langmuir study, the

Court agrees with Respondent that it is unclear what error Petitioner assigns to the Special Master’s

interpretation of Langmuir. See ECF 112 at 17-18. The Court reads the Special Master’s discussion of

Langmuir as limited to a summary of its findings. See ECF 107 at 20-21. And regarding the Special Master’s

reference to experimental studies, the Court finds that Petitioner mischaracterizes the Special Master’s

actions. The Special Master did not consider studies outside the record, as alleged by Petitioner. Instead, he

merely acknowledged that the Schonberger study referenced studies outside the record, and he considered

the fact that the Schonberger authors detected a similar latency period to that observed in those studies.

There is no indication the Special Master reviewed the unfiled studies himself. Nor did he draw any

conclusion beyond that stated in Schonberger—that a latency period exists between vaccination and onset.

See id. at 21. Under such circumstances, the Court cannot say that the Special Master improperly relied on

a study not present in the record. In any case, even if the Special Master had improperly considered studies

outside the record, such reliance did not amount to reversible error as “the special master’s decision was

based on a number of factors and [Petitioner] has not shown that reliance on the judicially noticed

[information] was likely critical to the result.” Hines, 940 F.2d at 1526; see also Doe v. Sec’y of Health &

Hum. Servs., 601 F.3d 1349, 1356 n.2 (Fed. Cir. 2010) (holding that the special master taking judicial notice

of a table of brain weights “was harmless,” as “[t]his table was not the only fact the special master relied

on, or even the most important one, in declining to credit Dr. Shane’s theory”).

16

at 18. Instead, the Special Master simply found that the mere existence of the cases cited

in the Park study was insufficient to meet Petitioner’s burden.

Overall, the Special Master’s analysis reflects that he carefully considered the

medical literature Petitioner presented—which specifically addressed the allegedly ignored

cases—and found they provide weak evidence of a medically-acceptable timeframe.

Because the Special Master thoroughly reviewed the Schonberger and Park studies’ data

and conclusions, see ECF 107 at 19-21, 23, Petitioner’s argument that the Special Master

improperly rejected circumstantial evidence fails.

D. Reliance on the Black Study

And finally, Petitioner maintains that the Special Master impermissibly raised her

burden of proof by relying on Dr. Whitton’s purportedly flawed interpretation of the Black

study to draw an implausible inference that the cases of GBS that occurred on Day 1 in the

Polakowski and Salmon studies occurred as a result of chance. See ECF 109 at 16-17. The

Black study is a piece of medical literature that “identified background rates of selected

medical events.”11 ECF 43-27 at 1. Specifically, Petitioner takes issue with the Special

Master’s crediting of Dr. Whitton’s testimony, based on the Black study, that five cases of

GBS are expected each day as coincidental background cases. ECF 109 at 16-17.

According to Petitioner, this calculation is flawed because it includes the number of GBS

cases occurring due to a preceding infection, which the Polakowski study explicitly

excluded. Id. at 16.

Conspicuously absent from Petitioner’s criticism is any corresponding statement

concerning the Salmon study. Instead, Petitioner isolates the Polakowski study and

specifies that the Special Master “made an implausible inference that cases that occurred

on day one (1) in Polakowski were coincidental or occurred by chance without any basis

for that from the actual study.” Id. at 17. Moreover, Petitioner overstates the significance

of the Polakowski study authors’ attempt to exclude cases with preceding respiratory or

gastrointestinal illness from their analysis; on multiple occasions, the study authors

acknowledged that one “limitation[] of th[eir] study included the inability to fully adjust

for some potential confounders, including … preceding infections within the 6 weeks prior

to GBS onset.” ECF 68-4 at 9; see also ECF 68-4 at 10 (reiterating that their “ability to

account for preceding illness was limited”); ECF 68-4 at 1 (same). Given these caveats,

Petitioner’s attack on the relevance of the Black study due to its failure to exclude GBS

cases preceded by infection is weak at best.

Accordingly, the Court finds the Special Master drew a plausible inference when he

inferred that “one or two cases of GBS occurring on any given day could be the result of

chance, greatly tempering the potential significance of [the Salmon and Polakowski]

findings.” ECF 107 at 23. In his purview as factfinder, the Special Master is empowered to

11

Steven Black et al., Importance of Background Rates of Disease in Assessment of Vaccine Safety During

Mass Immunisation with Pandemic H1N1 Influenza Vaccines, 374 LANCET 2115 (2009).

17

weigh competing evidence and determine whether one study (in this case, Black)

corroborates or undermines others (Salmon and Polakowski). See Porter, 663 F.3d at 1249

(“We do not reweigh the factual evidence, assess whether the special master correctly

evaluated the evidence, or examine the probative value of the evidence … these are all

matters within the purview of the fact finder.”); Moberly, 592 F.3d at 1326 (“Finders of

fact are entitled—indeed, expected—to make determinations as to the reliability of the

evidence presented to them….”).

Here, the Black study reported that, “if a cohort of 10 million individuals was

vaccinated in the UK, 21.5 cases of [GBS] … would be expected to occur within 6 weeks

of vaccination as coincident background cases.” ECF 43-27 at 1. The authors likewise

estimated that, if 100 million individuals were vaccinated during a pandemic H1N1 vaccine

campaign in the United States, “200 or more new cases of [GBS] would occur as

background coincident cases” in the 6-week follow-up period. Id. at 2. From these figures,

Dr. Whitton estimated that approximately five cases of GBS per day would occur simply

by chance across the 100 million people who receive flu vaccine each year in the United

States.12 ECF 92 at 124. It was not implausible for the Special Master to then infer that the

two Day-1 cases observed in Salmon and the one Day-1 case observed in Polakowski

“could be the result of chance” and thus did not represent “robust findings with respect to

day 1.” ECF 107 at 23. Accordingly, the Court discerns no error in the Special Master’s

reliance on the Black study or in his analysis.

CONCLUSION

In this case, the Special Master applied the correct legal standard and found that

Petitioner failed to prove causation by a preponderance of the evidence. That conclusion

has not been shown to be legally or factually erroneous. Petitioner’s Motion for Review

(ECF 109) is therefore DENIED and the Special Master’s Decision (ECF 107) is

SUSTAINED. The Clerk of the Court is DIRECTED to enter judgment accordingly.

IT IS SO ORDERED.

________________

PHILIP S. HADJI

Judge

12

Notably, Dr. Whitton’s calculation aligned with the Black study’s calculation of the number of expected

background coincident cases on Day 1. See ECF 43-27 at 6, Table 6. For GBS, the Black study predicted

that, per 10 million vaccinated people, .51 of them will develop GBS within one day. Id. Applying that

same logic to a population of 100 million vaccinated people (a tenfold increase), it would be reasonable to

see approximately five cases of GBS every day (10 * .51 = 5.1).

18