# Defenza v. Secretary of Health and Human Services

> United States Court of Federal Claims · June 16, 2026

URL: https://www.frixlaw.com/law-library/cases/11343897

## Case

- **Court:** United States Court of Federal Claims
- **Decided:** June 16, 2026
- **Precedential status:** Published
- **Opinion:** Opinion
- **Judges:** Philip S. Hadji
- **Cited by:** 0 later opinions in the Frix Law Library

## Citator (automated)

- No negative treatment found by the automated citator. That is not the same as a confirmation that the case is good law; read the citing cases.
- Full citator and citing cases: https://www.frixlaw.com/law-library/cases/11343897

## How later opinions describe it (automated extraction)

- noting that “the temporal association must relate to the pathology of the specific medical theory alleged to have caused the injury”
- holding proof of actual causation “must be supported by a sound and reliable medical or scientific explanation”
- 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”

## Opinion text

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

---

Source: Frix Law Library, https://www.frixlaw.com/law-library/cases/11343897. Public record. Not legal advice.