Beckwith v. Secretary of Health and Human Services

In the United States Court of Federal Claims

DEBORAH BECKWITH,

Petitioner,

v. No. 21-vv-1660

(Filed Under Seal: February 20, 2026

SECRETARY OF HEALTH AND HUMAN Reissued for Publication: March 9, 2026)1

SERVICES,

Respondent.

David John Carney, Green & Shafle LLC, Philadelphia, PA, for Petitioner. With him on the

briefs were Grant Douglas Godfrey, Mctlaw, Washington, DC, and Jennifer Anne Gore Maglio,

Maglio Christopher & Toale, P.A., Sarasota, FL.

Parisa Tabassian, Torts Branch, Civil Division, United States Department of Justice,

Washington, DC, for Respondent. With her on the briefs were Brett A. Shumate, Assistant

Attorney General, C. Salvatore D’Alessio, Director, Heather L. Pearlman, Deputy Director, and

Lara A. Englund, Assistant Director.

OPINION AND ORDER

Meriweather, Judge.

Petitioner, Ms. Deborah Beckwith (“Ms. Beckwith”), seeks review of Chief Special

Master Corcoran’s Entitlement Decision (“Decision”), denying her entitlement to compensation

pursuant to the National Childhood Vaccine Injury Act of 1986, 42 U.S.C. §§ 300aa-1–aa-34

(“Vaccine Act”). See Decision at 1, ECF No. 67. Ms. Beckwith filed a Petition under the

Vaccine Program of the Vaccine Act, alleging the influenza (“flu”) vaccine caused her to suffer

Guillain-Barré Syndrome (“GBS”)—a neurological disorder that can lead to numbness and

muscle paralysis. See Petition at 1, ECF No. 1. The applicable regulations establish a

presumption that the flu vaccine caused GBS if a petitioner proves that she developed GBS

between three and forty-two days after receiving the flu vaccine. 42 C.F.R. § 100.3(a)(XIV)(D).

Following a dispute about the number and timing of vaccines Ms. Beckwith received, the Chief

Special Master determined Ms. Beckwith received one dose of flu vaccine at approximately 2:20

AM on September 24, 2019 and that the onset of her GBS occurred less than three days after

vaccination. See Order Granting Second Motion for Reconsideration at 2–3, ECF No. 37.

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Pursuant to Vaccine Rule 18(b)(1)–(2), (d), this Opinion was initially filed under seal on

February 20, 2026, and the parties were afforded fourteen days to propose redactions. The

parties did not propose any redactions and, accordingly, this Opinion is reissued in its original

form for publication.

Accordingly, the Chief Special Master concluded he could not presume causation and Ms.

Beckwith had to prove causation-in-fact. The Chief Special Master determined that Ms.

Beckwith failed to prove causation-in-fact because she could not establish, by a preponderance

of the evidence, “that her GBS developed within a medically-acceptable timeframe after receipt

of the flu vaccine.” Decision at 21. He therefore denied her Petition. Id. at 2.

Ms. Beckwith now seeks review of the Chief Special Master’s Decision in this Court,

alleging he committed errors of law and made arbitrary and capricious factual findings. See

Pet’r’s Mot. for Review (“Mot.”), ECF No. 70; Pet’r’s Mem. of Law in Support of Pet’r’s Mot.

for Review (“Mem.”), ECF No. 70-1; see also 42 U.S.C. § 300aa-12(e)(1). Ms. Beckwith claims

the Chief Special Master: (1) erroneously limited the evidence she could use to prove that the

vaccine caused her GBS by treating the timeframe of onset that would support a presumption of

causation as a hard and fast rule with an overly narrow exception; (2) failed to properly consider

Ms. Beckwith’s medical theory of causation when evaluating whether she demonstrated a

proximate temporal relationship; (3) applied a heightened standard of proof to Ms. Beckwith’s

evidence; and (4) arbitrarily and capriciously evaluated Ms. Beckwith’s evidence. Mem. at 1.

Respondent, the Secretary of Health and Human Services (“the Secretary”), counters that Ms.

Beckwith has not shown the Chief Special Master erred. Resp’t’s Resp. to Mot. for Review

(“Resp.”) at 1, ECF No. 73.

Having reviewed the record, the parties’ legal filings,2 and the relevant law, the Court

DENIES Ms. Beckwith’s Motion for Review and SUSTAINS the Chief Special Master’s

Decision. The Chief Special Master did not commit an error of law, and Ms. Beckwith’s other

assertions amount to mere disagreement with the Chief Special Master’s well-reasoned factual

findings, which is not a basis for overturning his Decision. See Hines ex rel. Sevier v. Sec’y of

Health & Hum. Servs., 940 F.2d 1518, 1527 (Fed. Cir. 1991).

BACKGROUND

I. Statutory Framework

The Vaccine Act, enacted in 1986, created the National Vaccine Injury Compensation

Program, through which claimants can petition to receive compensation for vaccine-related

injuries or death. See generally 42 U.S.C. § 300aa-10(a). The Act identifies two ways for a

petitioner to establish causation and thus qualify for compensation. First, a petitioner may

establish that she, after receiving a designated vaccine, suffered an injury listed on the Vaccine

Injury Table within the requisite time-period—commonly called a “Table Injury,” see 42 C.F.R.

§ 100.3(a)—in which case causation is presumed. See 42 U.S.C. § 300aa-11(c)(1).

Alternatively, if a petitioner claims entitlement for an injury not listed in the Vaccine Injury

2

The following filings are relevant to this Opinion: Petition, ECF No. 1; Mot., ECF No.

70; Mem., ECF No. 70-1; Resp., ECF No. 73. Throughout, page citations to documents in the

record refer to the document’s original pagination, unless the page is designated with an asterisk

(e.g., *1), in which case the reference is to the pagination assigned by PACER/ECF.

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Table, i.e., an “Off-Table case,” the petitioner must instead prove that the vaccination was the

cause-in-fact (“actual causation” or “causation-in-fact”) of the vaccinee’s asserted injury. See id.

§ 300aa-11(c)(1)(C)(ii)(I), (II). To prove causation-in-fact for an Off-Table case, a petitioner

must by a preponderance of the evidence demonstrate: “(1) a medical theory causally connecting

the vaccination and the injury; (2) a logical sequence of cause and effect showing that the

vaccination was the reason for the injury; and (3) a showing of a proximate temporal relationship

between vaccination and injury.” Althen v. Sec’y of Health & Hum. Servs., 418 F.3d 1274, 1278

(Fed. Cir. 2005). Those three elements are commonly referred to as the “Althen prongs.” A

“failure to establish any one prong is dispositive.” Exum v. Sec’y of Health & Hum. Servs., 175

Fed. Cl. 681, 702 (2025).

II. Factual Background

The Chief Special Master summarized and evaluated Ms. Beckwith’s medical history

over the relevant time period, both parties’ expert reports, the medical literature submitted, and

the relevant legal standards. See generally Decision. The Chief Special Master reviewed all the

medical records, the medical literature, and the expert reports submitted in this case, but only

specifically discussed the records, literature, and reports relevant to his conclusion on the third

Althen prong in his Decision. Id. at 4, 20. This Opinion will briefly summarize the relevant

undisputed facts, the expert reports, and the Chief Special Master’s determinations.

A. Ms. Beckwith’s Medical History

Ms. Beckwith was admitted to the Emergency Department at a Department of Veterans’

Affairs Medical Center on September 23, 2019. Id. at 2 (citing Ex. 3 at 319, ECF No. 6-3). She

reported “abdominal pain that had persisted for 11 days” and that she was recovering from an

upper respiratory infection (“URI”). Id. A doctor diagnosed Ms. Beckwith with “[s]epsis

secondary to infection of the common bile duct.” Id. (citing Ex. 3 at 314, 322). At

approximately 2:20 AM on September 24, 2019, Ms. Beckwith received a flu vaccine and

experienced no immediate reactions to the vaccine. Id. at 2, 12 (citing Ex. 15 at 6, ECF No. 35-

1).

Later that day, a doctor referred Ms. Beckwith to a gastroenterologist due to concerns she

may be experiencing cholangitis stemming from a prior gallbladder removal. Id. at 2–3. The

gastroenterologist ordered an endoscopic retrograde cholangiopancreatography (“ERCP”). Id. at

3. Ms. Beckwith underwent the ERCP in the afternoon on September 25, 2019, and first

reported neurological symptoms that reflected GBS a few hours after the procedure, including

“numbness in both hands as well as numbness in both feet,” less than two days following her flu

vaccine. Id. (quoting Ex. 3 at 256). A doctor diagnosed Ms. Beckwith with GBS, Miller-Fisher

variant (“MFS”)—a “variant of Guillain-Barré syndrome characterized by areflexia, ataxia, and

ophthalmoplegia”—on September 30, 2019. Id. at 3 & n.4 (citation omitted).

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B. Procedural History

On August 4, 2021, Ms. Beckwith filed her Petition against the Secretary alleging the flu

vaccine caused her to suffer GBS. Petition at 1. Initially, Ms. Beckwith asserted that she

received three doses of the flu vaccine between September 23 and September 24, 2019, and

alleged she was entitled to compensation for a Table injury. Id. at 2. The Secretary contested

Ms. Beckwith’s factual record of vaccination and contended that even if Ms. Beckwith received

the earliest alleged flu vaccine, her GBS onset occurred too early for a Table injury claim, given

the Table’s GBS-onset requirement of three to forty-two days after vaccination. Resp’t’s Rep. at

7, ECF No. 18. The Chief Special Master ordered the parties to brief the factual issue of whether

Ms. Beckwith’s records substantiated any of her vaccinations. Order, ECF No. 27. The Chief

Special Master then dismissed Ms. Beckwith’s Petition for failing to prove she received the flu

vaccine on any of the dates alleged. See ECF No. 30.

Ms. Beckwith moved for reconsideration twice and only on her second motion was she

able to identify a previously unfiled document confirming one of her alleged vaccinations. See

ECF Nos. 31, 36. The Chief Special Master granted the second motion and determined “that in

the early house of [September 24, 2019] (2:20 a.m.), Ms. Beckwith did in fact receive a single

dose of the flu vaccine.” ECF No. 37 at 2. However, the Chief Special Master also determined

Ms. Beckwith could not pursue a Table injury claim because her GBS-onset occurred less than

three days after this vaccination and instead ordered Ms. Beckwith to file an expert report

substantiating her alternative off-Table claim. Id. at 2–3.

C. Expert Opinions and Medical Literature

1. Ms. Beckwith’s Experts

a. Dr. Joseph Jeret

Ms. Beckwith submitted expert reports from Dr. Joseph Jeret, a neurologist, and one of

those reports is relevant to the current dispute. See Decision at 4. Dr. Jeret opined that the onset

of Ms. Beckwith’s GBS occurred “approximately 36 hours” after her flu vaccination and “that an

onset of neurologic symptoms the following day . . . [is] medically acceptable for flu vaccine-

caused GBS.” Id. at 5 (citing Jeret Rep. at 10, ECF No. 42-1). The Chief Special Master found

Dr. Jeret’s medical opinion unpersuasive. Id. at 24–26.

The Chief Special Master reviewed Dr. Jeret’s citations to medical and scientific

literature but found them unconvincing or irrelevant to establishing a medically acceptable

temporal connection between the flu vaccine and GBS in Ms. Beckwith’s case. Id. at 4–6, 24–

26. One study “relied on data derived from South Korea’s vaccine adverse event compensation

program, identifying 48 cases (over a 12-year period) in which individuals were compensated for

GBS post-vaccination injuries.” Id. at 5 (citing Y. Park et al., Clinical Features of Post-

Vaccination Guillain-Barré Syndrome (GBS) in Korea, J. Korean Med. Sci. 2017 Jul.

32(7):1154–59, filed as Ex. 45, ECF No. 44-8) (“Park”). The study found GBS “occur[ed]

within two days in a bit more than half” of cases.” Id. (citing Park at 1156). The Special Master

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concluded the study “does not stand for the proposition that an onset of less than two days has

been found to be medically acceptable” because it relies on data from South Korea’s equivalent

of the Vaccine Program and “could reflect a policy decision.” Id. at 24.

Dr. Jeret also cited to “a retrospective study of passive surveillance data derived from the

Vaccine Safety Datalink” where “researchers observed evidence of [GBS] ‘[o]nset as early as 1

day after flu vaccination,’” but the Chief Special Master stated it “ma[de] no determination about

the relative risk temporally from vaccination.” Id. at 5 (citing Jeret Rep. at 10). A third paper

“relied on data from a pool of Medicare recipients,” some of whom “reported [GBS] onset within

a few days of [flu] vaccination.” Id. at 6 (citation omitted). But the Chief Special Master found

the paper “did not reach conclusions about more specific questions of temporal risk.” Id. A

fourth article focused specifically on instances of the MFS variant of GBS following several

vaccinations, including the flu vaccine. Id. But the Chief Special Master determined it did not

find an “increase in incidence of [MFS] after vaccination as compared to the general population”

and instead merely observed the variant within 2 weeks in 24% of instances. Id. (citation

omitted). Dr. Jeret contended “onset after 2 days is consistent with this review.” Id. (citing Jeret

Rep. at 10). However, the Chief Special Master found the study “does not stand for the

proposition that onset within a day or two of vaccination is as likely as within a week or more.”

Id. at 25.

The Chief Special Master concluded Dr. Jeret “repeatedly identifies literature relying on

passive surveillance reports of GBS beginning in a comparably-short timeframe” as Ms.

Beckwith’s GBS onset, but that the studies “do not opine as to the meaningfulness of these

occurrences, for purposes of causation” and reflect only “a temporal association between an

adverse event and vaccination.” Id. at 24 (citing Campbell v. Sec’y of Health & Hum. Servs., 97

Fed. Cl. 650, 668 (2011)). The Chief Special Master found the articles “do not provide any

reliable basis for concluding that the biologic process necessary” for the flu vaccine to cause

GBS “could occur in less than two days.” Id.

b. Dr. Omid Akbari

Dr. Omid Akbari, an academic immunologist, submitted two reports in support of Ms.

Beckwith’s theory of causation. Id. at 6. The Chief Special Master found neither report

persuasive. Id. at 6–9, 25–26. Regarding Dr. Akbari’s first report, the Chief Special Master

stated that while “prong one causation is not at issue in this case, a brief summary of Dr.

Akbari’s theory” was necessary, “since it bears on whether Petitioner’s GBS began in a

medically acceptable timeframe.” Id. at 7 (citing First Akbari Rep. at 7–17, ECF No. 43-1); see

also id. at 16–17 (citing de Bazan v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1352 (Fed.

Cir. 2008)) (noting the “medically acceptable timeframe must align with the theory of how the

relevant vaccine can cause an injury (Althen prong one’s requirement)”).

The Chief Special Master characterized Dr. Akbari’s theory as “sweeping” and “all-

encompassing.” Id. at 7. He summarized the theory as follows:

[A] vaccine (a) causes a local reaction, stimulating an immune complex called the

“inflammasome,” (b) encourages the production of cytokines as well as T “helper

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cells” that are integral to the process of production of antibodies by B cells, (c)

impacts the function of immune regulatory cells that suppress aberrant immune

responses, and (d) eventually prompts the creation of antibodies in response.

Id. (citing First Akbari Rep. at 7–8). Dr. Akbari also posited that vaccines activate a class of

immune cells known as “innate like lymphocytes (‘ILLs’) that act quickly, and are likely

involved []in the induction of demyelinating diseases such as GBS.” Id. (citing First Akbari Rep.

at 10). The Chief Special Master concluded that Dr. Akbari “applied an expansive definition” of

the “molecular mimicry . . . accepted as a likely mechanism for GBS,” because Dr. Akbari’s

definition included T helper cell reactions, one of which purportedly “encouraged” the

development of GBS. Id. (citing First Akbari Rep. at 5–9). The Chief Special Master further

stated that Dr. Akbari “claimed that molecular mimicry was accepted despite the difficulty in

ever showing an actual mimic.” Id.

The Chief Special Master was also unconvinced by Dr. Akbari’s citations to medical

literature to support his opinion that a vaccine-caused onset of GBS within two days of the flu

vaccine is medically acceptable. Some of these citations were to the same studies the Chief

Special Master found unpersuasive in Dr. Jeret’s medical opinion, including the Park study. Id.

at 7–8. Other citations included a study not specific to GBS that determined the flu vaccine was

“likely to encourage a faster immune response” and an article focused on the central nervous

system (“CNS”), which “established that T cells could quickly impact the nervous system” and

cause demyelination. Id. at 8. However, the Chief Special Master noted “GBS is not a CNS

disease, and so the speed with which [an immune cell] might be thought capable in some

instances of moving into, or out of, the CNS does not suggest GBS will occur as quickly as Dr.

Akbari posits.” Id.

In his second report, filed after the Secretary’s experts submitted reports, Dr. Akbari

maintained “ILLs were known to be fast-acting, could promote production of cytokines and T

helper cells, and likely played some role in encouraging ‘the development of demyelinating and

autoimmune disease,’ including acute forms of GBS.” Id. (citing Second Akbari Rep. at 28, ECF

No. 53-2). However, as the Chief Special Master noted, Dr. Akbari acknowledged the “need for

greater understanding of ILL function in the hyper-acute phase of inflammation such as

vaccination and adverse effects that may occur within hours or few days.” Id. (citing Second

Akbari Rep. at 28). That revealed that “the science on this subject is far less firm than [Dr.

Akbari] implied.” Id. Still, Dr. Akbari “deemed it likely the Petitioner ‘possessed a higher

number of ILLs,’ assuming ‘genetic or environmental factors’ relevant to her.” Id. at 9 (citing

Second Akbari Rep. at 29). But the Chief Special Master noted such unique genetic or

environmental factors were “not substantiated in this case.” Id. Dr. Akbari concluded it was

“plausible” for GBS onset to occur less than two days after vaccination. Id. (Second Akbari Rep.

at 30).

The Chief Special Master determined that Dr. Akbari’s theory “may be biologically

correct and/or supported by reliable independent evidence in many respects,” but does not

“implicat[e] vaccination as an ‘x factor’ leading to injury, and does not identify with enough

reliable specific evidence where and how this occurs.” Id. at 25. Further, while Dr. Akbari

“offered numerous literature citations, and provided an explanation about how different aspects

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of the immune response work (or are speculated to work in some faster contexts—such as with

ILLs), his opinion amounted to the contention that it was plausible that GBS could be triggered

in a shorter time than commonly understood.” Id. The Chief Special Master noted plausibility

“is not equivalent to evidence that GBS likely occurs in a day or two of vaccination” and that Dr.

Akbari’s cited literature “does not constitute a preponderant showing on the timeframe

question.” Id. Rather, he concluded it “remains more likely than not that it takes more than two

days for flu vaccine-caused GBS to produce autoantibodies sufficient to result in manifestation

of outward, clinically-observable symptoms.” Id.

2. The Secretary’s Experts

i. Dr. Peter Kang

Dr. Peter Kang, a neurologist, submitted an expert report on behalf of the Secretary. Id.

at 9. Dr. Kang “maintained that ‘no compelling evidence in the literature’ supported the

conclusion that the GBS variant experienced by Petitioner could clinically manifest in such a

short time frame ‘following an immunogenic exposure.’” Id. at 10 (citing Kang Rep. at 16, ECF

No. 50-1). Dr. Kang asserted—and provided literature supporting the conclusion—that the

immune response following the flu vaccine takes several days. Id. He argued Ms. Beckwith

displayed GBS symptoms too early “for the vaccine to have been responsible for th[e]

antibodies” that drove the development of her GBS. Id. The Chief Special Master concluded

Dr. Kang “relied on what is known about GBS and its autoantibody propagation” to determine it

was unlikely the flu vaccine caused Ms. Beckwith’s GBS. Id. at 26. Thus, the Chief Special

Master found the medical opinion persuasive. Id.

ii. Dr. William Hawse

Dr. William Hawse, an academic immunologist, was the Secretary’s second expert. Id. at

10. Dr. Hawse found Ms. Beckwith’s GBS onset occurred “within a day of vaccination” and

thought “it unlikely GBS could manifest in so short a timeframe.” Id. at 10 (citing Hawse Rep.

at 11, ECF No. 49-1). Dr. Hawse maintained ILLs “could be quickly stimulated by vaccination.

But the existing scientific and medical literature on the topic was too sparse to conclude either

that vaccines likely do stimulate these immune cells, or (and more importantly) that they lead to

GBS.” Id. at 10–11 (citing Hawse Rep. at 11). Moreover, he contended that while “there is

some inflammasome stimulation attributable to receipt of the flu vaccine,” the medical literature

does not support the contention that “this stimulation would be sufficiently aberrant to cause a

disease process leading to GBS.” Id. at 11 (citing Hawse Rep. at 4–5). On the contrary, certain

scientific evidence pointed to the flu vaccine suppressing “some innate responses that would be

otherwise pro-inflammatory.” Id. (citing Hawse Rep. at 5–6). Dr. Hawse also opined that Ms.

Beckwith’s URI and infection-associated sepsis were more reasonable potential causes of her

GBS. Id. at 10.

Like Dr. Kang’s medical opinion, the Chief Special Master found Dr. Hawse’s medical

opinion convincing and supported by immunological science. Id. at 26. The Chief Special

Master also noted the Secretary’s experts’ opinions were both “consistent with the Table

timeframe” for GBS onset following the flu vaccine. Id.

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D. The Chief Special Master’s Conclusions

After the parties filed expert reports, the Chief Special Master issued an Order to Show

Cause as to why the Petition should not be dismissed for failing to satisfy the third Althen prong,

which the parties briefed. See ECF Nos. 56, 60, 62. The Chief Special Master then issued his

Decision denying Ms. Beckwith’s Petition for failing to satisfy the third Althen prong on August

29, 2025. See generally Decision.

The Chief Special Master noted that Ms. Beckwith’s medical records “memorialize an

onset of neurologic symptoms following the September 25, 2019, ERCP procedure, which

included ‘ataxia, weakness, pain, areflexia, dysphagia, dysarthria, hypophonia, tremors and

sensory deficits in extremities.’” Id. at 4 (citing Ex. 5 at 14, ECF No. 6-5). He concluded both

parties accept Ms. Beckwith’s GBS onset occurred “less than three days” post-vaccination “and

the record preponderates in favor of an onset occurring sooner (35 to 40 hours post-

vaccination).” Id. at 21–22.

The Chief Special Master concluded that Ms. Beckwith “has not preponderantly

established that her GBS developed within a medically-acceptable timeframe after receipt of the

flu vaccine.” Id. at 21. He reasoned that “medical science suggests that it is unlikely, absent

factors specific to a given claimant, that vaccine-caused GBS will occur sooner than three days

post-vaccination.” Id. at 26. Rather, “in most cases GBS will more likely than not take a few

days to manifest clinically after an environmental trigger (whether infection or vaccination),

given the time it takes for the body to manufacture the pathogenic, cross-reactive antibodies.”

Id. The Chief Special Master acknowledged “Petitioner’s experts [] unquestionably vouched for

the medical acceptability of a one to two-day onset of GBS post-vaccination,” but stated he was

not bound by their insufficiently supported assertions and “found the counter-opinions of

[Respondent’s experts] far more persuasive.” Id. He determined Ms. Beckwith failed to prove

any “special factors,” such as “her personal health or other circumstances made a fast onset

likely” in her case. Id.; see also id. at 23 (“The[] facts do not suggest a faster aberrant immune

response leading to GBS was more likely in Petitioner’s case (no matter how plausible it might

be), or did occur.”).

Ms. Beckwith timely filed her Motion for Review on September 26, 2025. See Mot. The

Secretary filed his Response on October 24, 2025. See Resp.

STANDARD OF REVIEW

“Under the Vaccine Act, the Court of Federal Claims reviews the decision of the special

master to determine if it is arbitrary, capricious, an abuse of discretion, or otherwise not in

accordance with law.” de Bazan, 539 F.3d at 1350 (citing Althen, 418 F.3d at 1277); see also 42

U.S.C. § 300aa-12(e)(2). In Vaccine Act cases, this Court uses three distinct standards of

review—fact findings are reviewed under the “arbitrary and capricious” standard; legal

conclusions are reviewed under the “not in accordance with law” standard; and discretionary

rulings are reviewed under the “abuse of discretion” standard. Munn v. Sec’y of Health & Hum.

Servs., 970 F.2d 863, 870 n.10 (Fed. Cir. 1992) (cleaned up).

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This Court reviews de novo whether a special master did not act in accordance with the

law. See Althen, 418 F.3d at 1279. “‘Not in accordance with the law’ refers to the application of

the wrong legal standard.” Rodriguez v. Sec’y of Health & Hum. Servs., 632 F.3d 1381, 1384

(Fed. Cir. 2011) (citing Markovich v. Sec’y of Health & Hum. Servs., 477 F.3d 1353, 1356 (Fed.

Cir. 2007)). The Court owes “no deference to the . . . special master on questions of law.”

Broekelschen v. Sec’y of Health & Hum. Servs., 618 F.3d 1339, 1345 (Fed. Cir. 2010).

The standard of review for factual findings is “the most deferential possible.” Munn, 970

F.2d at 870. The U.S. Court of Appeals for the Federal Circuit has warned against “second

guess[ing] the Special Master[’]s fact-intensive conclusions,” particularly in those cases “in

which the medical evidence of causation is in dispute.” Hodges v. Sec’y of Health & Hum.

Servs., 9 F.3d 958, 961 (Fed. Cir. 1993) (describing the standard of review as “uniquely

deferential for what is essentially a judicial process”). The law is settled that this Court cannot

“substitute its judgment for that of the Special Master merely because it might have reached a

different conclusion.” Snyder v. Sec’y of Health & Hum. Servs., 88 Fed. Cl. 706, 718 (2009)

(cleaned up). Further, a “special master’s decision often times is based on the credibility of the

experts and the relative persuasiveness of their competing theories.” Broekelschen, 618 F.3d at

1347 (citing Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357, 1362 (Fed. Cir. 2000)).

These credibility findings “are virtually unchallengeable on appeal.” Lampe, 219 F.3d at 1362.

A special master also does not need to “discuss every item of evidence in the record”

when making a factual finding “so long as the decision makes clear that the special master fully

considered a party’s position and arguments on point.” Snyder v. Sec’y of Health & Hum. Servs.,

36 Fed. Cl. 461, 466 (1996), aff’d, 117 F.3d 545 (Fed. Cir. 1997) (citation omitted); see also

Hazlehurst v. Sec’y of Health & Hum. Servs., 604 F.3d 1343, 1352 (Fed. Cir. 2010) (noting the

Court should presume the special master has considered all the material in the record, regardless

of whether she mentions it all). This Court “does not reweigh the factual evidence, [] assess

whether the Special Master correctly evaluated the evidence[,] . . . [or] examine the probative

value of the evidence or the credibility of the witnesses.” Broekelschen, 618 F.3d at 1349

(citation omitted).

“If [a] 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, 940 F.2d at 1528. Accordingly, this Court should not deem a

special master’s fact conclusions arbitrary and capricious unless they are “so implausible that

[they] could not be ascribed to a difference in view.” Id. at 1527 (cleaned up). Indeed, if a

special master’s “conclusion is based on evidence in the record that is not wholly implausible,”

this Court must “uphold that finding as not being arbitrary or capricious.” Cedillo v. Sec’y of

Health & Hum. Servs., 617 F.3d 1328, 1338 (Fed. Cir. 2010).

DISCUSSION

Ms. Beckwith challenges the Chief Special Master’s conclusion that she failed to satisfy

the third Althen prong. Althen prong three requires a petitioner to establish a “proximate

temporal relationship between the vaccination and the injury.” Paluck v. Sec’y of Health &

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Hum. Servs., 786 F.3d 1373, 1383–84 (Fed. Cir. 2015); see also Althen, 418 F.3d at 1278. That

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 (discussing proof requirements governing claim

where special master concluded onset of symptoms occurred too soon to support inference of

causation-in-fact). Special masters must conduct a case-by-case analysis of the merits of the

petitioner’s claim based on the evidence presented in that case. Althen, 418 F.3d at 1281; see

also Lampe, 219 F.3d at 1366; Davis v. Sec’y of Health & Hum. Servs., No. 14-978V, 2022 WL

1654743, *26 (Fed. Cl. Apr. 27, 2022).

As noted above, Ms. Beckwith contends the Chief Special Master erred in four ways.

She claims that he: (1) erroneously converted the required onset timeframe for a GBS Table

injury into a hard and fast rule regarding the timing of GBS onset for an Off-Table claim; (2)

failed to properly consider Ms. Beckwith’s medical theory of causation when evaluating whether

she demonstrated a proximate temporal relationship between the flu vaccine and her

development of GBS; (3) applied a heightened standard of proof to Ms. Beckwith’s evidence;

and (4) arbitrarily and capriciously evaluated Ms. Beckwith’s evidence. Mem. at 1. The Court

has considered each of Ms. Beckwith’s claims and sustains the Chief Special Master’s Decision.

I. The Chief Special Master Did Not Require Ms. Beckwith’s Off-Table Claim to

Satisfy the Timing Requirements Governing GBS Onset in Vaccine Injury Table

Claims.

Ms. Beckwith asserts that the Chief Special Master committed an error of law because he

purportedly applied a hard and fast three-day GBS onset rule from the Vaccine Injury Table to

her Off-Table GBS claim. See Mem. at 5, 9. In Paluck, the Federal Circuit faulted a special

master for applying a “hard and fast deadline” of three weeks for the onset of symptoms

allegedly attributable to a vaccine. Paluck, 786 F.3d at 1383–84. The Court concluded that the

variety of disorders and the paucity of relevant scientific literature made it unreasonable for the

special master to require the petitioner to show that symptoms manifested within that strict three-

week deadline. Id. Ms. Beckwith contends that the Chief Special Master similarly erred by

unlawfully requiring her to “overcome the presumption” that GBS onset generally only occurs at

least three days after vaccination, as articulated in the Vaccine Injury Table. Mem. at 11–12.

The Chief Special Master allegedly limited “the type of evidence and argument” she could

submit to showing how “specific facts of [her] medical history or personal circumstances

support[ed] a faster onset.” Id. (cleaned up). Ms. Beckwith contends that she should have been

allowed to submit “a new, general medical theory explaining how the immune system may react

earlier in outlier cases.” Id. at 12.

First, the Chief Special Master did not require Ms. Beckwith to prove that her GBS onset

occurred at least three days after her flu vaccine, as required for a Table claim, to meet her

burden of proof in this Off-Table case. In his Decision, the Chief Special Master stated “the

medical science behind a Table claim—the raison d’etre for its existence—should not be

ignored” and “should still be taken into account to some degree when deciding claims that ‘fall

out’ of the Table.” Decision at 22. He explained that the Table “timeframe best captures the

most likely period in which flu vaccine-caused GBS would begin, based on the most persuasive

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and reliable science available when the terms of the Table claim were struck.” Id. at 23.

However, he was clear that “[p]etitioners alleging a non-Table, causation-in-fact flu vaccine-

GBS claim are of course not formally limited, in any ‘bright line’ sense, by the Table’s

timeframe element.” Id. at 22. He also acknowledged that a claimant theoretically could

establish temporal proximity even if their case presents “a shorter (or longer) onset timeframe

than what the Table allows for GBS.” Id. at 23. He then assessed whether Ms. Beckwith had

met her burden to show by a preponderance of the evidence that the onset of GBS less than three

days after vaccination was a medically acceptable means of establishing causation in her case.

Id. at 21–26. Thus, the Chief Special Master did not apply an improper “hard and fast”

timeframe like the ruling that Paluck overturned. See Paluck, 786 F.3d at 1383–84 (finding a

special master erred when he stated petitioners “must” show manifestation within a particular

timeframe to meet their burden of proof); see also Correira v. Sec’y of Health & Hum. Servs.,

179 Fed. Cl. 286, 298 (2025) (finding a special master erred when he “impose[d] an inflexible

‘up-to-eight weeks timeframe’” for when it is medically acceptable to infer the flu vaccine

caused GBS) (emphasis added).

Second, the Chief Special Master properly articulated the legal standard. He held that

where evidence establishing “what about the specific facts of [a petitioner’s] medical history or

personal circumstances suggests a faster onset due to vaccination could occur,” is lacking, “it is

reasonable to find the third Althen prong has not been satisfied.” Decision at 23. He concluded

Ms. Beckwith failed to prove any “special factors,” such as “her personal health or other

circumstances made a fast onset likely” in her case. Id. at 26. In doing so, he appropriately

evaluated whether Ms. Beckwith had established a medically acceptable timeframe from which

to infer causation “based on the circumstances of the particular case.” Knudsen v. Sec’y of

Health & Hum. Servs., 35 F.3d 543, 548 (Fed. Cir. 1994).

Finally, it was not legal error for the Chief Special Master to consider the Table

timeframe for GBS onset when assessing whether the record evidence supported an inference of

causation. Neither Althen nor this Court’s precedent requires special masters to ignore the

scientific findings on which the Table’s onset time parameters are based. The Chief Special

Master referenced the Table and evaluated the entirety of the evidence and medical opinions Ms.

Beckwith offered. See Decision at 2–14, 21–26.

This Court has repeatedly found similar applications of the third Althen prong to be

legally proper. For example, in Flowers, the Court upheld the Chief Special Master’s conclusion

that a claimant had failed to establish that the flu vaccine caused GBS where the onset occurred

less than three days after her vaccine. See Flowers v. Sec’y of Health & Hum. Servs., 173 Fed.

Cl. 613, 629 (2024). The Court cited the Chief Special Master’s observation that Flowers “ha[d]

not explained how or provided any evidence demonstrating that in this case, in an exception to

the generally accepted timeframe for the onset of symptoms, the flu vaccine caused her to

experience GBS symptoms less than three days after vaccination.” Id. Similarly, in Kindle, the

Court upheld the Chief Special Master’s recognition that it was inappropriate to infer causation

when the petitioner’s GBS onset occurred later than the longest timeframe previously accepted

by special masters “where Petitioner had failed to proffer preponderant evidence that such an

unusually lengthy post-vaccination onset . . . could still be deemed medically acceptable.”

Kindle v. Sec’y of Health & Hum. Servs., 177 Fed. Cl. 689, 715 (2025) (cleaned up). In Mager,

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the Court upheld a special master’s consideration of the Table as “additional support” for the

expert opinions regarding a medically acceptable timeframe for the onset of a seizure disorder.

Mager v. Sec’y of Health & Hum. Servs., 166 Fed. Cl. 414, 449 (2023), appeal dismissed, No.

2023-2382, 2023 WL 7318303 (Fed. Cir. Nov. 7, 2023). For the same reasons, the Chief Special

Master’s recognition that Ms. Beckwith’s proposed onset timeframe conflicted with the Table’s

timeframe was not an error of law.

The Chief Special Master ultimately determined Ms. Beckwith’s position was

“unsupported by sufficient reliable independent proof” and her expert medical opinions have

“reliability issues that [her] evidence did not fully address or refute.” Cerrone v. Sec’y of Health

& Hum. Servs., 146 F.4th 1113, 1124 (Fed. Cir. 2025) (quotation omitted). Specifically, the

medical literature Dr. Jeret and Dr. Akbari relied upon showed only “a temporal association”

between vaccination and early GBS onset in some cases and did not constitute evidence of

causation. Decision at 24. Further, the Chief Special Master concluded that the medical science

Dr. Akbari cited concerning vaccine-activated fast-acting ILLs and their impact on the

development of GBS was insufficiently developed or reliable to satisfy the preponderance of the

evidence standard under the third Althen prong. Id. at 25 (noting the difference between

plausibility and “a preponderant showing”). The Chief Special Master found the Secretary’s

experts and the evidence they relied upon more persuasive. Id. at 26. He noted their conclusions

were “consistent with the Table timeframe,” but his final conclusion did not rely solely on the

Table timeframe. Id. Thus, the Chief Special Master evaluated all the evidence against the

proper legal standard when he determined Ms. Beckwith “has not preponderantly established that

her GBS developed within a medically-acceptable timeframe after receipt of the flu vaccine.” Id.

at 21.

II. The Chief Special Master Properly Considered Ms. Beckwith’s Medical Theory

of Causation in Denying Her Claim Under the Third Althen Prong.

Ms. Beckwith further contends that the Chief Special Master erroneously failed to fully

evaluate her “modified theory of flu-vaccine caused GBS” under the first Althen prong and

therefore improperly “disregarded the etiology [she] proposed” to satisfy the timing requirement

under the third Althen prong. Mem. at 14–15. However, the Chief Special Master properly

recognized that the proposed “medically acceptable timeframe must align with the theory of how

the relevant vaccine can cause an injury (Althen prong one’s requirement).” Decision at 17

(citing de Bazan, 539 F.3d at 1352); see also Veryzer v. Sec’y of Health & Hum. Servs., 100 Fed.

Cl. 344, 356 (2011) (noting that “the temporal association must relate to the pathology of the

specific medical theory alleged to have caused the injury”), aff’d per curiam, 475 F. App’x 765

(Fed. Cir. 2012). Accordingly, the Chief Special Master evaluated Dr. Akbari’s theory of

causation, recognizing “it bears on whether Petitioner’s GBS began in a medically acceptable

timeframe.” Decision at 7. The Chief Special Master simply found Dr. Akbari’s theory

unpersuasive and insufficient to meet Ms. Beckwith’s burden under the third Althen prong. Id. at

24–26.

In evaluating the theory of causation, the Chief Special Master did not, as Ms. Beckwith

contends, “cl[ing] to the standard molecular mimicry theory without examining how the innate

immune system can trigger symptoms earlier through the inflammasome, ILCs, or ILLs.” Mem.

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at 14. Rather, the Chief Special Master thoroughly reviewed Dr. Akbari’s theory and

explanations to assess their reliability and credibility. See Decision at 7–8. The Chief Special

Master concluded that although Dr. Akbari “provided an explanation about how different aspects

of the immune response work (or are speculated to work in some faster contexts—such as with

ILLs), his opinion amounted to the contention that it was plausible that GBS could be triggered

in a shorter time than commonly understood.” Id. at 25. “[P]roof of a ‘plausible’ or ‘possible’

causal link between the vaccine and the injury . . . is not the statutory standard.” Moberly v.

Sec’y of Health & Hum. Servs., 592 F.3d 1315, 1322 (Fed. Cir. 2010); see also Boatmon v. Sec’y

of Health & Hum. Servs., 941 F.3d 1351, 1360 (Fed. Cir. 2019). Thus, the Chief Special Master

properly evaluated how the temporal association Ms. Beckwith 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. As further discussed

below, Ms. Beckwith’s other issues with the Chief Special Master’s evaluation of Dr. Akbari’s

medical theory amount to mere disagreement with the Chief Special Master’s credibility

determinations and factual conclusions, which this Court cannot second guess. See Hines, 940

F.2d at 1527.

III. The Chief Special Master Did Not Raise Ms. Beckwith’s Burden of Proof.

Ms. Beckwith next argues that the Chief Special Master erroneously “required [her]

prong 3 evidence to show that early onset was not legally probable, but scientifically or

medically certain, and required demonstration of a specific mechanism and a generally accepted

medical theory to establish a proximate temporal relationship.” Mem. at 16. Ms. Beckwith

contends this amounted to “requiring Ms. Beckwith to prove a Table revision is needed, rather

than that the vaccine was likely a substantial factor in her illness.” Id. at 17. Further, she asserts

that the Chief Special Master’s requirement she “explain the where and how of causation

constitutes a requirement of proof of mechanism, which is erroneous.” Id. (citing Althen, 418

F.3d at 1280). But the Chief Special Master did not err. Throughout his Decision, the Chief

Special Master “clearly articulated and applied the ‘more likely than not’ standard” to the third

Althen prong. White v. Sec’y of Health & Hum. Servs., No. 2024-1372, 2025 WL 3703259, at *5

(Fed. Cir. Aug. 27, 2025); see Decision at 21–26. Based on the record, he concluded “Petitioner

cannot show by preponderant evidence that her GBS began in a medically-acceptable

timeframe.” Decision at 26; see also id. at 23 (finding the “facts do not suggest a faster aberrant

immune response leading to GBS was more likely in Petitioner’s case (no matter how plausible

it might be), or did occur for the reasons alleged”).

The Chief Special Master did not require scientific or medical certainty anywhere in his

Decision. Nor did he require Ms. Beckwith to prove causation through “definitive statements of

causation and epidemiological certainty” so clear as to require that the Vaccine Table be revised.

Campbell, 97 Fed. Cl. at 673. When evaluating Ms. Beckwith’s medical opinions and the

underlying scientific literature, the Chief Special Master consistently differentiated evidence

indicating “GBS could occur in less than two days” after vaccination—a mere temporal

connection—from Ms. Beckwith’s burden to show it was “more likely than not” her GBS onset

occurred in a medically acceptable timeframe to infer the flu vaccine caused the injury. See

Decision at 24–26; see also Moberly, 592 F.3d at 1322 (differentiating between a “more likely

that not” standard and “proof of a ‘plausible’ or ‘possible’ causal link between the vaccine and

13

the injury, which is not the statutory standard”). He properly weighed the evidence, in line with

his authority as the factfinder, to determine its relevance and sufficiency for meeting Ms.

Beckwith’s burden of proof. See Bradley v. Sec’y of Health & Hum. Servs., 991 F.2d 1570, 1575

(Fed. Cir. 1993). As discussed above, he properly considered the Table timeframe along with

Ms. Beckwith’s evidence but ultimately found Ms. Beckwith failed to show that “her personal

health or other circumstances made a fast onset likely” in her particular case. Decision at 26; see

also Mager, 166 Fed. Cl. at 449 (finding it is proper for a special master to consider the Table

timeframe as “additional support”). Thus, he evaluated her claim of causation in fact “based on

the circumstances of the particular case.” Knudsen, 35 F.3d at 548.

Nor is the Chief Special Master’s conclusion that Dr. Akbari’s theory “does not identify

with enough reliable specific evidence where and how” Ms. Beckwith’s vaccination led her to

her GBS onset equivalent to an improper requirement of proof of mechanism. See Decision at

25. The Chief Special Master did not inappropriately “require identification and proof of

specific biological mechanisms” to satisfy the third Althen prong. See Althen, 418 F.3d at 1280

(citing Knudsen, 35 F.3d at 549). Rather, the Chief Special Master properly evaluated Dr.

Akbari’s opinion and the underlying evidence about fast-acting ILLs to determine whether it was

sufficiently credible and reliable for Ms. Beckwith to establish medical acceptability. See

Decision at 25. The Chief Special Master did not fault Ms. Beckwith for failing to provide proof

of specific biological mechanisms relating to ILLs. Instead, the Chief Special Master concluded

the theory Dr. Akbari offered only showed it was “plausible that GBS could be triggered in a

shorter time than commonly understood,” while acknowledging “need for greater understanding”

of how ILLs may contribute to that process. Id. at 8, 25–26. The Chief Special Master correctly

differentiated such evidence from a showing it is “more likely than not” true that in Ms.

Beckwith’s case flu-vaccine-triggered ILLs caused her GBS in less than two days. Id. at 25–26;

see Moberly, 592 F.3d at 1322.

IV. The Chief Special Master’s Factual Findings Were Neither Arbitrary Nor

Capricious.

Finally, Ms. Beckwith asserts that the Chief Special Master’s assessment of the evidence

was arbitrary and capricious, and he failed to articulate a rational basis for his Decision. See

Mem. at 18. She contends the Chief Special Master irrationally and implausibly evaluated the

scientific literature, improperly considered other potential causes of her GBS, ignored evidence

that overlapped with her causation theory under the first Althen prong, and improperly weighed

her evidence “against the Table” instead of “against the Althen requirements.” Id. at 18–20. But

Ms. Beckwith does not provide any basis for this Court to doubt the Chief Special Master’s

factual conclusions, which this Court must consider with special deference. Hodges, 9 F.3d at

961; see also Munn, 970 F.2d at 870 (noting the standard of review for factual findings is “the

most deferential possible”).

The record does not indicate that the Chief Special Master considered the scientific

literature irrationally or drew implausible conclusions. The Chief Special Master, within his

purview as the factfinder, considered all the scientific and medical literature Ms. Beckwith

submitted but found it unpersuasive. See Decision at 4–9, 23–26; Hines, 940 F.2d at 1528. He

rationally determined that the studies upon which her experts relied did not make sufficient

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findings about causation and merely showed a temporal connection between the flu vaccine and

GBS. See, e.g., id. at 5 (finding one study “ma[de] no determination about the relative risk

temporally from vaccination”), 6 (determining another study “did not reach conclusions about

more specific questions of temporal risk”), 25 (referencing a study that “does not stand for the

proposition that onset within a day or two of vaccination is as likely as within a week or more”);

see also Campbell, 97 Fed. Cl. at 668 (“Case reports do not purport to establish causation

definitively, and this deficiency does indeed reduce their evidentiary value compared particularly

to formal epidemiological studies.”). He also reasonably determined that the Park study, which

only documented payouts under the South Korean equivalent of the Vaccine Program, “could

reflect a policy decision” and was not sufficiently probative of whether it is medically acceptable

to infer the flu vaccine can cause GBS in less than two days. Decision at 24.3 Further, he

rationally discounted a study about the CNS, because “GBS is not a CNS disease.” Id. at 8. Ms.

Beckwith would prefer that this Court reevaluate the scientific and medical literature to reach a

different conclusion. But this Court cannot do so, particularly since this is a case “in which the

medical evidence of causation is in dispute.” Hodges, 9 F.3d at 961; see also Snyder, 88 Fed. Cl.

at 718.

The Chief Special Master also did not err when he speculated, without deciding, about

other potential causes of Ms. Beckwith’s GBS. While the Chief Special Master noted that her

ERCP or her URI may have been other reasonable causes of her GBS, see Decision at 23 n.16,

he only did so to illustrate Ms. Beckwith’s failure to meet her burden to establish it was

medically acceptable to infer the flu vaccine caused her GBS. Id. at 23. And to the extent Ms.

Beckwith now takes issue, for the first time, with the Chief Special Master’s failure to assess

whether her URI acted synergistically with the flu vaccine to cause her GBS, see Mem. at 12, she

waived this argument by failing to raise it below. See Austin v. Sec’y of Health & Hum. Servs.,

818 F. App’x 1005, 1008 (Fed. Cir. 2020) (A petitioner “cannot fault the Special Master for not

considering a piece of evidence she never presented to him”); McCollum v. Sec’y of Health &

Hum. Servs., 135 Fed. Cl. 735, 741 (2017) (“The Special Master cannot be expected to, sua

sponte, apply a legal theory that petitioner did not himself raise,” as this would “shift the burden

of proof from the petitioner to the Special Master himself.”), aff’d, 760 F. App’x 1003 (Fed. Cir.

2019).

Further, the Chief Special Master did not ignore the evidence Ms. Beckwith submitted

under the first Althen prong. He did not discuss every piece of evidence in his Decision but

stated that he reviewed all the evidence submitted in this case. See Decision at 20. A special

master need not “discuss every item of evidence in the record” when making a factual finding

“so long as the decision makes clear that the special master fully considered a party’s position

and arguments on point.” Snyder, 36 Fed. Cl. at 466.

3

Contrary to Ms. Beckwith’s suggestion, the Chief Special Master did not unreasonably

change his mind about the Park study; he similarly found in a previous case that “Park is not

entitled to great weight for the reliability of its medical findings” when rejecting a petitioner’s

claim under the third Althen prong. Block v. Sec’y of Health & Hum. Servs., No. 19-969V, 2021

WL 5709764, at *4 (Fed. Cl. Spec. Mstr. Oct. 29, 2021).

15

Nor did the Chief Special Master irrationally evaluate Ms. Beckwith’s causation theory

when denying her claim under the third Althen prong. As noted above, the Chief Special Master

thoroughly considered Dr. Akbari’s theory of causation and his view that flu vaccine-induced

ILLs can cause GBS onset within two days of vaccination, but simply found it lacked a reliable

scientific basis. Decision at 25 (finding Dr. Akbari’s theory “founders [sic] in implicating

vaccination as an ‘x factor’ leading to injury” and is “inadequately bulwarked with sufficient

reliable evidence”); see also Moberly, 592 F.3d at 1324 (“Although a Vaccine Act claimant is

not required to present proof of causation to the level of scientific certainty, the special master is

entitled to require some indicia of reliability to support the assertion of the expert witness.”).

The Chief Special Master noted that even Dr. Akbari acknowledged the shortcomings in

available literature, which meant “the science on this subject is far less firm than [Dr. Akbari]

implied.” Decision at 8. The Chief Special Master drew rational and plausible conclusions from

the evidence. Thus, this Court cannot “reweigh the factual evidence, [] assess whether the

Special Master correctly evaluated the evidence[,] . . . [or] examine the probative value of the

evidence.” Broekelschen, 618 F.3d at 1349 (citation omitted).

The Chief Special Master also properly weighed Dr. Akbari’s opinion against the

opinions of the Secretary’s experts, who disagreed that it was medically acceptable to infer Ms.

Beckwith’s flu vaccine caused her GBS onset, given how quickly it occurred in her case.

Decision at 26. He found the Secretary’s experts relied on robust evidence and were more

persuasive. Id. The Chief Special Master’s conclusion was “based on the credibility of the

experts and the relative persuasiveness of their competing theories.” Broekelschen, 618 F.3d at

1347 (citing Lampe, 219 F.3d at 1362). It is not appropriate for this Court to second-guess his

determinations about the persuasiveness of competing expert theories, id., which “are virtually

unchallengeable on appeal.” Lampe, 219 F.3d at 1362.

The Chief Special Master also noted that the Secretary’s experts’ theories were aligned

with the Table, see Decision at 26, but he did not, as Ms. Beckwith claims, weigh her evidence

against the Table. See Mem. at 20. Along with the competing expert theories and medical

literature, the Chief Special Master appropriately considered the science behind the onset

requirement for the GBS Table injury, see Flowers, 173 Fed. Cl. at 628–29, and his own

extensive experience with GBS cases. See Ultimo v. Sec’y of Health & Hum. Servs., 28 Fed. Cl.

148, 152–53 (1993); Doe v. Sec’y of Health & Hum. Servs., 76 Fed. Cl. 328, 338–39 (2007). He

rationally weighed the competing evidence and concluded Ms. Beckwith failed to meet her

burden, under Althen, to show by a preponderance of evidence that it was medically acceptable

to infer the flu vaccine caused her GBS onset in less than two days. Decision at 26. Since the

Chief Special Master’s Decision “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.” Cedillo, 617 F.3d at 1338.

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CONCLUSION

For the reasons articulated above, Ms. Beckwith’s Motion for Review, ECF No. 70, is

DENIED and the Chief Special Master’s Decision, ECF No. 67, is SUSTAINED. The Clerk of

the Court shall enter Judgment for Respondent accordingly.

Date: February 20, 2026

ROBIN M. MERIWEATHER

Judge

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