Court Opinion

ID: 9380855
Source: CourtListenerOpinion
Date Created: 2023-03-21 16:02:19.231156+00
Date Added: 2024-06-11T17:17:28.070688
License: Public Domain

In the United States Court of Federal Claims
                                  OFFICE OF SPECIAL MASTERS
                                            No. 18-944V
                                     Filed: February 21, 2023
                                            PUBLISHED

                                                                Special Master Horner
    CAMERON HARRIS,

                         Petitioner,                            Tetanus-diphtheria-acellular
    v.                                                          pertussis (“Tdap”) vaccine;
                                                                Meningococcal vaccine;
    SECRETARY OF HEALTH AND                                     Guillain-Barre Syndrome
    HUMAN SERVICES,                                             (“GBS”); Ruling on the record
                        Respondent.

Ronald Craig Homer, Conway, Homer, P.C., Boston, MA, for petitioner.
Christine M. Becer, U.S. Department of Justice, Washington, DC, for respondent.

                                    RULING ON ENTITLEMENT 1

       On June 29, 2018, petitioner, Cameron Harris, 2 filed a petition under the National
Childhood Vaccine Injury Act, 42 U.S.C. § 300aa-10-34 (2012), 3 alleging that his receipt
of tetanus-diphtheria-acellular pertussis (“Tdap”) and meningococcal vaccinations on
July 8, 2015, caused-in-fact his Guillain-Barre Syndrome (“GBS”). (ECF No. 1.) For the
reasons set forth below, I conclude that petitioner is entitled to compensation.

1
  Because this ruling contains a reasoned explanation for the special master’s action in this case, it will be
posted on the United States Court of Federal Claims’ website in accordance with the E-Government Act
of 2002. See 44 U.S.C. § 3501 note (2012) (Federal Management and Promotion of Electronic
Government Services). This means the ruling will be available to anyone with access to the
Internet. In accordance with Vaccine Rule 18(b), petitioner has 14 days to identify and move to redact
medical or other information the disclosure of which would constitute an unwarranted invasion of privacy.
If the special master, upon review, agrees that the identified material fits within this definition, it will be
redacted from public access.
2
  Petitioner was a minor when the petition was filed, so his mother filed the petition as his legal
representative. Cameron reached the age of majority during the pendency of this claim and was
substituted as petitioner on January 23, 2023. (ECF Nos. 78, 79.)

3
  Within this ruling, all citations to § 300aa will be the relevant sections of the Vaccine Act at 42 U.S.C.
§ 300aa-10-34.

                                                       1
   I.     Applicable Statutory Scheme

       Under the National Vaccine Injury Compensation Program, compensation
awards are made to individuals who have suffered injuries after receiving vaccines. In
general, to gain an award, a petitioner must make several factual demonstrations,
including showing that an individual received a vaccination covered by the statute;
received it in the United States; suffered a serious, long-standing injury; and has
received no previous award or settlement on account of the injury. Finally – and the key
question in most cases under the Program – the petitioner must also establish a causal
link between the vaccination and the injury. In some cases, the petitioner may simply
demonstrate the occurrence of what has been called a “Table Injury.” That is, it may be
shown that the vaccine recipient suffered an injury of the type enumerated in the
“Vaccine Injury Table,” corresponding to the vaccination in question, within an
applicable timeframe following the vaccination also specified in the Table. If so, the
Table Injury is presumed to have been caused by the vaccination, and the petitioner is
automatically entitled to compensation, unless it is affirmatively shown that the injury
was caused by some factor other than the vaccination. § 300aa-13(a)(1)(A); § 300 aa-
11(c)(1)(C)(i); § 300aa-14(a); § 300aa-13(a)(1)(B).

        In many cases, however, the vaccine recipient may have suffered an injury not of
the type covered in the Vaccine Injury Table. In such instances, an alternative means
exists to demonstrate entitlement to a Program award. That is, the petitioner may gain
an award by showing that the recipient’s injury was “caused-in-fact” by the vaccination
in question. § 300aa-13(a)(1)(B); § 300aa-11(c)(1)(C)(ii). In such a situation, of course,
the presumptions available under the Vaccine Injury Table are inoperative. The burden
is on the petitioner to introduce evidence demonstrating that the vaccination actually
caused the injury in question. Althen v. Sec’y of Health & Human Servs., 418 F.3d
1274, 1278 (Fed. Cir. 2005); Hines v. Sec’y of Health & Human Servs., 940 F.2d 1518,
1525 (Fed. Cir. 1991).

        The showing of “causation-in-fact” must satisfy the “preponderance of the
evidence” standard, the same standard ordinarily used in tort litigation. § 300aa-
13(a)(1)(A); see also Althen, 418 F.3d at 1279; Hines, 940 F.2d at 1525. Under that
standard, the petitioner must show that it is “more probable than not” that the
vaccination was the cause of the injury. Althen, 418 F.3d at 1279. The petitioner need
not show that the vaccination was the sole cause of the injury or condition, but must
demonstrate that the vaccination was at least a “substantial factor” in causing the
condition, and was a “but for” cause. Shyface v. Sec’y of Health & Human Servs., 165
F.3d 1344, 1352 (Fed. Cir. 1999). Thus, the petitioner must supply “proof of a logical
sequence of cause and effect showing that the vaccination was the reason for the
injury;” the logical sequence must be supported by “reputable medical or scientific
explanation, i.e., evidence in the form of scientific studies or expert medical testimony.”
Althen, 418 F.3d at 1278; Grant v. Sec’y of Health & Human Servs., 956 F.2d 1144,
1148 (Fed. Cir. 1992). Petitioner may not receive a Vaccine Program award based
solely on her assertions; rather, the petition must be supported by either medical
records or by the opinion of a competent physician. § 300aa-13(a)(1).

                                             2
       In what has become the predominant framing of this burden of proof, the Althen
court described the “causation-in-fact” standard, as follows:

         Concisely stated, [petitioner’s] burden is to show by preponderant
         evidence that the vaccination brought about her injury by providing: (1) a
         medical theory causally connecting the vaccination and the injury; (2) a
         logical sequence of cause and effect showing that the vaccination was the
         reason for the injury; and (3) a showing of proximate temporal relationship
         between vaccination and injury. If [petitioner] satisfies this burden, she is
         entitled to recover unless the [government] shows, also by a
         preponderance of the evidence, that the injury was in fact caused by
         factors unrelated to the vaccine.

Althen, 418 F.3d at 1278 (citations omitted). The Althen court noted that a petitioner
need not necessarily supply evidence from medical literature supporting her causation
contention, so long as the petitioner supplies the medical opinion of an expert. Id. at
1279-80. That expert’s opinion must be “sound and reliable.” Boatmon v. Sec’y of
Health & Human Servs., 941 F.3d 1351, 1359-60 (Fed. Cir. 2019) (citing Knudsen v.
Sec’y of Health & Human Servs., 35 F.3d 543, 548-49 (Fed. Cir. 1994)). The Althen
court also indicated, however, that a Program factfinder may rely upon “circumstantial
evidence,” which the court found to be consistent with the “system created by Congress,
in which close calls regarding causation are resolved in favor of injured claimants.” 418
F.3d at 1280.

       Generally, respondent bears the burden of demonstrating the presence of any
alternative cause by preponderant evidence only if petitioner satisfies his prima facie
burden. § 300aa-13(a)(1)(B); Walther v. Sec’y of Health & Human Servs., 485 F.3d
1146, 1150 (Fed. Cir. 2007). However, respondent may also present evidence relating
to an alternative cause to demonstrate the inadequacy of petitioner’s evidence
supporting his case in chief. Nonetheless, petitioner does not bear the burden of
eliminating alternative causes where the other evidence on causation is sufficient to
establish a prima facie case under Althen. de Bazan v. Sec’y of Health & Human
Servs., 539 F.3d 1347, 1352-53 (Fed. Cir. 2008); Walther, 485 F.3d at 1150.

   II.      Background Information Regarding GBS Cases in the Vaccine Program

        GBS is an acute-onset, monophasic, polyneuropathy. (A.K. Meena et al.,
Treatment Guidelines of Guillain-Barre Syndrome, 14 ANN. INDIAN ACAD. NEUROL. 1
(2011) (Ex. 20); Roger Baxter et al., Lack of Association of Guillain-Barre Syndrome
with Vaccinations, 57 CID 1 (2013) (Ex. II).) GBS is generally considered an
autoimmune condition and is associated with several triggers, including infections and
vaccination. (Baxter et al., supra, at Ex. II, p. 1.) Among published case series,
approximately two-thirds of all cases are preceded by a gastrointestinal or respiratory
infection within three months prior. (Id.; Allan Ropper et al., Guillain-Barre Syndrome
(Landry-Guillain-Barre-Strohl Syndrome, Acute Inflammatory Demyelinating

                                               3
Polyneuropathy, AIDP), In: Adams and Victor’s Principles of Neurology, 10th Ed.
MCGRAW-HILL 1322 (2014) (Ex. 21)).) Campylobacter jejuni (“c. jejuni”),
cytomegalovirus (CMV), Epstein-Barr virus, and Mycoplasma pneumoniae are known
precipitants of GBS. (Ropper et al., supra, at Ex. 21.) The infection most strongly
associated with GBS is c. jejuni. (Id.) There is also an extensive history of prior cases
in this program involving allegations that GBS was caused by vaccination, especially,
but not limited to, the flu vaccine.

       A small but significant increase in the number of GBS cases post-vaccination
was observed with the 1976 swine influenza vaccine. (Baxter et al., supra, at Ex. II, pp.
1-2.) An association was again later detected following the 2009 H1N1 monovalent
influenza vaccines in the United States. (Id.) These causal associations prompted the
2017 addition of GBS to the Vaccine Injury Table relative to the flu vaccine, though it is
not included for either the Tdap or meningococcal at issue in this case. National
Vaccine Injury Compensation Program: Revisions to the Vaccine Injury Table, 82 Fed.
Reg. 6294-01 (Jan. 19, 2017); see also 42 C.F.R. 100.3(a). Accordingly, unlike cases
involving the flu vaccine, petitioner must meet the above-discussed “causation-in-fact”
standard without the benefit of any causal presumption.

        Although the flu vaccine stands alone as being presumed to cause GBS within
this Program, cases have also concluded that some vaccines other than the flu vaccine
can cause GBS. Salmins v. Sec’y of Health & Human Servs., No. 11-140V, 2014 WL
1569478, at *14 (Fed. Cl. Spec. Mstr. Mar. 31, 2014) (accepting an expert opinion that
the HPV vaccine (Gardasil) “can cause” GBS although there was no published medical
literature demonstrating homology); Peugh v. Sec’y of Health and Human Servs., No.
99-38V, 2007 WL 1531666 (Fed. Cl. Spec. Mstr. May 8, 2007) (finding that the hepatitis
B vaccine caused GBS); 4 Koller v. Sec’y of Health & Human Servs., No. 16-439V, 2021
WL 5027947 (Fed. Cl. Spec. Mstr. Oct. 8, 2021) (finding that the pneumococcal vaccine
can cause GBS). 5

4
  On October 13-14, 2004, former Special Master Sweeney held a hearing—which became known as the
“Hepatitis B – Neurological Demyelinating Omnibus Proceeding”—to determine whether a causal
association exists between the Hepatitis B vaccine and several demyelinating illnesses (multiple
sclerosis, TM, chronic inflammatory demyelinating polyneuropathy, and GBS) alleged in four paradigm
cases. Stevens v. Sec’y of Health & Human Servs., No. 99-594V, 2006 WL 659525 (Fed. Cl. Spec. Mstr.
Feb. 24, 2006); Werderitsh v. Sec’y of Dept. of Health & Human Servs., No. 99-310V, 2006 WL 1672884
(Fed. Cl. Spec. Mstr. May 26, 2006); Peugh, 2007 WL 1531666; Gilbert v. Sec’y of Dept. of Health &
Human Servs., No. 04-455V, 2006 WL 1006612 (Fed. Cl. Spec. Mstr. Mar. 30, 2006). These cases were
then reassigned to former Special Master Laura Millman, who found that in all four cases, the Hepatitis B
vaccine was causal. Peugh, 2007 WL 1006612, at *1, *17-18.
5
 See also Pierson v. Sec’y of Health & Human Servs., No. 17-1136, 2022 WL 322836 (Fed. Cl. Spec.
Mstr. Jan. 19, 2022); Gross v. Sec’y of Health & Human Servs., No. 17-1075V, 2022 WL 9669651 (Fed.
Cl. Spec. Mstr. Sept. 22, 2022); Maloney v. Sec’y of Health & Human Servs., No. 19-1713V, 2022 WL
1074087 (Fed. Cl. Spec. Mstr. Mar. 17, 2022). But see Deshler v. Sec’y of Health & Human Servs., No.
16-1070V, 2020 WL 4593162 at *21 (Fed. Cl. Spec. Mstr. July 1, 2020); Bielak v. Sec’y of Health &
Humas Servs., No. 18-761V, 2023 WL 35509 (Fed. Cl. Spec. Mstr. Jan. 3, 2023).

                                                    4
        Notable to this case, however, there are conflicting decisions regarding whether
the Tdap vaccine can cause GBS. These decisions have been informed at least in part
by how this potential causal relationship has been viewed by the Institute of Medicine
(“IOM”) in two separate reports, both of which have been filed into the record of this
case by respondent. The Institute of Medicine (known as the National Academy of
Medicine since 2015) is the medical arm of the National Academy of Sciences. The
National Academy of Sciences (“NAS”) was created by Congress in 1863 to be an
advisor to the federal government on scientific and technical matters (see An Act to
Incorporate the National Academy of Sciences, ch. 111, 12 Stat. 806 (1863)), and the
Institute of Medicine is an offshoot of the NAS established in 1970 to provide advice
concerning medical issues. When Congress enacted the Vaccine Act in 1986, it
directed that the IOM conduct studies concerning potential causal relationships between
vaccines and illnesses. See § 300aa-1 note. Special masters have previously
observed that the IOM employs a standard for finding causation that is higher than what
is required by petitioner’s burden of proof. E.g., Raymo v. Sec’y of Health & Human
Servs., No. 11-654V, 2014 WL 1092274, at *21 n.39 (Fed. Cl. Spec. Mstr. Feb. 24,
2014). Accordingly, IOM reports and findings are typically approached with caution and
generally not treated as dispositive. Porter v. Sec’y of Health & Human Servs., 663
F.3d 1242, 1252 (Fed. Cir. 2011) (noting the special master’s comment that “IOM
reports are favored, although not dispositive, in the Vaccine Act Program,” then
affirming special master’s decision). However, numerous prior cases have
demonstrated that special masters may account for IOM findings in reaching their
decisions. 6

        In 1994, the IOM published a report indicating that “[t]here is biologic plausibility
for a causal relation between vaccines and demyelinating disorders.” (Kathleen Stratton
et al., Committee to Review Adverse Effects of Vaccines, Institute of Medicine, eds.,

6
  See, e.g., Crutchfield v. Sec’y Health & Human Servs., 125 Fed. Cl. 251, 262 (2014) (noting that “it was
appropriate for the special master to consider the medical literature presented, including the IOM report”
and that “the court often has relied on the findings of the Institute of Medicine”); see also Isaac v. Sec’y
Health & Human Servs., 108 Fed. Cl. 743, 755 (2013), aff’d, 540 Fed. App’x 999 (Mem.) (Fed. Cir. 2013)
(affirming the special master’s reliance on findings of the IOM); Cedillo v. Sec’y Health & Human Servs.,
No. 98-916V, 2010 WL 331968, at *94 (Fed. Cl. Spec. Mstr. Feb. 12, 2009), mot. for rev. denied, 89 Fed.
Cl. 158 (2009) (affirming the special master’s reliance on conclusions of IOM), aff'd, 617 F.3d 1328 (Fed.
Cir. 2010); Rodriguez v. Sec’y Health & Human Servs., 67 Fed. Cl. 409, 410 (2005) (relying on an IOM
report regarding vaccine causation of an injury); Althen v. Sec’y Health & Human Servs., No. 00-170V,
2003 WL 21439669, at *11 n.28 (Fed. Cl. Spec. Mstr. June 3, 2003) (“Due to the IOM’s statutory charge,
the scope of its review, and the cross-section of experts making up the committee reviewing the adverse
events associated with vaccines, the court considers their determinations authoritative and subject to
great deference.”), rev’d on other grounds, 58 Fed. Cl. 270, 272-74 (2003) (citing IOM reports frequently
in support of various scientific propositions), aff'd, 418 F.3d 1274 (Fed. Cir. 2005); Terran v. Sec’y Health
& Human Servs., 41 Fed. Cl. 330, 337 (1998) (affirming the special master’s reliance on conclusions of
IOM), aff'd, 195 F.3d 1302 (Fed. Cir.1999), cert. denied, 531 U.S. 812 (2000); Cucuras v. Sec’y Health &
Human Servs., 993 F.2d 1525, 1529 (Fed. Cir. 1993) (noting that the special master had placed “a great
deal of weight” on an IOM report in reaching a decision, then affirming the special master’s decision);
Stroud v. Sec’y Health & Human Servs., 113 F.3d 1258 (Fed. Cir. 1997) (unpublished) (special master
may rely upon an IOM report that neither party filed as evidence); Ultimo v. Sec’y Health & Human Servs.,
28 Fed. Cl. 148, 152 (1993) (proper for a special master to rely on IOM report).

                                                     5
Adverse Effects of Vaccines: Evidence and Causality, Washington (DC): National
Academies Press, p. 106 (1994) (Ex. G) (hereinafter “1994 IOM Report”).)
Furthermore, the report concluded that the evidence favors a causal relationship
between tetanus-containing vaccines and GBS. (Id. at 89.) The report indicated that in
addition to the biologic plausibility of vaccine-caused demyelination, this conclusion was
based on case reports, the most convincing of which was one by Pollard and Selby that
demonstrated challenge-rechallenge. 7 (Id.) Petitioner, in turn, has filed the Pollard and
Selby paper into this record. (See J.D. Pollard & G. Selby, Relapsing Neuropathy Due
to Tetanus Toxoid, 37 J. NEUROL. SCI. 113 (1978) (Ex. 33).) Subsequent cases alleging
GBS caused by tetanus vaccines generally found in petitioner’s favor. 8

         In 2012, however, the IOM issued a report that revisited this question. (Kathleen
Stratton et al., Committee to Review Adverse Effects of Vaccines, Institute of Medicine,
eds., Adverse Effects of Vaccines: Evidence and Causality, Washington (DC): National
Academies Press, p. 588 (2012) (Ex. E) (hereinafter “2012 IOM Report”).) The IOM
concluded in the 2012 report that the evidence was insufficient to accept or reject a
causal relationship between tetanus-containing vaccines and GBS. (Id.) This report
discussed the Pollard and Selby case report in the context of CIDP and was newly
critical of that report and other case reports for failing to adequately rule out alternative
causes. (Id. at 589-90.) Following this 2012 report, petitioners alleging GBS caused by
the tetanus vaccine saw mixed results in this program, with reasoned decisions tending
to reject causation, but many cases still compensated by stipulation (and thereby not
ultimately reaching the question of causation). 9 However, a more recent decision by
another special master examined this history in greater detail, along with additional

7
  The Federal Circuit has noted that “rechallenge” has been “recognized as a form of causation evidence.”
James-Cornelius v. Sec’y of Health & Human Servs., 984 F.3d 1374, 1380 (Fed. Cir. 2021) (citing
Capizzano v. Sec’y of Health & Human Servs., 440 F.3d 1317, 1322 (Fed. Cir. 2006)). In Capizzano, the
Federal Circuit explained that “[a] rechallenge event occurs when a patient who had an adverse reaction
to a vaccine suffers worsened symptoms after an additional injection of the vaccine. The chief special
master stated that this evidence of rechallenge constituted ‘such strong proof of causality that it is
unnecessary to determine the mechanism of cause—it is understood to be occurring.’” Capizzano, 440
F.3d at 1322.
8
  See Garcia v. Sec’y of Health & Human Servs., No. 05-720V, 2008 WL 5068934 (Fed. Cl. Spec. Mstr.
Nov. 12, 2008) (finding entitlement for petitioner’s claim that a Td vaccination caused his GBS); Watson v.
Sec’y of Health & Human Servs., No. 96-539V, 2001 WL 1682537 (Fed. Cl. Spec. Mstr. Dec. 18, 2001)
(ruling petitioner’s GBS was caused by the tetanus vaccine); Domeny v. Sec’y of Health & Human Servs.,
No. 94-1086V, 1999 WL 199059, at *41 (stating “the possibility that tetanus vaccine can cause GBS is not
an issue here because the court accepts that it can”). But see Tyson v. Sec’y of Health & Human Servs.,
No. 90-3379, 1999 WL 702562 (Fed. Cl. Spec. Mstr. Sept. 30, 1997) (finding against entitlement because
preponderant evidence did not support petitioner's claim that a tetanus toxoid-containing vaccine caused
his GBS).
9
 See Isaac v. Sec’y of Health & Human Servs., No. 08-601V, 2012 WL 3609993 (Fed. Cl. Spec. Mstr.
July 30, 2012), mot. rev. denied, 108 Fed Cl. 743 (2013), aff’d per curiam, 540 Fed. App’x 999 (Fed. Cir.
2013); Tompkins v. Sec’y of Health & Human Servs., No. 10-261V, 2013 WL 3498652 (Fed. Cl. Spec.
Mstr. June 21, 2013), mot. rev. denied, 117 Fed Cl. (2014); Rupert v. Sec’y of Health & Human Servs.,
No. 10-160V, 2014 WL 785256 (Fed. Cl. Spec. Mstr. Feb. 3, 2014). But see Mohamad v. Sec’y of Health
& Human Servs., No. 16-1075V, 2022 WL 711604 (Fed. Cl. Spec. Mstr. Jan. 27, 2022).

                                                    6
history regarding other relevant government statements on the subject, and found the
petitioner entitled to compensation for post-Tdap vaccine GBS. 10 Mohamad v. Sec’y of
Health & Human Servs., No. 16-1075V, 2022 WL 711604 (Fed. Cl. Spec. Mstr. Jan. 27,
2022).

        There are far fewer prior cases addressing whether the meningococcal vaccine
can cause GBS. In Whitener v. Secretary of Health & Human Services, a special
master found that the petitioner offered a plausible medical theory for how the
meningococcal vaccine can cause GBS. No. 06-0477V, 2009 WL 3007380, at *20
(Fed. Cl. Spec. Mstr. Sept. 2, 2009). Petitioner offered a 2005 CDC Morbidity and
Mortality Weekly Report (“MMWR”) dispatch health alert reporting five cases of GBS
following the meningococcal vaccine. Id. at 8, n.17. (An updated 2006 MMWR
regarding the same topic was filed by the petitioner in this case as Exhibit 17.) Although
the special master noted that there was no epidemiological evidence to support
causation, he found that the CDC’s MMWR dispatch article demonstrated at least an
incidental association. Id. at 20. Petitioner also relied on the 1994 IOM report’s
description of GBS as an immune-mediated disease to support the theory of causation.
Id. Given that petitioner suffered from an immune mediated autoimmune demyelinating
disease and that the MMWR dispatch “implicate[d] the meningococcal vaccine as one
vaccine for which this mechanism appears plausible,” the special master concluded that
petitioner offered preponderant evidence that the meningococcal vaccine can cause
GBS. Id. In a subsequent case, however, a different special master examined the
same underlying case reports and reached the opposite conclusion. 11 Tompkins v.

10
   In addition to the IOM reports discussed above, the Mohamad case also involved discussion of
recommendations by the Advisory Committee on Immunization Practices (“ACIP”), which is made up of
members selected by the Secretary of Health and Human Services to advise the Director of the Centers
for Disease Control, and testimony further expounding on the ACIP’s activities. Mohamad, 2022 WL
711604, at *9-10, 15-16. Relevant to the analysis in Mohamad, the ACIP issued a recommendation in
1996 that purported to find some “extremely low” risk for GBS following tetanus vaccination. (Id. at 11.)
Additionally, the ACIP issued additional recommendations in 2011, 2018, and 2019 that included a
precaution against tetanus vaccination for those who previously suffered GBS within six weeks of a prior
tetanus-containing vaccination. (Id. at 12, 14-15.) Considering the whole history of reports and actions
taken under the authority of the Secretary of Health and Human Services, the special master concluded
that the government’s acknowledgement of a post-vaccination risk satisfied petitioner’s burden of proof.
(Id. at 17-18.) Apart from the previously referenced IOM reports, none of these materials have been filed
into the record of this case.
11
   In Tompkins, the special master indicated that what the petitioner in that case had relied upon was only
a “news release from the U.S. Food & Drug Administration dated September 30, 2005” that included five
case reports. 2013 WL 3498652, at *26. However, in the earlier Whitener case, the special master
explained that petitioner’s expert in that case, Dr. Kinsbourne, had explained that the five case reports
were originally discussed in the September 30, 2005 FDA Health Alert, but that the same case reports
were addressed again in a later MMWR dispatch dated October 6, 2005. 2009 WL 3007380, at n.17.
Petitioner in that case relied specifically on the MMWR. According to the CDC’s website, the MMWR is
“the agency’s primary vehicle for scientific publication of timely, reliable, authoritative, accurate, objective,
and useful public health information and recommendations.” See About the Morbidity and Mortality
Weekly Report (MMWR) Series, CDC.GOV, www.cdc.gov/mmwr/about.html (last accessed Feb. 16,
2023). Thus, for example, in Mohamad, 2022 WL 711604, the special master explained that the MMWR
is the vehicle through which the ACIP recommendations discussed in n.10, supra, are publicized as
“official CDC/HHS recommendations to the general public.” 2022 WL 711604, at *10.

                                                        7
Sec’y of Health & Human Servs., No. 10-261V, 2013 WL 3498652, at *26 (Fed. Cl.
Spec. Mstr. June 21, 2013).

   III.   Procedural History

        As noted above, the petition was filed in this case on June 29, 2018. (ECF No.
1.) Initially it was assigned to Special Master Sanders. (ECF No. 4.) From that point
until September of 2018, petitioner filed medical records and affidavits marked as
Exhibits 1-14. (ECF Nos. 8-9, 12-14.) On September 27, 2018, petitioner filed an
amended petition specifying that Cameron suffered from the Miller Fisher variant of
GBS. (ECF No. 16.)

       Respondent filed his responsive Rule 4 Report on March 25, 2019. (ECF No.
22.) In his report, respondent acknowledged that several of petitioner’s treating
physicians attributed his GBS to his vaccinations, but raised two primary issues. First,
absent a causal presumption, petitioner could not establish that the vaccines at issue in
this case “can cause” GBS without an expert opinion. (Id. at 10.) Second, respondent
contended that the interval of onset of petitioner’s GBS was “too short” relative to
vaccination to be medically reasonable, contending that onset occurred less than 24
hours post-vaccination. (Id. at 11-12.) Respondent contended that the treating
physician opinions were limited to recognizing the coincident timing. (Id. at 10-11.)

       Following the filing of respondent’s report, petitioner filed an expert report by
neurologist Yuval Shafrir, M.D. (ECF No. 29; Ex. 15.) The report was accompanied by
a curriculum vitae (Ex. 16) and medical literature marked as Exhibits 17-64. (ECF Nos.
29-33.) Included within Dr. Shafrir’s assessment was a contention that onset of GBS
should be identified based on weakness, which occurred two days post-vaccination.
(Ex. 15, pp. 29, 35.)

       Shortly thereafter, the case was reassigned to my docket on August 29, 2019.
(ECF No. 36.) In a scheduling order issued September 24, 2019, I noted Dr. Shafrir’s
assessment of onset and observed that, contrary to respondent’s specific contention, it
appeared from the medical records that onset of numbness, tingling, and facial droop,
occurred just outside of 24 hours post-vaccination. (ECF No. 37.) I encouraged the
parties to consider litigative risk settlement. (Id.) Petitioner provided a demand to
respondent; however, respondent opted to file responsive expert reports rather than
commence settlement discussions. (ECF Nos. 37, 39-40.)

        On January 6, 2020, respondent filed expert reports by neurologist Leslie
Benson, M.D. (Ex. A (with curriculum vitae as Ex. B)) and immunologist Craig Platt,
M.D., Ph.D. (Ex. C (with curriculum vitae as Ex. D)). (ECF No. 41.) Respondent filed
accompanying medical literature marked as Exhibits E-QQ. (ECF No. 42.) In response,
petitioner filed an expert report by immunologist Omid Akbari, Ph.D., marked as Exhibit
65 along with a curriculum vitae (Ex. 66) and accompanying medical literature marked
as Exhibits 67-119. (ECF Nos. 47-52.) Respondent filed a supplemental report by Dr.

                                            8
Platt responding to Dr. Akbari’s report along with two additional supporting citations.
(ECF No. 55; Exs. RR-TT.)

       Subsequently, in a status report filed February 22, 2021, petitioner indicated that
Dr. Platt’s supplemental report did not raise any novel issues and therefore petitioner
did not intend to file any further supplemental expert reports. (ECF No. 56.) A follow up
status conference was held on May 5, 2021, to discuss how the case would proceed.
(ECF No. 60.) Petitioner then opted to proceed with a ruling on the written record in lieu
of scheduling an entitlement hearing. (ECF No. 65.) However, having reached that
conclusion, petitioner requested an opportunity to file supplemental expert reports to
address issues that would otherwise have been addressed by oral testimony. (Id.)

        On September 16, 2021, petitioner filed a supplemental report by Dr. Akbari
marked as Exhibit 120 and accompanying literature marked as Exhibits 121-134b.
(ECF Nos. 67-68.) Respondent filed a responsive report by Dr. Platt with one additional
citation. (ECF No. 71; Exs. UU-VV.) Petitioner filed her motion for a ruling on the
written record on February 9, 2022. (ECF No. 74.) Respondent filed a response on
April 18, 2022. (ECF No. 76.) Petitioner filed her reply on May 3, 2022. (ECF No. 77.)

       I have determined that the parties have had a full and fair opportunity to present
their cases and that it is appropriate to resolve this issue without a hearing. See
Vaccine Rule 8(d); Vaccine Rule 3(b)(2); Kreizenbeck v. Sec’y of Health & Human
Servs., 945 F.3d 1362, 1366 (Fed. Cir. 2020) (noting that “special masters must
determine that the record is comprehensive and fully developed before ruling on the
record”). Additionally, during the May 5, 2021, status conference I confirmed that
neither party objected to proceeding to a decision on the written record. (ECF No. 60.)
Accordingly, this matter is now ripe for resolution.

   IV.    Party Briefs and Issues to Be Decided

      In his motion for a ruling on the written record, petitioner stresses that there is no
debate in this case as to his GBS diagnosis. (ECF No. 74, pp. 33-34.) He further
contends that he has satisfied the three Althen prongs in order to demonstrate that his
GBS was caused by his July 8, 2015 vaccinations. (Id. at 31.)

       Petitioner relies on his experts’ opinions with respect to Althen prong one’s
requirement of a medical theory of causation. (Id. at 34-44.) He stresses that the
pathogenesis of GBS is multifactorial and that vaccination is among the “well-known”
triggers of GBS. (Id. at 34-35.) Petitioner’s arguments with respect to Althen prong one
span several lines of evidence discussed further below. (Id. at 34-44.)

        With regard to Althen prong two (a logical sequence of cause and effect),
petitioner stresses notations by his treating physicians accepting a causal relationship
between his GBS and his vaccinations and seeming to discount the possibility that the
GBS was related to a positive streptococcal culture. (ECF No. 74, pp. 44-51.)

                                             9
Petitioner further contends that the vaccinations would remain a substantial contributing
factor to his GBS even if infection additionally played a role. (Id. at 49-51.)

        Regarding Althen prong three (an appropriate temporal relationship), petitioner
argues that onset of his GBS, as evidenced by numbness and tingling, occurred more
than 24 hours post-vaccination, which therefore constitutes “day 2” in the relevant
literature. (Id. at 51.) Petitioner cites several pieces of literature that he contends
support a causal relationship based on this onset. (Id. at 51-54.) Further to this,
petitioner explains that his experts have set forth mechanistic evidence indicating,
based on immunological memory and cytokine response, why the rapid onset seen in
this case is appropriate. (Id. at 54-55.)

       Finally, petitioner contends that respondent has not met his burden of
establishing that petitioner’s GBS was caused by a factor unrelated to vaccination,
namely a streptococcal infection. (ECF No. 74, pp. 55-57.)

       In response, respondent argues that petitioner has failed to preponderantly
establish any of the three Althen prongs. (ECF No. 76.)

        Regarding Althen prong one, respondent contends that petitioner’s experts’
opinions are unreliable, stressing that these opinions mostly rely on case reports
(entitled to little weight) whereas larger epidemiologic studies do not support causation.
Respondent further charges that petitioner’s experts are misleadingly relying on an
outdated IOM report (the 1994 report) and haven’t substantiated the molecular mimicry
they theorize. (Id. at 12-14.)

       Regarding Althen prong two, respondent contends that there can be no logical
sequence of cause-and-effect implicating petitioner’s vaccinations, both because the
timing of onset is too short and because an infectious cause was not ruled out. (Id. at
14-15.)

        With respect to Althen prong three, respondent asserts that onset of petitioner’s
GBS occurred less than 24 hours after his vaccinations based on a competing
assessment of the onset of numbness and tingling. (Id. at 16.) Respondent contends
this is “not long enough for the manifestation of a systemic autoimmune response,
particularly where the response allegedly involves molecular mimicry and autoantibody
production.” (Id.)

       Respondent offered no assertion that he had met his burden of proof with respect
to establishing any factor unrelated to vaccination as the cause of petitioner’s GBS.

      Petitioner filed a reply disputing respondent’s assessment of the timeline of
onset. (ECF No. 77.) Petitioner also resisted respondent’s contention that her experts
had misleadingly relied on the earlier IOM report. (Id.)

                                            10
     V.      Factual Summary

             a. Vaccination and First Emergency Department Presentation

      Petitioner was born on December 9, 2003. (Ex. 2, p. 2.) Prior to the subject
vaccinations, the parties agree that petitioner was a healthy child with no history of
neurological issues or chronic health concerns. (ECF No. 74, p. 3; ECF No. 76, p. 2.)

        On July 8, 2015, petitioner saw Dr. Matthew Penson, his primary care physician,
for a routine physical. (Ex. 2, pp. 61-62.) At the time of his appointment, petitioner was
approximately eleven and a half years old. (Id.) The record of examination reflects
normal results and no significant concerns. (Id.) During this visit, petitioner received
the subject Tdap and meningococcal vaccines. 12 (Id.) In her affidavit, petitioner’s
mother recalls:

          The next day, July 9, 2015, I picked up [petitioner] from camp. When we got
          home, [petitioner] had something to eat and then said that he wanted to lie
          down. I asked him how he was feeling, and he said that he was tired and
          that his left arm was sore from the vaccines he received the day before.
          [Petitioner] napped for three hours on July 9, 2015, which was unusual for
          him. When he woke up, I asked him to open his eyes and he said that they
          were open, however, they were not. I waited for him to fully wake up, but
          after a few minutes, I noticed that his left eye was partially closed.
          [Petitioner] said that he did not feel very well and was extremely tired. I felt
          uneasy, so I decided to take him to the ER . . . .

(Ex. 13, pp. 1-2.)

        Petitioner presented to the Emergency Department (“ED”) at Joe DiMaggio
Children’s Hospital around 10:30 PM. (Ex. 4, pp. 5-8.) Petitioner’s mother reported that
he had received the Tdap and meningococcal vaccines the previous day, and “[s]hortly
after, he began having mild pain [in the] area of his arm where he received the vaccine.”
(Id. at 5.) She gave him ibuprofen for the pain and sent him to band camp for the day.
(Id.) When she picked him up from camp, he complained that his arm pain had
returned, so she gave him another dose of ibuprofen around 4:00 PM and he went to
sleep. (Id.) When he later awoke on July 9, 2015, she noticed that his left eyelid
appeared to be drooping, and he complained of tingling and numbness in his fingertips
bilaterally, extending to his wrists, and in his toes, extending to both feet. (Id.) Due to
cramping in his feet, he was unable to walk, and had to crawl toward his room. (Id.) He
also had the sensation that his feet were cold. (Id.) At the ED, his pain had resolved,
and he could walk normally, although the paresthesia persisted. (Id.)

12
   Although several records indicate that petitioner received a “DTaP” vaccine, according to petitioner’s
vaccination record he received “Tdap” (Adacel) and Meningococcal MCV4P (Menactra) vaccines on July
8, 2015. (Ex. 1, p. 2.)

                                                   11
        A physical examination was notable for left ptosis, but was otherwise normal,
with 5/5 strength, normal tone, intact sensation, and normal gait; reflexes were not
documented. (Ex. 4, p. 7.) A brain CT scan was unrevealing. (Id. at 17.) By around
midnight on July 9, 2015, the numbness and tingling had slightly improved, and he was
discharged home in the early morning hours of July 10, 2015, with diagnoses of ptosis
of the left eyelid and possible immunization reaction. (Id. at 7-8.)

            b. Inpatient Hospitalization July 10 – July 27, 2015

         On July 10, 2015, petitioner returned to the ER complaining of persistent pain in
his hands and the left side of his arm, and a burning sensation in his hands and feet.
(Ex. 4, pp. 33-39.) On examination, his ptosis was not visible, and he was able to stand
without difficulty but only after multiple distractions, due to his distress. 13 (Id. at 35, 38.)
He also was uncooperative with the measurement of extremity strength and the
elicitation of reflexes. (Id. at 38.) The ER physician ordered a lab work-up and MRI
studies, and consulted with several specialists, including those in neurology and
infectious disease. (Id. at 38-39.) The infectious disease specialist indicated that GBS
was not associated with the meningococcal vaccine. (Id. at 39.) The neurologist
admitted petitioner for a full evaluation. (Id.)

       Following admission, petitioner experienced worsening weakness, with loss of
reflexes, dysarthria, and ophthalmoplegia. (Ex. 4, pp. 42, 1819.) On July 11th, he was
placed in the IMCU for observation. (Id. at 49.) MRIs of the brain and spine were
negative. (Id. at 52-53.) An infectious disease consult noted that petitioner had been
camping in North Carolina for one week in June and then spent time with his
grandmother, where he swam and waterskied at a lake. (Id. at 58.) An examination
was notable for lateral third cranial nerve (oculomotor nerve) weakness, upper extremity
weakness, difficulty obtaining reflexes, and ataxia on the nose-to-finger test. (Id. at 59.)
Complete blood count (“CBC”), metabolic panel, and creatine phosphokinase (“CPK”)
were normal. (Id. at 60-61.) A lumbar puncture was performed and showed normal
indices. (Id. at 65.) The assessment was rule out Miller-Fisher variant of GBS, early
signs of amoebic encephalitis, or another neurologic condition. (Id. at 62.) Petitioner
began a four-day course of IVIG. (Id. at 66.)

       On July 13, 2015, petitioner’s condition had worsened, “with acute ascending
neuromuscular weakness likely GBS. Now committed to BiPAP, with neuromuscular
weakness that is progressing as expected. Expect will need mechanical ventilation.”
(Ex. 4, p. 107.) That same day, an immunologist asked for further details of petitioner’s
vacations prior to onset of his illness, including where he stayed and what he did during
those times. (Id. at 67.) On examination, petitioner was unable to speak, but could
follow commands. (Id. at 68.) He had bilateral ptosis and could not abduct his right
eye. (Id.) He was areflexic. (Id.) The impression was GBS. (Id. at 70.)

13
  The medical records indicate that petitioner was in moderate distress, intermittently agitated, and
crying. (Ex. 4, pp. 37-38.)

                                                    12
        Also on July 13, 2015, Dr. Matthew Penson submitted a report to the Vaccine
Adverse Event Reporting System (“VAERS”). (Ex. 9, pp. 1-2.) That same day Dr.
Martinez assessed petitioner with an “atypical case of GBS in view of symptoms and
[history] of vaccine in spite of labs[.] [Patient] has developed increasing weakness[,] loss
of [deep tendon reflexes,] and evidence of cranial nerve involvement . . . [Rule out]
infectious process or side effect secondary to vaccine[.] [Patient] was exposed to
bats[.]” (Ex. 4, pp. 108-11.) Dr. Martinez canceled NMDA testing as “this does not
appear[] to be NMDA encephalitis and add[ed] Enterovirus PCR to csf and West Nile
virus PCR[.]” (Id.) Dr. Martinez planned to repeat MRI of the brain and spine and
ordered an ophthalmology consult. (Id.)

        That same day, ophthalmologist Marien Leon, M.D., assessed petitioner with
GBS, with opthalmoparesis, possible Miller Fisher variant. (Ex. 4, p. 72.) Petitioner’s
exam findings were “suggestive of at least mild ophthalmoparesis. As his limitation in
abduction was worse [in both eyes] than in any other direction, conditions which cause
bilateral 6th nerve palsies such as Miller Fisher and increased intracranial pressure
should also be considered.” (Id.)

       On July 14, 2015, petitioner was intubated for respiratory failure with progressive
ascending weakness. (Ex. 4, p. 76.) Nerve conduction velocity (“NCV”) studies were
also done, with abnormal results in all nerves tested. (Ex. 11, pp. 1-4.) The findings
were consistent with a sensorimotor polyneuropathy with both axonal and demyelinating
features. (Id. at 2.) The presence of conduction blocks and temporal dispersion were
consistent with a diagnosis of acute inflammatory demyelinating polyneuropathy
(“AIDP”). (Id.)

        On July 15, 2015, repeat brain and spine imaging revealed small T2
hyperintense focus in the right frontal white matter not visible on prior MRI. (Ex. 4, p.
75.) It was thought to be nonspecific, “but may represent a small focus of
demyelination. No abnormal enhancement is seen.” (Id.) The spine MRI revealed mild
enhancement of the cauda equina roots in the lumbar regions, “that is either increased
or new in comparison with 7/10/15, and that is compatible with a given clinical diagnosis
of Guillain-Barre Syndrome.” (Id. at 619.) Petitioner had a positive throat swab for
streptococcus (“strep”). (Id. at 158.)

        On July 17, 2015, a neurology consult noted that petitioner was still intubated,
but his strength was improving slightly. (Ex. 4, p. 75.) He still had impaired eye
movement and areflexia. (Id.) Mild enhancement of the nerve root was noted in the
lumbar area on the MRI with contrast, and NCV studies showed both demyelinating and
axonal injury of the peripheral nerves. (Id.) The infectious work-up was negative to
date. (Id.) Neurology questioned whether a strep infection, which he apparently had
prior to this illness (and which his sister had shortly before he did) “may be the
causative factor in triggering this illness rather than viral infections or the immunization
he received before the illness occurred.” (Id.) An immunology consult suspected
vaccine associated atypical GBS, but similarly noted the positive strep as a possible
contributing factor in the development of GBS. (Id. at 200.)

                                             13
        On July 22, 2015, petitioner was extubated. (Ex. 4, pp. 266-68.) At this point,
petitioner had bilateral ptosis, right greater than left. (Id. at 266.) He could shrug his
shoulder, had 3+/5 strength in the upper extremities and 2/5 in the lower extremities,
could move his toes and his hands to midline and upwards, and had 2+ reflexes. (Id.)
On July 23, 2015, petitioner was transferred out of the ICU. (Id. at 284-85.) All viral and
bacterial cultures remained negative, except for evidence of strep throat. (Id.) The
latest imaging results were consistent with GBS, and “an IgG GM 1 antibody positive
[was] also indicative of peripheral neuropathic disease. Per immunology and infectious
disease, process is likely related to the Menactra vaccination the child received
approximately a week ago [sic]. Report has been made to the vaccine adverse event
system.” (Id.)

        On July 27, 2015, petitioner was discharged to rehabilitation. (Ex. 4, pp. 41-44.)
Discharge diagnoses included GBS “following vaccination,” respiratory failure,
paresthesia, dysesthesia, and Miller Fisher variant GBS. (Id. at 42.) Over the course of
petitioner’s hospitalization his throat culture was positive for Group A Strep and he
received a course of Clindamycin; completed a course of Doxycycline to cover for tick-
born pathogens; and his viral and bacterial cultures including CSF were all negative.
(Id. at 43.)

          c. Inpatient Rehabilitation July 27 – August 14, 2015

       On July 27, 2015, petitioner began inpatient rehabilitation, with physical,
occupational, and speech therapies. (Ex. 4, pp. 1815-18.) He was admitted with
weakness, deficits in mobility and activities of daily living (“ADLs”), and dysesthetic pain.
(Id.) At discharge on August 14, 2015, petitioner was independent with ADLs and was
walking both with and without a walker, with mild gait deviations. (Ex. 4, pp. 1816-17.)
He could navigate stairs with a railing and did not need to wear his ankle-foot orthotics.
(Id.) He was able to eat and drink without difficulty. (Id.) His discharge examination
was notable for mild right ptosis, tight hamstrings, and gait abnormality. (Id.) His
strength was generally improved, but he had ongoing core weakness. (Id.) He was to
receive physical therapy three times per week and occupational therapy twice per week.
(Id.)

          d. Treatment Following Discharge from Inpatient Rehabilitation

        On August 28, 2015, petitioner had his first rehabilitation follow-up. (Ex. 6, pp.
35-45.) His strength was mostly 5/5, with some decrease in the upper extremities, but
he continued to improve. (Id. at 41.) At a neurology follow-up on October 5, 2015,
petitioner was doing well, but reported tiring easily, especially in the mornings in school.
(Ex. 5, pp. 139-40.) He was still receiving physical and occupational therapy. (Id.) He
continued to have burning pain in his arms and ankles, for which he was taking
medication as needed. (Id.) On examination, he had normal cranial nerves, and normal
muscle tone and extremity strength, but his deep tendon reflexes were diffusely absent.
(Id.) Petitioner’s gait and balance were normal, with the ability to stand on one leg and
hop. (Id.)

                                             14
         At an October 28, 2015 rehabilitation follow-up, petitioner reportedly was less
tired, but he still required rest during the school day. (Ex. 6, pp. 153-58.) He had no
sensory deficits and had normal muscle tone and normal coordination. (Id.) He had
diminished heel strike on the left, intermittently, but continued to improve overall. (Id.)
petitioner was discharged from occupational therapy on October 30, 2015. (Ex. 8, pp.
1054-58.) He had met all his short-term goals and 75-100 percent of his long-term
goals. (Id. at 1057.) He was to work on overall endurance and upper extremity strength
and independence. (Id. at 1058.) On November 18, 2015, petitioner saw Dr. Penson,
who noted that his GBS and symptoms were improving, although he still had mild
decreased reflexes. (Ex. 2, pp. 17-20.) Subsequently petitioner returned to the Boy
Scouts. (Id.)

       That same day, petitioner also had a neurology follow-up. (Ex. 7, pp. 106-07.)
He was doing well from a motor standpoint but complained of pains in his back and legs
at the end of the day. (Id.) He also had brief headaches. (Id.) However, he had
recently walked for over two hours with his family on Halloween, was able to go to the
store with his mother without complaints and had gone on some retreats with the Boy
Scouts. (Id.) He also had been exercising with a bike and receiving physical therapy.
(Id.) On examination, he had decreased reflexes, but normal sensation. (Ex. 7, p. 107.)
His gait was normal, and he could walk and squat without problem; however, he had
mild decreased dexterity and difficulty hopping on either leg alone. (Id.)

       A physical therapy progress note dated December 2, 2015, reflects that petitioner
had started playing football in the neighborhood and was cleared to return to school
sports. (Ex. 8, p. 1106.) Petitioner still reported pain with intense exercise, and fatigue
with long periods of standing or walking. (Id.) Petitioner also had gait deviations with
longer walks. (Id.) He was encouraged to continue physical therapy. (Id.) On January
25, 2016, a VAERS report was completed by Sanofi Pasteur, the manufacturer of the
vaccines. (Ex. 9, pp. 21-23.) The report concludes that “further information on the
confirmation of the diagnosis, patient medical history, as well as etiological infectious
work-up for this pathology . . . are needed to further assess this case. Moreover, the
patient received two vaccines simultaneously making it difficult to assess the role of
each vaccine in particular.” (Id. at 23.)

      Petitioner was discharged from physical therapy on February 3, 2016, nearly
seven months after the onset of his GBS. (Ex. 2, pp. 52-57.) On that date he was
independent and had met 90 percent of his rehabilitation goals. (Id. at 56.) He was
discharged to a home exercise program. (Id.)

        On February 24, 2016, petitioner had a neurology follow-up. (Ex. 2, pp. 45-50.)
He reportedly was able to walk, hop, and jump, and run at least a quarter-mile. (Id.) He
still experienced tiredness and had some “high level balance issues” (e.g., unable to
balance on a skateboard or steer his bike as well as he used to). (Id.) He denied
paresthesia and dysesthesia. (Id.) His physical exam was essentially normal, except
for hyporeflexia. (Id.) On June 7, 2016, petitioner had another neurology follow-up.

                                            15
(Ex. 7, pp. 128-29.) It was now eleven months after onset of GBS and he had made an
excellent recovery. (Id.) A detailed examination was normal except for some gross
motor incoordination with hopping on either foot alone. (Id.) He had intermittent
discomfort in his limbs, which he treated with Advil. (Id.) His prognosis was good. (Id.)

      On July 12, 2016, Dr. Penson received a one-year follow-up letter from VAERS
asking for information on petitioner’s current condition. (Ex. 2, pp. 38-39.) Dr. Penson
responded that petitioner had recovered from the adverse event and was “much better,
discharged from physical therapy. Still has neuropathies  weaning meds.” (Id.) On
August 15, 2016, petitioner had a twelve-year-old check-up, with no major concerns
noted. (Ex. 2, pp. 11-15.) He was doing well, but still had occasional pain. (Id.) He
had been discharged from neurology. (Id.) His physical examination, which included a
neurological assessment, was normal. (Id. at 12.)

        On August 16, 2017, about two years after GBS onset, petitioner had a thirteen-
year-old check-up, with no major concerns noted. (Ex. 2, pp. 5-9.) Petitioner was
participating in physical activities, and aside from being overweight, his examination
was normal, including musculoskeletal and neurological assessments. (Id.)

     VI.    Expert Opinions

            a. Petitioner’s Neurologist, Yuval Shafrir, M.D. 14

       Petitioner filed one report by neurologist Yuval Shafrir, M.D. (Ex. 15.) Dr. Shafrir
notes that petitioner did have some early reaction to vaccination unrelated to GBS in the
form of arm soreness and tiredness. (Id. at 30.) However, he places onset of the GBS
as occurring on July 9, 2015, more than 24 hours post-vaccination. (Id.) This timing
derives from the onset of weakness that occurred after petitioner’s first ER presentation
following his ptosis and which led to his hospital admission the next day. Dr. Shafrir
opines that petitioner’s initial post-vaccination ptosis followed a different clinical
trajectory from the other cranial nerve involvement seen as part of his GBS and was
more likely a separate cranial nerve palsy than a symptom of his later diagnosed
GBS. 15 (Id.)

14
   Dr. Shafrir received his medical degree from the Sackler School of Medicine at Tel Aviv University in
1982. (Ex. 16, p. 1.) He completed his residency in pediatrics at North Shore University Hospital in
Manhasset, New York and his pediatric neurology residency and fellowship at the Washington University
Medical Center in St. Louis, Missouri. (Id.) In 1992 Dr. Shafrir completed his pediatric neurophysiology
and epileptology fellowship at Miami Children’s Hospital. (Id.) He is board certified in neurology with a
special qualification in child neurology as well as clinical neurophysiology. (Id. at 2.) Dr. Shafrir began
his own neurology practice in May 2000, where he currently serves as a pediatric neurologist. (Id. at 3.)
He currently serves as an assistant professor in the Department of Pediatrics for the University of
Maryland School of Medicine in Baltimore Maryland. (Id.) He also teaches residents and medical
students at Sinai Hospital, Department of Pediatrics. (Ex. 16, p. 3.) Dr. Shafrif has co-authored several
publications in various neurology journals, though none on GBS or polyneuropathy specifically. (See id.
at 3-5.)
15
   Dr. Shafrir explains that ptosis is a form of 3rd cranial nerve palsy. Citing a prior review paper by Woo,
et al., he suggests that such isolated nerve palsies have been documented in the Vaccine Adverse

                                                     16
        Dr. Shafrir explains that petitioner’s presentation was atypical, which initially
confused his treating physicians. 16 (Ex. 15, pp. 30-31.) He notes that the treating
physicians initially included infectious causes in their differential diagnosis, particularly
streptococcal throat infection, but suggests that post-vaccination GBS was the ultimate
diagnosis. (Id. at 31.) He opines that an infectious etiology is less likely. Given the
rapidity of onset, it is very unlikely that any nerve inflammation predated petitioner’s
vaccinations. Additionally, workup for an infectious etiology was negative except for a
strep infection. However, petitioner did not show any signs of strep infection until after
being intubated and streptococcal infection is not a common precedent for GBS. (Id.)

        Dr. Shafrir acknowledges that Vaccine Injury Table includes a three-day
minimum latency for GBS caused by the flu vaccine but discusses a number of factors
which he suggests may explain the quicker onset in this case. (Ex. 15, pp. 36-37.)
First, individual genetic differences may affect both susceptibility and antibody
production. (Id.) Second, GBS, though generally understood to be an autoimmune
condition stemming from the adaptive immune response, also has a cytokine driven
innate immune aspect. (Id. at 32-33.) For example, Dr. Shafrir cites a meta-analysis of
30 prior studies comprising 1,302 GBS patients and 1,073 health controls. (Ting Sun et
al., Peripheral Blood and Cerebrospinal Fluid Cytokine Levels in Guillain Barre
Syndrome: A Systematic Review and Meta-Analysis, 13 FRONT. NEUROSCI. 1 (2019) (Ex.
47)).) The meta-analysis found that tumor necrosis factor (“TNF”) alpha, interleukin
(“IL”) 1-beta, Il-6, IL-4, IL-17, and interferon gamma, are significantly elevated among
GBS patients. (Id. at 1.) The authors hypothesize that these findings are pathologic in
GBS, noting in particular that prior study has shown T-cell produced TNF-alpha to have
a direct myelinotoxic effect on myelinated fibers. (Id. at 5-6.) Dr. Shafrir suggests that
the AIDP form of GBS that petitioner suffered is more T-cell dependent than the AMAN
form of GBS, which is more antibody dependent. (Ex. 15, p. 33.)

        Dr. Shafrir suggests that petitioner’s own history suggests a number of reasons
to believe there was “prominent” activation of post-vaccination cytokines. (Ex. 15, p.
37.) He notes petitioner’s initial localized reaction to the vaccination and cites literature
indicating that the fifth dose of DTaP immunization has been showed to cause cytokine-

Events Reporting System (“VAERS”) as consequences of vaccination. (Ex. 15, p. 30 (citing Emily Jane
Woo et al., Motor Palsies of Cranial Nerves (Excluding VII) After Vaccination. Reports to the US Vaccine
Adverse Event Reporting System, 10 HUM. VACCINE IMMUNOTHER. 301 (2014) (Ex. 19)).) Dr. Shafrir notes
that Woo et al., identified a minimum timing to onset of 0.3 days. (Id.) Woo et al., includes cases as far
out as 3,285 days (i.e., nine years), but indicates that the median timing of onset was 9 days. (Ex. 19, p.
3.) Thus, Dr. Shfarir opines that petitioner’s ptosis may have been an independent consequence of
vaccination. (Ex. 15, p. 30.)
16
   Specifically, Dr. Shafrir cites the following unusual factors: earlier prominent involvement of the cranial
nerve, presence of anti-GM1 IgG antibodies, presence of white blood cells but no elevated protein in the
spinal tap, intact deep tendon reflexes even after onset of weakness and inability to walk, rapid recovery
of deep tendon reflexes, severe pain upon initial presentation, and demyelination in the brain. (Ex. 15,
pp. 30-31.)

                                                      17
related local reactions more often than earlier doses. 17 (Id. (citing Danuta Skowronski
et al., Injection-Site Reactions to Booster Doses of Acellular Pertussis Vaccine: Rate,
Severity, and Anticipated Impact, 112 PEDIATRICS 1 (2003) (Ex. 63)).) Thus, Dr. Shafrir
notes for example that in contrast to the three-day latency between the flu vaccine and
the peripheral nerve damage seen in GBS, the Vaccine Injury Table includes a lesser
48-hour onset period for brachial neuritis following tetanus vaccine—brachial neuritis
being another form of immune mediated peripheral nerve disorder. (Id. at 37.)
Moreover, petitioner was also simultaneously administered the Menactra vaccine, which
is conjugated using the diphtheria toxoid and contains six times as much of the toxoid
as typical Td vaccines. Menactra has been shown to be substantially more
immunogenic than Td vaccines alone. (Ex. 15, p. 35 (quoting Tejpratap Tiwari &
Melinda Wharton, Diphtheria Toxoid, In: Vaccines, 6th Ed, Edited by Stanley A. Plotkin
et al., ELSEVIER INC., 21 (2012) (Ex. 42)).) Further, petitioner had pain, malaise and
fatigue before onset of other signs of GBS, which are very likely cytokine-mediated
symptoms. 18 (Id. at 37-38.) Dr. Shafrir suggests that the pro-inflammatory cytokines
associated with the DTaP vaccine, including IL-6, interferon gamma, and TNF alpha,
are also elevated in GBS. (Id. at 38.)

      Dr. Shafrir indicates that immunizations broadly are “a well-known trigger” for
GBS. (Ex. 15, p. 32.) He cites the influenza vaccination as having an established
causative relationship and further stresses that “almost every known febrile infection
and immunization has at one time or another been reported to precede GBS (some
probably coincidental).” (Id. (quoting Allan Ropper et al., Guillain-Barre Syndrome
(Landry-Guillain-Barre-Strohl Syndrome, Acute Inflammatory Demyelinating
Polyneuropathy, AIDP), In: Adams and Victor’s Principles of Neurology, 10th Ed.
MCGRAW-HILL 1322, 1324 (Ex. 21)).) Dr. Shafrir cites two papers for the proposition

17
  The study compared children who received a fifth consecutive dose of acellular pertussis vaccine
against those who received a mixed series that include some whole-cell pertussis vaccinations. They
reported more injection site reactions in the former group. Petitioner’s records show that on July 8, 2015,
he received an “Adacel” vaccination. (Ex. 2, p. 3.) Adacel is a Tdap vaccine for ages ten to 64. See
Adacel, FDA.GOV, www.fda.gov/vaccines-blood-biologics/vaccines/adacel (last accessed Feb. 17, 2023).
Petitioner previously received a complete five dose series of “Daptacel” vaccinations on February 10,
2004, April 12, 2004, June 22, 2004, June 16, 2005, and March 13, 2009. (Ex. 2, p. 3.) Daptacel is a
diphtheria tetanus and acellular pertussis vaccine given to children between six weeks and 6 years of
age. See Daptacel, FDA.GOV, www.fda.gov/vaccines-blood-biologics/vaccines/daptacel (last accessed
Feb. 17, 2023).
18
   Dr. Shafrir stresses that the pain of GBS in particular has been associated with cytokines. He cites a
paper evaluating a previously conducted study. The paper indicates that the underlying article identifies
two types of pain associated with GBS, pain starting before onset of weakness that is mainly radicular
muscle pain of the extremities and chronic arthralgia of the limbs associated with weakness and disability.
(Thirugnanam Umapathi & Nobuhiro Yuki, Pain in Guillain-Barre Syndrome, 11 EXPERT REV. NEUROTHER.
335, 338 (2011) (Ex. 64).) Regarding the former, the study hypothesized that “neuropathic pain, where
inflamed or damages large myelinated sensory fibers may lead to the dysesthesia, as well as the muscle
pain in the extremities. This may explain the correlation of pain with severity of illness at nadir in the acute
phase.” (Id.) Furthermore, “[a]nimal studies have suggested a role for T-cell mediated inflammation and
the release of proinflammatory cytokines producing thermal hyperalgesia and allodynia in experimental
autoimmune neuritis.” (Id.)

                                                      18
that about 10% of hospitalized GBS patients had a preceding immunization, noting in
particular that a Canadian study of children found tetanus-containing vaccinations to be
the most common preceding immunization. Meningococcal vaccine also preceded
several cases. 19 (Id. (citing Karina Top et al., Guillain Barre Syndrome After
Immunization in Canadian Children (1996-2012), 34 PEDIATR. INFECT. DIS. J. 1411 (Ex.
23); Joachim Schessl et al., Infections and Vaccinations Preceding Childhood Guillain-
Barre Syndrome: A Prospective Study, 165 EUR. J. PEDIATR. 506 (2006) (Ex. 24)).)

       Dr. Shafrir cites a number of case reports identifying post-tetanus vaccine GBS.
(Ex. 15, pp. 33-33 (citing Kannikar Kongbunkiat et al., Clinical Manifestations and
Outcomes of Guillain-Barre Syndrome After Diphtheria and Tetanus Vaccine (dT)
During a Diphtheria Outbreak in Thailand: A Case Series, 19 NEUROL. ASIA 137 (2014)
(Ex. 28); Rohit Bakshi & Michael Graves, Guillain-Barre Syndrome After Combined
Tetanus-Diphtheria Toxoid Vaccination, 147 J. NEUROL. SCI. 201 (1997) (Ex. 29);
Hussam Ammar, Guillain-Barre Syndrome After Tetanus Toxoid, Reduced Diphtheria
Toxoid and Acellular Pertussis Vaccine: A Case Report, 5 J. MED. CASE REP. 1 (2011)
(Ex. 30); Norris Newton Jr. & Abdorassol Janati, Guillain-Barre Syndrome After
Vaccination with Purified Tetanus Toxoid, 80 SOUTH MED. J. 1053 (1987) (Ex. 31); W.
Baust et al., Peripheral Neuropathy After Administration of Tetanus Toxoid, 222 J.
NEUROL. 131 (1979) (Ex. 32); J.D. Pollar & G. Selby, Relapsing Neuropathy Due to
Tetanus Toxoid, 37 J. NEUROL. SCI. 113 (1978) (Ex. 33)).) He also cites a study finding
an increased risk of CIDP relapse following tetanus vaccination. (J. Pritchard et al., The
Risk of Relapse of Guillain-Barre Syndrome or Chronic Inflammatory Demyelinating
Polyradiculo-Neuropathy Following Immunization, 73 J. NEUROL. NEUROSURG.
PSYCHIATRY 348 (2002) (Ex. 34).) That study screened 1,114 patients with either GBS
or CIDP for reports of neurological symptoms post-vaccination. (Id. at 348.) Most of the
patients, 927, suffered GBS, while an additional 179 suffered CIDP. Of those patients,
311 reported having received a vaccine subsequent to developing GBS and 65 reported
having received a vaccine subsequent to developing CIDP. Of those vaccinated
patients, 11 of the GBS patients and five of the CIDP patients reported a relapse in
symptoms. (Id. at 349-50.) Overall, the authors concluded that the risk of relapse was
“low” and stressed that many more patients received the same vaccines without
relapse. (Id. at 350.) However, while cautioning that the sample size for CIDP cases

19
   The Canadian study by Top et al., examined 246 hospitalizations between 1996 and 2012, finding 24
cases where onset occurred within 30 days of an immunization. (Top et al., supra, at Ex. 23, p. 1411.)
Among those cases, 19 cases had a single preceding vaccination, including diphtheria-tetanus-pertussis
vaccine and influenza vaccine each in five cases respectively, various hepatitis B vaccines in four cases,
meningococcal vaccine in three cases, and MMR vaccine in two cases. (Id. at 1412.) Among cases with
co-administered vaccines, DPT was present in four cases and meningococcal was present in one. (Id.)
Thus, Dr. Shafrir notes that tetanus-containing vaccine was the most frequently observed vaccine in the
study. (Ex. 15, p. 32.) Importantly, however, the study authors note that a majority of these post-
vaccination cases also had symptoms of recent infection, with 21% having microbiologically confirmed
infection. (Top et al., supra, at Ex. 23, p. 1412.) The authors conclude the temporal association
observed between vaccination and immunization is “most likely coincidental.” (Id. at 1413.) The other
study cited by Dr. Shafrir, Schessl et al., examined 84 cases of GBS among children and found that eight
cases had preceding vaccinations; however, as with Top et al., they observed that a majority of those
children, six of eight, had concomitant infections. (Schessl et al., supra, at Ex. 24, p. 605.)

                                                    19
was small, the authors indicated that among the CIDP patients “[o]f greatest concern is
the risk of relapse following tetanus toxoid, which was 8.7% (95% CL 1.7%, 28.9%) in
our patient sample. In view of these figures and previous reports of relapse of CIDP
following tetanus toxoid patients may wish to avoid routine tetanus toxoid
immunization.” (Id.) Additionally, given that influenza vaccine is well accepted in this
program as a cause of GBS, it is very interesting to note that among this population
there were relatively higher rates of relapse following tetanus vaccine among both GBS
and CIDP patients than there were following influenza vaccination. 20 (Id. at 349 (Table
1).) Given this, Dr. Shafrir cites several sources that suggest that tetanus toxoid is
generally considered a risk factor for CIDP relapse. (Ex. 15, p. 34 (citing Robert
Hadden & Richard Hughes, Management of Inflammatory Neuropathies, 74 J. NEUROL.
NEUROSURG. PSYCHIATRY 1 (2003) (Ex. 35); Malcolm Rabie & Yoram Nevo, Childhood
Acute and Chronic Immune-Mediated Polyradiculoneuropathies, 13(3) EUR. J. PAEDIATR.
NEUROL. 209 (2009); Richard A.C. Hughes et al., Immunisation and Risk of Relapse of
Guillain-Barre Syndrome or Chronic Inflammatory Demyelinating
Polyradiculoneuropathy, 19 MUSCLE & NERVE 1230 (1996) (Ex. 37)).)

        Further to this, Dr. Shafrir explains that tetanus disease is itself associated with
peripheral neuropathies generally and GBS specifically has been documented as a
complication. (Ex. 15, pp. 34-35 (citing Manik Shahani et al., Neuropathy in Tetanus, 43
J. NEUROL. SCI. 173 (1979) (Ex. 38); Jae Hoon Lee et al., Generalized Tetanus Could
Be Complicated with Guillain-Barre Syndrome, 48 INTL. J. INFECT. DIS. 20 (2016) (Ex.
39)).) The IOM recognizes the effects of a natural infection as one type “albeit minor” of
mechanistic evidence potentially supportive of vaccine causation, though “[e]vidence
consisting only of parallels with the natural infections is never sufficient.” (2012 IOM
Report, supra, at Ex. E, p. 13.) Dr. Shafrir further stresses, for example, that the
Vaccine Injury Table recognizes tetanus vaccines as a cause of brachial neuritis. 21 (Id.
at 33.)

      Finally, Dr. Shafrir relies on several regulatory warnings as evidence supporting a
causal relationship between GBS and both the Tdap and meningococcal vaccines. The
vaccine package inserts for both of the vaccines petitioner received, Adacel and

20
  Specifically, among GBS patients, 8 out of 2011 patients who received a flu vaccine and 6 out of 105
patients who received a tetanus vaccine reported a relapse. That works out to 3.8% and 5.7% of
vaccinated patients respectively, a higher percentage for the tetanus vaccine. Likewise, among CIDP
patients, 2 out of 46 patients who received a flu vaccine reported a relapse whereas the same number of
patients who received a tetanus vaccine reported a relapse despite half as many patients (23) having
received a tetanus vaccine. Thus, 4.3% of flu vaccine receipts and 8.7% of tetanus vaccine recipients
suffered a relapse. (Pritchard et al., supra, at Ex. 34, p. 349 (Table 1).)
21
   In the 1994 IOM report filed by respondent, the IOM explained that two large case series had found a
significant portion of subjects suffered brachial neuritis temporally related to a tetanus toxoid vaccine.
(1994 IOM Report, supra, at Ex. G.) The IOM noted that the mechanism of brachial neuritis is not well
understood, but that the case series were sufficient to extrapolate an excess risk for brachial neuritis
following vaccine administration as compared to background rates. (Id.) Therefore, the committee
concluded that “evidence favors acceptance of a causal relation between tetanus toxoid and brachial
neuritis.” (Id. at 112.)

                                                     20
Menactra, include a warning that persons previously diagnosed with GBS may be at
increased risk of GBS following receipt of the vaccine. 22 (Menactra, Meningococcal
Polysaccharide Diphtheria Toxoid Conjugate Vaccine, Package Insert, Sanofi Pasteur,
pp. 44-5 (Ex. 44) (hereinafter “Menactra Package Insert”); Adacel, Tetanus Toxoid,
Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Package Insert, Sanofi
Pasteur, p. 4 (Ex. 48) (hereinafter “Adacel Package Insert”).) Additionally, the CDC
advised in an October 20, 2006 MMWR that case reports exist to indicate “a possible
association” between meningococcal vaccine and GBS. 23 (Update: Guillain-Barre
Syndrome Among Recipients of Menactra Meningococcal Conjugate Vaccine—United
States, June 2005-Septemeber 2006, 55 MMWR WKLY. 1120 (Ex. 17) (hereinafter
“Menactra CDC Report”).) Dr. Shafrir notes that Australia’s regulatory agency has
added GBS as a contraindication for administration of Menactra. (Australian Public
Assessment Report for Groups A, C, Y and W-135 Meningococcal Polysaccharide

22
    The warning included in the Adacel package insert is based on the 1994 IOM report that found
evidence to support a causal relationship between tetanus toxoid and GBS, as previously discussed in
prior cases such as Mohamad, 2022 WL 711604. (Adacel Package Insert, supra, at Ex. 48, p. 4.) Adacel
was initially approved in 2005, prior to the publication of the 2012 IOM report that revisited that
conclusion. (Id. at 2.) Notably, however, the package insert filed in this case includes a notation
regarding “recent major changes” that confirms the warnings and precautions section of the insert was
updated in September of 2017. (Id.) The update that was made appears to relate to latex allergies. (Id.
at 2, 4.) GBS was identified as an adverse reaction in post marketing experiencing but was not
specifically addressed in the clinical trials. As of August 6, 2021, the most recent Vaccine Information
Statement by the CDC continues to indicate, consistent with the warning contained in the Adacel
prescribing information, that those considering at DTaP vaccine should talk with their healthcare provider
before receiving the vaccine if they have ever had GBS. DTaP (Diphtheria, Tetanus, Pertussis) Vaccine:
What You Need to Know, CDC, www.cdc.gov/vaccines/hcp/vis/vis-statements/dtap.pdf (last accessed on
Feb, 17, 2023). The warning included in the Menactra insert is based on a prior MMWR from 2006, which
petitioner has separately filed as Exhibit 17, and which is an update to the MMWR previously discussed in
Whitener, 2009 WL 3007380, as well as a 2010 study by Harvard Medical School. The details of the
Harvard study are not discussed in the insert and no author or publication are listed. Respondent has
filed a 2012 paper by researchers affiliated with Harvard/Pilgrim that found no association between
meningococcal vaccine and GBS. (Priscilla Velentgas et al., Risk of Guillain-Barre Syndrome After
Meningococcal Conjugate Vaccination, 21 PHARMACOEPIDEMIOLOGY & DRUG SAFETY 1350 (2012) (Ex.
CC).) As with Adacel, GBS is included within the post marketing experience for Menactra; however, the
risk of GBS was also evaluated in a retrospective cohort study that found no instances of Menactra
having been administered within 42 days of symptom onset. (Menactra Package Insert, supra, at Ex. 44,
p. 22.)
23
   This was based on VAERS case reports of GBS occurring within six weeks of vaccination. A prior
MMWR had reported eight cases occurring between June and July of 2005. The October 2006 MMWR
reported nine additional cases occurring between March and September of 2006. (Menatrca CDC
Report, supra, at Ex. 17, p. 1.) The CDC compared 15 confirmed GBS cases in persons aged 11-19 and
compared that against the 5.39 million vaccine doses administered and determined a rate of 0.20 cases
of GBS per 100,000 person-months. To determine a background rate, the CDC used data from the
Healthcare Cost and Utilization Project (HCUP), and estimated incidence of GBS of 0.11 per 100,000
person-months. Thus, the ratio of post-meningococcal vaccine GBS was 1.78 compared to the
background rate with a 95% confidence interval of 1.02-2.85. (Id. at 3.) However, when the same
calculation was done using information from the Vaccine Safety Database to determine the background
rate, the result did not reach statistical significance. (Id. at 3-4.) The report notes that “substantial
uncertainty exists regarding the risk estimate” and that a larger study would be necessary to reach a more
definitive conclusion. (Id. at 4.)

                                                   21
Diphtheria Toxoid Conjugate Vaccine, TPA, pp. 87-88,
https://www.tga.gov.au/sites/default/files/auspar-menactra-110929.pdf (Ex. 18).)

            b. Petitioner’s Immunologist, Omid Akbari, Ph.D. 24

       Petitioner filed two reports by immunologist Omid Akbari. (Exs. 65, 120.) Dr.
Akrbari presents a theory of molecular mimicry, which he defines as “the mechanism by
which an immune stimulated response by infection or other method, i.e., vaccination,
can trigger cross-reactive T cells that cause the symptoms of autoimmune disease.”
(Ex. 65, p. 3.) Theories of molecular mimicry are most often supported by a
demonstrated sequence homology and evidence of cross-reaction. (Id. at 3-8.)
However, Dr. Akbari stresses that showing an identical or homologous sequence has a
shared level of identity to a human protein implicated in a pathogenic process is only
one possible method of implicating molecular mimicry as the mechanism involved in
causing an autoimmune disease like GBS. (Id. at 9.)

       Traditionally, immunologists have classified immune responses into two
mechanisms: innate and adaptive. (Ex. 65, p. 5.) However, Dr. Akbari stresses that
newly identified cells under the category of Innate Like Lymphocytes (ILL), consisting of
several members including fast-acting NKT cells, Innate Like Lymphocytes (ILCs), and
gamma delta T cells. (Id. (citing Luc Van Kaer et al., Innate, Innate-Like and Adaptive
Lymphocytes in the Pathogenesis of MS and EAE, 16(6) CELL. MOL. IMMUNOL. 531
(2019) (Ex. 79); Lewis Lanier, Shades of Grey—The Blurring View of Innate and
Adaptive Immunity, 13 NAT. REV. IMMUNOL. 73 (20130 (Ex. 80); Christopher Klose &
David Artis, Innate Lymphoid Cells Control Signaling Circuits to Regulate Tissue-
Specific Immunity, 30 CELL RES. 475 (2020) (Ex. 81)).) These cells, Dr. Akbari explains,
are fast acting cells that can produce cytokines and cause protection or cause
pathologies within hours. (Ex. 65, pp. 5-6.) Studies on other ILLs, including gamma-
delta T cells and NKT cells, suggest that there are “no clear boundaries between innate
and adaptive immunity.” (Id. (citing Van Kaer et al., supra, at Ex. 79).) Dr. Akbari notes
that ILLs have not previously been considered key participants in the early immune
response; however, many recent observations suggest their involvement of these fast-
acting immune cells in induction of demyelinating diseases, like GBS. (Ex. 65, p. 6.)
For example, he suggests that activated gamma delta T cells in GBS patients may be

24
   Dr. Akbari received in his Master of Science in medical and general microbiology from the University
College London. (Ex. 66, p. 1.) He received his Ph.D. in cellular and molecular immunology from the
National Institute for Medical Research in London. (Id.) Dr. Akbari currently serves as a professor of
medicine and professor of allergy and immunology at the Keck School of Medicine, University of Southern
California. (Ex. 65, p. 2.) He also serves as an adjunct professor in the department of pediatrics at the
David Geffen School of Medicine at UCLA and holds an active adjunct professorship in the department of
immunology with Chiba University in Japan. (Id.) His research focuses on “the role of immune cells that
induce autoimmune and allergic diseases.” (Id.) Dr. Akbari’s work has been published in the New
England Journal of Medicine, Nature Immunology, Nature Medicine, Nature Communications, Immunity
and Journal of Clinical Investigation. (Id.) He has received several national and international grants,
including from the National Institute of Health. (Id.) Dr. Akbari serves as a reviewer for more than 25
research journals and has served on several NIH study sections involving Vaccines, Immunization,
Allergy and Immunology research. (Ex. 65, p. 3.)

                                                   22
activated by the recognition of non-protein antigens in an MHC-unrestricted manner and
contribute to the immune response to glycolipids that is a hallmark of GBS. (Id. (citing
Giovanna Borsellino et al., Phenotypic and Functional Properties of ɣδ T Cells from
Patients with Guillain Barre Syndrome, 102 J. NEUROIMMUNOL. 199 (2000) (Ex. 82)).)
Borsellino et al. concluded that the Vδ1 subset of gamma delta T cells was the most
prevalent in GBS, as it has been found to be at three times its normal numbers in
patients. (Ex. 120, p. 3 (citing Borsellino et al., supra, at Ex. 82).)

       Alternatively, Dr. Akbari proposes another member of these fast-acting ILLs—the
innate ILCs. (Ex. 120, p. 3.) ILCs lack a recombined antigen receptor and are poised to
produce interferon-gamma or T helper 2 (TH2) and TH17 cell-associated cytokines
following stimulation. (Id.) Dr. Akbari relies on two studies. The first is a study showing
that ILC2s are able to cause demyelination in a mouse model of MS. (Id. (citing Satoshi
Hirose et al., Type 2 Innate Lymphoid Cells Induce CNS Demyelination in an HSV-IL-2
Mouse Model of Multiple Sclerosis, 23 ISCIENCE 1 (2020) (Ex. 127)).) Dr. Akbari
stresses that ILCs have been shown to exert a profound influence in CNS inflammatory
disease and as these cells are residents within the nervous system, they can be
activated early in disease to express a wide variety of disease-modifying cytokines and
chemokines. (Ex. 120, p. 3 (citing Melissa A. Brown & Rebecca B. Weinberg, Mast
Cells and Innate Lymphoid Cells: Underappreciated Players in CNS Autoimmune
Demyelinating Disease, 9 FRONT. IMMUNOL. 1 (2018) (Ex. 83)).) A second study cited by
Dr. Akbari showed that a subset of fast acting-ILCs expressing T-bet greatly influenced
the development of demyelinating and autoimmune disease. (Ex. 120, p. 3 (citing
Brandon Kwong et al., Author Correction: T-bet-dependent NKp46(+) Innate Lymphoid
Cells Regulate the Onset of TH17-Induced Neuroinflammation, 18 NAT. IMMUNOL. 1
(2018) (Ex. 84)).)

         Dr. Akbari explains that current tetanus vaccines are made using the inactivated
tetanus toxin, termed tetanus toxoid, and are extremely effective in generating serum
anti-toxin antibodies which protect against the highly potent neurotoxin released upon
infection by Clostridium tetani. (Ex. 65, p. 12.) Exposure of tetanus toxin to formalin or
formaldehyde and Lysine solutions is the current method for preparation in vaccine
manufacturing, which Dr. Akbari explains inactivates the toxin in a manner which leaves
the native conformation of the protein stable. (Id.) He opines that tetanus toxin and
tetanus toxoid are known to bind to cell surface gangliosides in the nervous system and
mutational analysis of the toxin protein has shown that the binding properties of tetanus
to gangliosides and to neuronal cells is due to the Hc chain (heavy chain) of the protein.
(Id. (citing Rui Yu et al., A Conformational Change of C Fragment of Tetanus Neurotoxin
Reduces Its Ganglioside-Binding Activity but Does Not Destroy Its Immunogenicity, 18
CLIN. VACCINE IMMUNOL. 1668 (2011) (Ex. 109); JJ Farrar et al., Tetanus, 69 J. NEUROL.
NEUROSURG. PSYCHIATRY 292 (2000) (Ex. 110)).)

      According to Dr. Akbari, several studies have shown that tetanus toxoid
molecules are antigenically complex and capable of cross-reactivity with various
biomolecules including DNA and bacterial toxins. (Ex. 65, p. 12 (citing Aleksandra Inic-
Kanada et al., Murine Monoclonal Antibody 26 Raised Against Tetanus Toxoid Cross-

                                            23
Reacts with Beta2-Glycoprotein I: Its Characteristics and Role in Molecular Mimicry, 61
AM. J. REPROD. IMMUNOL. 39 (2006) (Ex. 111); Behzod Dolimbek et al., Cross Reaction
of Tetanus and Botulinum Neurotoxins A and B and the Boosting Effect of Botulinum
Neurotoxins A and B on a Primary Anti-Tetanus Antibody Response, 31 IMMUNOL.
INVEST. 247 (2002) (Ex. 112); P. Kursula, Structural Properties of Proteins Specific to
the Myelin Sheath, 34 AMINO ACIDS 175 (2008) (Ex. 113)).) He cites one study where
human volunteers were given booster immunizations to diphtheria and tetanus
vaccines, and serum samples were collected one-week post immunization. (Ex. 65, pp.
12-13.) Analysis of human monoclonal antibodies derived from those blood samples
showed that the antibodies collected from people one-week post-immunization were
capable of cross-reacting to epitopes from self-antigens as well as to antigens derived
from tetanus and diphtheria toxoid. (Id.) Dr. Akbari stresses that this study proves that
antibodies derived from immunization with tetanus toxoid and diphtheria toxoids are
capable of binding to self-antigens. (Id. (citing Dolimbek et al., supra, at Ex. 112;
Kursula, supra, at Ex. 113).) Moreover, a study from Volk et al. determined that the
tetanus toxoid consists of at least 20 different distinct sites (epitopes) that can be
recognized by the immune system. (Ex. 65, p. 13 (citing W.A. Volk et al., Neutralization
of Tetanus Toxin by Distinct Monoclonal Antibodies Binding to Multiple Epitopes on the
Toxin Molecule, 45 INFECT. IMMUN. 604 (1984) (Ex. 114)).)

       Dr. Akbari’s opinion focuses on the ability of the tetanus toxoid to cross-react with
known pathogenic molecules already identified in GBS patients. He does not address
the research showing that the diphtheria or pertussis components of the vaccine could
also result in an adverse cross-reaction; however, he opines that this is also plausible.
(Ex. 65, p. 13.) He cites a study using BLAST which revealed that myelin P0 has
sequence and structural similarity to the diphtheria toxin, among other putative
pathogens. (Id. (citing Deena Vardhini et al., Comparative Proteomics of the
Mycobacterium Leprae Binding Protein Myelin P0: Its Implication in Leprosy and Other
Neurodegenerative Diseases, 4 INFECT. GENET. EVOL. 21 (2004) (Ex. 115)).) According
to Dr. Akbari, this research implicates other components of the vaccines as well in the
pathogenesis of GBS. (Ex. 65, p. 13.)

        In response to Dr. Platt, Dr. Akbari opines that the literature describing the quick
onset of ILLs or memory cells supports the 24-hour onset in petitioner’s case. (Ex. 120,
p. 5.) For instance, Dr. Akbari notes that a recent study showed that inflammatory
neuropathies display disease and subtype-specific alterations of CSF cell composition
and increased number of memory lymphocytes and ILLs (including NKT cells) play a
major role in the acute onset of GBS. (Id. (citing Michael Heming et al., Immune Cell
Profiling of the Cerebrospinal Fluid Provides Pathogenetic Insights into Inflammatory
Neuropathies, 10 FRONT. IMMUNOL. 1 (2019) (Ex. 85)).) Other GBS literature supports a
quick onset as well. (Laura Polakowski et al., Chart Confirmed Guillain-Barre Syndrome
After 2009 H1N1 Influenza Vaccination Among the Medicare Population, 2009-2010,
178 AM. J. EPIDEMIOL. 962 (2013) (Ex. 129); Silvia Perez-Vilar et al., Guillain-Barre
Syndrome After High-Dose Influenza Vaccine Administration in the United States, 2018-
2019 Season, 223 J. INFECT. DIS. 416 (2021) (Ex. 130)).) Perez-Vilar et al. found that
97.9% of cases developed GBS symptoms within 3 weeks post-vaccination and more

                                            24
than half of cases (54.2%) occurred within 0-2 days after vaccination. (Ex. 120, p. 5
(citing Perez-Vilar et al., supra, at Ex. 130, Figure 2C).)

            c. Respondent’s Neurologist, Leslie Benson, M.D. 25

        Respondent filed one expert report from Dr. Benson. (Ex. A.) Dr. Benson opines
that all of petitioner’s symptoms, including ptosis, extremity paresthesia, weakness and
progressive areflexia are consistent with his diagnosis of GBS. (Ex. A, p. 4.) However,
Dr. Benson stresses that the timing of onset is not medically appropriate for vaccine-
causation where petitioner’s GBS onset occurred less than 24 hours after his subject
vaccinations. Instead, Dr. Benson opines that petitioner’s neurological symptoms
began with pain in his hands on July 9th around 12:00 PM and progressed to unilateral
ptosis later in the same day. (Id. at 1 (citing Ex. 4, p. 43, 50, 56, 64, 73.) Dr. Benson
stresses that pain and paresthesia are common in childhood GBS. (Ex. A, p. 5.) She
stresses that paresthesia is a common initial (34%) and later (79%) manifestation of
pediatric GBS. (Id. (citing Monique Ryan, Epidemiology, Clinical Features, and
Diagnosis of Guillain-Barre Syndrome in Children, UPTODATE 1 (2019) (Ex. T); Hugh
Willison et al., Guillain-Barre Syndrome, 388 LANCET 717 (2016) (Ex. V)).) Thus,
petitioner’s neuropathic pain and paresthesia are the initial manifestations of petitioner’s
GBS.

       Dr. Benson opines that petitioner’s ptosis is a manifestation of his GBS and Miller
Fisher syndrome and is not a separate vaccine reaction. (Ex. A, p. 5.) Dr. Benson
explains that ptosis is a form of ophthalmoparesis that can be associated with forms of
GBS. (Id. (citing Mazen Dimachkie & Richard Barohn, Guillain-Barre Syndrome and
Variants, 31 NEUROL. CLIN. 491 (2013) (Ex. K); Ryan, supra, at Ex. T).) In petitioner’s
case his ptosis did evolve into frank ophthalmoparesis, as documented by his
ophthalmologist, which all fits with the evolution of ocular manifestations of GBS. (Ex.
A, p. 5 (citing Ex. 4, p. 73).)

       Dr. Benson contends that current scientific evidence supports no relationship
between Menactra or Tdap vaccinations and GBS. (Ex. A, p. 5.) While there is some
link between the older 1976 influenza vaccine and post-vaccination GBS, Dr. Benson
stresses that the link between infection and GBS is clearly much stronger. (Id. (citing
Lamiae Grimaldi-Bensouda et al., Guillain-Barre Syndrome, Influenzalike Illnesses, and
Influenza Vaccination During Seasons with and Without Circulating A/H1N1 Viruses,
174 AM. J. EPIDEMIOL. 1 (2011) (Ex. Z); Nicola Principi & Susanna Esposito, Vaccine-
Preventable Diseases, Vaccines, and Guillain-Barre Syndrome, 37 VACCINE 5544

25
  Dr. Benson received her Bachelor of Science degree from Colorado State University and her M.D. from
the University of Colorado Health Sciences Center. (Ex. B.) She is a pediatric neurology board certified
physician with subspecialty fellowship training in neuro-immunology, licensed to practice medicine in the
state of Massachusetts. (Ex. A, p. 1.) She is the assistant director of the multiple sclerosis and related
disorders and neuro-immunology clinics at Boston Children’s Hospital. (Id.) She has authored /
coauthored thirty-seven peer reviewed articles and three chapters and three review articles regarding
pediatric neuroinflammatory disease. (Id.) She treats children with neuroinflammatory diseases in both
the inpatient and outpatient settings. (Id.)

                                                   25
(2019) (Ex. AA)).) She stresses that MCV, tetanus, diphtheria and pertussis have been
“only coincidentally linked to GBS with no causal association based on the latest
literature.” (Ex. A, p. 5.) Dr. Benson suggests that “[a]lthough long term, large scale
data looking for vaccine associated complications for both vaccines that [petitioner]
received exists, Dr. Shafrir presents predominantly small scale, basic science, old data
and case reports to support his arguments.” (Id.) Dr. Benson also discounts the value
of the VAERS report filed in petitioner’s case because petitioner’s “ID physician notified
multiple state health departments due to public health concern, similar to [a] report to
VAERs.” (Id.) She stresses that it is a physician’s duty to consider alternative
diagnoses and triggers, and in both instances petitioner’s physicians were “covering
their bases while evaluating the possibilities.” (Id. (citing Ex. 4, pp. 140-141).)

        For the Menactra vaccine specifically, Dr. Benson stresses that the initial reports
of post-vaccination GBS occurred within 1.5 to 5 weeks of vaccination after the vaccine
was approved in 2005. (Ex. A, p. 5.) This led to warnings via MMWR reports. (Id.)
However, she stresses that large scale follow-up studies have not found a true
association between GBS and meningococcal vaccination. (Id.) In fact, Dr. Benson
emphasizes the warning was removed in 2011. (Id. (citing Michael Apicella,
Meningococcal Vaccines, UPTODATE 1 (2018) (Ex. BB); Priscilla Velentgas et al., Risk
of Guillain-Barre Syndrome After Meningococcal Conjugate Vaccination, 21
PHARMACOEPIDEMIOL. & DRUG SAF. 1350 (2012) (Ex. CC); Tanya Myers & Michael
McNeil, Current Safety Issues with Quadrivalent Meningococcal Conjugate Vaccines,
14 HUM. VACCIN. & IMMUNOTHER. 1175 (2018) (Ex. DD)).)

        For the Tdap vaccine, Dr. Benson notes that the 1978 Pollard case of recurrent
neuropathy following booster immunization received attention for a possible vaccine-
specific GBS trigger. (Ex. A, p. 6.) However, a follow-up study in 1997 examined the
predicted baseline incidence of GBS among children (2.4 cases) compared to the actual
incidence found within a DTP vaccination cohort (2 cases within 6 weeks of
vaccination). (Id. (citing Jessica Tuttle et al., The Risk of Guillain-Barre Syndrome After
Tetanus-Toxoid-Containing Vaccines in Adults and Children in the United States, 87
AM. J. PUBLIC HEALTH 2045 (1997) (Ex. KK)).) Dr. Benson suggests that the rate of GBS
in that study among those receiving vaccination “was actually lower than expected in
both adults and children cohorts.” (Id.) Moreover, the Pollard case was reclassified
from GBS to CIDP by the IOM in 2012. (Ex. A, p. 6 (citing IOM Report 2012, supra, at
Ex. E).)

      Dr. Benson further stresses that the time between vaccinations to symptom onset
was less than 24 hours. (Ex. A, p. 6.) She insists that “[l]ess than 24 hours is not long
enough for manifestation of a systemic auto-immune response, particularly one of
molecular mimicry and antibody production.” (Id.) The Adams and Victor textbook
observes that “infection or immunization precedes the neuropathic symptoms by 1 to 3
weeks in approximately 60 percent of cases . . . almost every known febrile infection
and immunization has at one time or another been reported to precede GBS (some
probably coincidentally).” (Id. (quoting Ropper et al., supra, at Ex. 21).) While another
source cites a median interval from vaccination to symptom onset of 18 days, with a

                                            26
range of 4-30 days. (Ex. A, p. 6 (citing Top et al., supra, at Ex. 23).) Dr. Benson
concludes that the references provided from Dr. Shafrir are outdated single case reports
“which do not offer good assessment of causality” or focus on an alternative disease
CIDP. (Ex. A, pp. 6-7.)

        Lastly, Dr. Benson suggests that the lack of infectious work-up precludes
eliminating infection as an inciting trigger in petitioner’s case. (Ex. A, p. 7.) Dr. Benson
acknowledges that there is no documentation of prior infectious symptoms prior to
petitioner’s GBS onset, but she stresses that tests were not done to rule out c. jejuni or
EBV. (Id.) She observes that EBV can be asymptomatic and cause transaminitis. (Id.)
In petitioner’s case, Dr. Benson opines that his transaminitis may have been related to
illness / medications in the ICU, however an infectious etiology for petitioner’s GBS
cannot be ruled out. (Id.) According to Dr. Benson, the significance of the positive
throat culture for strep “is uncertain in this case.” (Id.) She suggests that “[t]here have
been a few reported cases of Miller Fisher syndrome associated with strep” though it is
not a common pathogen listed in association with GBS. (Ex. A, p. 7.) “That said, like
those 2 cases, that infection triggered [petitioner’s] GBS.” (Id.) She notes that Dr.
Brown likewise posited this theory. (Id. (citing Ex. 4, p. 619).)

            d. Respondent’s Immunologist, Craig D. Platt, M.D., Ph.D. 26

         Respondent filed three expert reports from Dr. Platt. (Exs. C, RR, UU.) Dr.
Platt’s first report responds to Dr. Shafrir’s expert report and offers many of the same
points made in Dr. Benson’s expert report. (See Exs. A, C.) Dr. Platt stresses three
points: (i) a link between vaccination and GBS has not been established (ii) the timing of
symptom onset is not biologically plausible and (iii) a more plausible trigger for GBS in
this case was petitioner’s streptococcal infection. (Ex. C, p. 4.) To the first point, Dr.
Platt highlights the conclusions from Haber et al. (2009), an oft-cited study in this
Program. (Id. at 5.) Haber et al. concluded that the evidence for causal association to
GBS is strongest for the swine influenza vaccine that was used in 1976-77, though
studies of influenza vaccines used in subsequent years, “have found small or no
increased risk of GBS.” (Id. (quoting Penina Haber et al., Vaccines and Guillain-Barre
Syndrome, 32 DRUG SAFETY 309 (2009) (Ex. F)).) Haber et al. also found no correlation
between oral polio vaccine or tetanus -toxoid-containing vaccines and GBS (despite the
earlier IOM report). (Id.; see also 2012 IOM Report, supra, at Ex. E.) To the second
point, Dr. Platt stresses that in the only case report cited by Dr. Shafrir where
neurological symptoms started the day after vaccination, the authors themselves did not
find it likely that GBS was vaccine-caused. (Ex. C, p. 7 (citing Schessl et al., supra, at
Ex. 24).) In that patient with a one-day onset, the authors note that the onset was “too

26
   Dr. Platt is a clinical immunologist with board certification in Allergy and Clinical Immunology working at
Boston Children’s Hospital. (Ex. D.) He earned his M.D. and Ph.D. in Immunobiology from the Yale
School of Medicine. (Id.) His clinical expertise is in the diagnosis and treatment of allergic and
immunologic diseases. (Ex. C, p. 1.) In his practice, he evaluates and treats patients with a broad range
of immune-mediated diseases including autoimmune, hypersensitivity and immunodeficiency disorders.
(Id.) He frequently treats patients with various reactions to drugs and vaccines. (Id.) His Ph.D. research
was on the cellular biology of dendritic cells, which are required for the initiation of adaptive immune
responses. He has co-authored over twenty peer reviewed articles and three book chapters. (Id.)

                                                      27
short to warrant a causal relationship.” 27 (Schessl et al., supra, at Ex. 24, p. 610.)
Finally, Dr. Platt opines that petitioner’s streptococcal infection was a more plausible
trigger for GBS. (Ex. C, pp. 8-10 (citing Nobuhiro Yuki & Koichi Hirata, Fisher’s
Syndrome and Group A Streptococcal Infection, 160 J. NEURO. SCI. 64 (1998) (Ex. M)).)
While not a common trigger for GBS, Dr. Platt indicates that infection has at least two
features that vaccines do not, making it a more likely trigger: (1) a precedent for causing
immune mediated disorders such as acute rheumatic fever and acute
glomerulonephritis and (2) the features of pathogen replication, epitope spreading and
antigen persistence that vaccines lack. (Ex. C, p. 10.)

        In his second report, Dr. Platt agrees that protein sequence homology is not the
only theory of molecular mimicry capable of demonstrating cross-reactivity. (Ex. RR, p.
3.) However, Dr. Platt disagrees that direct evidence supports a causal link between
GBS and tetanus toxoid. (Id. at 4.) He stresses that the Inic-Kanada et al. study found
that certain subpopulations of antibodies raised against tetanus toxoid in mice are
cross-reactive with b2GPI. (Id. at 5 (citing Inic-Kanada et al., supra, at Ex. 111).) Dr.
Platt responds, “[t]he development of such autoantibodies could theoretically induce a
disorder call antiphospholipid syndrome, a clotting disorder, which is not relevant in this
case.” (Ex. RR, p. 6.) Next, Dr. Platt explains that Dolimbek et al. studied sera from
nine individuals who had been vaccinated with tetanus vaccines for antibodies that
bound to botulism toxoid as well. (Id. (citing Dolimbek et al., supra, at Ex. 112).) These
results, according to Dr. Platt, show that antibodies against tetanus toxoid antibodies
cross-react with botulinum neurotoxins—which does not demonstrate an association
between tetanus toxoid immunization and risk of autoimmunity. (Id.) Kursula does not
mention tetanus toxoid or vaccination in the article—instead the article focuses on
structural properties of proteins within the myelin sheath. (Id. (citing Kursula, supra, at
Ex. 113).)

       Dr. Platt contends that there are no references showing that ILLs are tied to GBS
pathogenesis. (Ex. RR, p. 4.) He acknowledges that the timeline between vaccination
and disease onset is “theoretically possible by invoking innate immune cells, [but] there
is no evidence provided that these cells are actually involved in GBS pathogenesis, so
this remains an entirely theoretical model.” (Id. at 10.) Dr. Platt disagrees that the Van
Kaer article supports Dr. Akbari’s theory. Dr. Platt stresses that Van Kaer comments on
the role of ILLs in the pathogenesis of multiple sclerosis and experimental autoimmune
encephalitis, but “this does not address how GBS would emerge on such a rapid
timeframe.” (Id.) He opines that there is no evidence for a model where ILLs could
speed up the development of an adaptive immune response, or that molecular mimicry
can occur more quickly due to the presence of innate like lymphocytes. (Id.)

       In his final expert report, Dr. Platt accepts the premise that gamma delta T cells
may play a role in the molecular mimicry response that has been established between
C. jejuni and GBS. (Ex. UU, p. 4.) However, he opines that “it is not reasonable to infer
from this that [gamma delta] T cells must therefore be driving GBS in response to

27
  That particular patient also suffered a concomitant upper respiratory infection. (Schessl et al., supra, at
Ex. 24.)

                                                     28
tetanus vaccination.” (Id.) Dr. Platt suggests that the reason Dr. Akbari invokes gamma
delta T cells is to explain how a reaction to the tetanus vaccine could happen within one
day of vaccination. (Id.) Yet, Dr. Platt recalls that C. jejuni infection typically occurs 1-4
weeks prior to GBS symptom onset. (Id.) In response to the theory involving ILCs, Dr.
Platt likewise stresses that there is no reference to vaccination in any of the literature
cited by Dr. Akbari. (Ex. UU, p. 4.) By focusing on the link between C. jejuni and GBS
rather than on the proposed link between tetanus toxoid and GBS, Dr. Platt argues that
petitioner’s expert misses the mark. (Id.)

       In regard to onset, Dr. Platt emphasizes that all of the studies cited by Dr. Akbari
reference the influenza vaccine – not Tdap or Menactra. (Ex. UU, p. 5.) He also
highlights the fact that the influenza vaccine is typically administered during fall and
winter months when there is increased incidence of respiratory illnesses (that are
associated with GBS). (Id.) Dr. Platt maintains that a number of well-performed studies
suggest there is no link between GBS and influenza vaccine. (Id.)

   VII.   Analysis

          a. Althen Prong One

        Under Althen prong one, petitioners must provide a “reputable medical theory,”
demonstrating that the vaccine received can cause the type of injury alleged. Pafford,
451 F.3d at 1355–56 (citations omitted). To satisfy this prong, petitioner's theory must
be based on a “sound and reliable medical or scientific explanation.” Knudsen v. Sec’y
of Health & Human Servs., 35 F.3d 543, 548 (Fed. Cir. 1994). Such a theory must only
be “legally probable, not medically or scientifically certain.” Id. at 549. Petitioners may
satisfy the first Althen prong without resort to medical literature, epidemiological studies,
demonstration of a specific mechanism, or a generally accepted medical theory.
Andreu v. Sec’y of Health & Human Servs., 569 F.3d 1367, 1378-79 (Fed. Cir. 2009)
(citing Capizzano v. Sec’y of Health & Human Servs., 440 F.3d 1317, 1325-26 (Fed. Cir.
2006)). Scientific evidence offered to establish Althen prong one is viewed “not through
the lens of the laboratorian, but instead from the vantage point of the Vaccine Act's
preponderant evidence standard.” Id. at 1380. Nonetheless, although petitioners
cannot be required to show “epidemiologic studies, rechallenge, the presence of
pathological markers or genetic disposition, or general acceptance in the scientific or
medical communities to establish a logical sequence of cause and effect” (Capizzano,
440 F.3d at 1325), the special master may consider and evaluate such evidence when
filed. Andreu, 569 F.3d at 1379 (Special masters may consider medical literature and
epidemiological evidence, when it is submitted, in “reaching an informed judgment as to
whether a particular vaccine likely caused a particular injury.”).

       Based on this standard, and upon review of the record as a whole, I conclude
that petitioner has met his preponderant burden of proof with respect to Althen prong
one for the reasons discussed below. Specifically, I find that there is adequate
evidence of record to demonstrate that Tdap vaccines can cause GBS. Petitioner’s

                                             29
experts offer further information regarding the ability of the Menactra vaccine to also
cause GBS. However, it is unnecessary to reach those points to resolve this case.

                      i. Vaccine-Caused GBS Is Biologically Plausible

       Context is important in evaluating petitioner’s medical theory of causation in this
case. Before reaching the particulars of petitioner’s vaccine-specific theory, the
following points are all evidenced on this record and are beyond meaningful dispute:
GBS is an autoimmune condition. (Baxter et al., supra, at Ex. II, p. 1.) As an
autoimmune condition, GBS is generally accepted to have multiple infectious triggers.
(Id.; Ropper et al., supra, at Ex. 21.) Yet, among those triggers, only c. jejuni is
accepted as having a demonstrated molecular mimic. (Haber et al., supra, at Ex. F, p.
311.) Further to these points, GBS has also been epidemiologically associated with at
least two formulations of the influenza vaccine, a swine flu formulation from the 1970s
and an H1N1 formulation from 2009, and has also been linked to an older version of a
rabies vaccine. (1994 IOM Report, supra, at Ex. G; Haber et al., supra, at Ex. F.)

       Because petitioners in this program are allowed to prove their cases
circumstantially, and because experts in this program are permitted to engage in at
least some extrapolation, the fact that GBS is well accepted as an autoimmune
condition with a wide variety of suspected antigenic triggers, inclusive of antigens from
both infection and vaccination, provides meaningful evidence supporting petitioner’s
burden of proof with respect to Althen prong one. That is, even before addressing any
vaccine-specific evidence, this general understanding of GBS pathophysiology
constitutes a reasonably strong starting premise for a claim that vaccines beyond the flu
vaccine can be implicated as triggers of GBS.

        Respondent’s experts do not acknowledge the strength in this starting premise.
In particular, both of respondent’s experts contend that the evidence supporting
petitioner’s case cannot overcome the lack of epidemiologic support. 28 This suggests
that they are requiring a degree of scientific confirmation that exceeds what petitioner is
obligated to prove in this program and reduces the persuasive value of their competing
opinions. Petitioners are not obligated to prove their case epidemiologically. Moreover,
the IOM, which Dr. Platt in particular relies upon as persuasive, has consistently
explained that epidemiology alone is not dispositive.

28
  Dr. Benson writes that “[a]lthough long term, large scale data looking for vaccine associated
complications for both vaccines that [petitioner] received, Dr. Shafrir presents predominantly small scale,
basic science, old data and case reports to support his arguments.” (Ex. A, p. 5.) Dr. Benson charges
that Dr. Shafrir is engaged in speculation because “[a]lthough much basic science literature is cited . . . no
large scale human data is presented.” (Id. at 6.) Dr. Platt similarly contends that “[i]t is essential to
remember that given the millions of vaccinations administered each year, a number of patients who
develop GBS will have received vaccination in the preceding weeks by chance alone. Therefore, to
establish causality, case reports alone are not sufficient. Fortunately, careful analysis of the literature has
been performed giving epidemiological weight only to studies that make use of control groups.” (Ex. C, p.
5.) Dr. Platt contends that not even the link between the flu vaccine and GBS can be said to be “well
established” and therefore “there is in fact no consensus that vaccines induce GBS.” (Id. at 6-7.)

                                                      30
        In assessing potential adverse events of vaccines, the IOM has consistently used
a methodology that accepts a general background of biologic plausibility coupled with
more specific, but generally more limited, evidence relating to the specific combination
of vaccine and injury. This evidence may include epidemiology, but is not limited to
epidemiology. Two comprehensive IOM reports are in evidence in this case. The 1994
IOM report and the 2012 report. (1994 IOM Report, supra, at Ex. G; 2012 IOM Report,
supra, at Ex. E.) The 1994 report defines “evidence favor[ing] acceptance of a causal
relationship” as follows:

        The balance of evidence from one or more case reports or epidemiologic
        studies provides evidence for a causal relation that outweighs the evidence
        against such a relation. Demonstrated biologic plausibility was considered
        supportive of a decision to accept a causal relation but insufficient on its
        own to shift the balance of evidence from other sources.

(1994 IOM Report, supra, at Ex. G, p. 33 (emphasis added).) Similarly, the 2012 IOM
report reserved the category of “favors acceptance of a causal relationship” for those
cases that had “either epidemiologic evidence of moderate certainty of an increased risk
or by mechanistic evidence of intermediate weight.” (2012 IOM Report, supra, at Ex. E,
p. 18.) Mechanistic evidence of “intermediate weight” includes “[a]t least two cases,
taken together, for which the committee concludes the vaccine may be a contributing
cause of the adverse event, based on an overall assessment of attribution in the
available cases and clinical, diagnostic, or experimental evidence consistent with the
relevant biological response to vaccine.” (Id. at 14 (emphasis original).) 29

       Thus, while petitioner’s burden of proof is not limited to demonstrating biologic
plausibility, 30 the general background regarding the nature and causes of GBS is highly
relevant. Dr. Shafrir and Dr. Akbari both invoke this background as partial support for
their vaccine-specific causal opinions and, contrary to respondent’s experts’ view, that
reliance is sound and reliable. Dr. Akbari’s first report in particular provides extensive

29
  Applying these standards to the available evidence, the two IOM reports reached different conclusions
with the respect to whether tetanus-containing vaccines can cause GBS. (Compare 1994 IOM Report,
supra, at Ex. G; and 2012 IOM Report, supra, at Ex. E.) This difference is discussed separately below.
30
   The Federal Circuit has “consistently rejected theories that the vaccine only ‘likely caused’ the injury
and reiterated that a ‘plausible’ or ‘possible’ causal theory does not satisfy the standard.” Boatmon, 941
F.3d at 1360. This is not to be confused with what is “biologically plausible,” which simply expresses that
the point being made is consistent with existing medical knowledge. E.g., Doe93 v. Sec’y of Health &
Human Servs., 98 Fed Cl. 553, 567 (2011) (collecting citations to cases where petitioners have been
required to present a “biologically plausible” theory as that term is understood in the scientific
community).); accord Kottenstette v. Sec’y of Health & Human Servs., 861 Fed. App’x 433, 440-41 (Fed.
Cir. 2021) (assigning error where the Court of Federal Claims interpreted the special master’s reference
to “biologic credibility” as equivalent to the type of merely “plausible” theory presented in Boatmon.) A
proposed theory must necessarily be biologically plausible (i.e., consistent with existing medical
knowledge) in order to be “sound and reliable;” however, biologic plausibility is not itself the legal
standard. Boatmon, 941 F.3d at 1359-60.

                                                    31
discussion of the immunology underlying GBS and autoimmunity more broadly that
provides a theoretical framework for petitioner’s Althen prong one showing.

                    ii. The 1994 IOM Report Provides Some Evidence to Support
                        Petitioner’s Claim and Is Not Automatically Outweighed by the 2012
                        Report

       Further to this general biologic plausibility, Dr. Shafrir stressed, among many
other points raised, that the prescribing information for Adacel Tdap vaccine at issue in
this case includes a warning of the potential risk of post-vaccination GBS among those
who previously suffered GBS. (Ex. 15, p. 32; Ex. 48, p. 4.) While these warnings are
not admissions and do not in themselves constitute proof of causation, it does raise the
question of whether it reflects a reasonable, ongoing concern. 31 The Adacel warning is
based on the above-referenced 1994 IOM report. (Ex. 48, pp. 4, 27.) The 1994 IOM
report concluded that “[t]he evidence favors a causal relation between tetanus toxoid
and GBS. If the evidence favors a casual relation between tetanus toxoid and GBS,
then in the committee’s judgment the evidence favors a casual relation between
vaccines containing tetanus toxoid (DT and Td) and GBS.” (1994 IOM Report, supra, at
Ex. G, p. 89.)

        Ordinarily, recognition of a causal relationship by the IOM would be strong
evidence favoring petitioner’s claim. However, respondent argues that this report is, in
effect, outdated. (ECF No. 76, p. 13.) In fact, respondent contends that to cite to an
older IOM report is “misleading,” because the prior IOM report has been “discredited”
and the IOM has issued a more recent report that represents the IOM’s current
position. 32 (Id.) Petitioner disagrees. (ECF No. 77, pp. 7-8.)

       Respondent’s argument is reasonable in at least the general sense that the
Vaccine Act envisions both that the Secretary will update the Vaccine Injury Table over
time and that the Secretary will rely on the IOM to study the risks of vaccines covered
by the program. § 300aa-2; § 300aa-5; § 300aa-14(c). In the ordinary course it can
31
  In some prior cases, special masters have concluded broadly that “[s]tatements contained in vaccine
package inserts do not constitute reliable proof of causation, and cannot be deemed admissions that the
vaccines in question have the capacity to harm a particular petitioner in a specific manner.” Sullivan v.
Sec'y of Health & Human Servs., No. 10-398V, 2015 WL 1404957, at *20 (Fed. Cl. Spec. Mstr. Feb. 13,
2015) (citing Werderitsh v. Sec'y of Health & Human Servs., No. 99-319V, 2005 WL 3320041, at *8 (Fed.
Cl. Spec. Mstr. Nov. 10, 2005); see also 21 C.F.R. § 600.80(l). It has also been observed, however, that
the fact that package inserts are not admissions does not prevent them from including information that
does have value, in particular information provided by the clinical trials described by the package insert.
Cottingham v. Sec’y of Health & Human Servs., 15-1291V, 2021 WL 347020, *23-26 (Fed. Cl. Spec. Mstr.
Jan. 7, 2021), vacated on other grounds, 154 Fed. Cl. 790 (2021).
32
  It should be noted that, although the Vaccine Act contemplates that the IOM’s review will be highly
relevant to the Secretary, the IOM’s conclusion is not coextensive with the position of the government.
For example, as discussed above, the special master in Mohamad discussed several other sources of
governmental statement under the authority of the Secretary of Health & Human Services that are not
consistent with the IOM’s 2012 conclusion. 2022 WL 711604. With regard to whether the package
warning is in itself outdated, see n. 22, supra.

                                                    32
generally be expected that a more up to date IOM review is likely to carry greater weight
in that it should better reflect current scientific understanding. Thus, prior decisions by
special masters have accepted the IOM’s 2012 conclusion on the same question at
issue here despite the existence of the prior report. Howard v. Sec’y of Health &
Human Servs., No. 16-1592V, 2022 WL 4869354, at *9 (Fed. Cl. Spec. Mstr. Aug. 31,
2022); Sanchez v. Sec’y of Health & Human Servs., No. 18-1012V, 2022 WL 1013264,
at *22 (Fed. Cl. Spec. Mstr. Mar. 11, 2022); Rupert v. Sec’y of Health & Human Servs.,
No. 10-160V, 2014 WL 785256, at *7 (Fed. Cl. Spec. Mstr. Feb. 3, 2014). However,
nothing in the Vaccine Act suggests that the 2012 report automatically controls. The
1994 and 2012 reports represent two independent reviews by two different committees
and the 2012 report does not contain any explicit critique of the prior committee’s
work. 33 Both reports are in evidence in this case and the Vaccine Act does not dictate
that a special master is bound by the conclusions of any particular IOM report. Indeed,
as discussed above (see Section II), special masters may view the IOM as applying a
standard for causation that exceeds what petitioners are obligated to prove and
therefore do not treat the IOM’s conclusions as dispositive. Thus, the substance of both
reports should be weighed to assess their persuasive value rather than reflexively
accepting the latest report to the exclusion of the earlier report. Accord Mohamad, 2022
WL 711604, at *9-18 (considering the 1994 IOM report among many other pieces of
evidence and explaining that “the IOM’s 2012 report did change its previous
assessment, but not as drastically as sometimes suggested” and that “[w]hile
[respondent’s expert] is correct that the 2012 IOM report did not accept the theory that a
tetanus vaccine can cause GBS, the IOM report also did not reject the proposition
entirely”).

       In assessing the relationship between vaccination and GBS, the 1994 report
included a lengthy discussion of the pathophysiology of demyelinating disorders
broadly, and GBS specifically, accompanied by discussion of evidence linking GBS to
both the swine flu vaccine and rabies vaccine. (1994 IOM Report, supra, at Ex. G, pp.
39-47.) The IOM concluded that “it is biologically plausible that injection of an
inactivated virus, bacterium, or live attenuated virus might induce in the susceptible host
an autoimmune response by deregulation of the immune response, by non-specific
activation of the T cells directed against myelin proteins, or by autoimmunity triggered
by sequence similarities of proteins in the vaccine to host proteins such as those of
myelin.” (Id. at 48, 87.) Although the 2012 report stops short of issuing any similar
statement, it does not include any discussion that would refute the 1994 report’s
foundational understanding. (2012 IOM Report, supra, at Ex. E, pp. 71-73.) Much of
the 2012 report’s discussion of causal mechanisms confirms the same general

33
   A review of the committee assignments confirms that not a single member of the 1994 committee
participated in the 2012 review. (Compare 1994 IOM Report, supra, at Ex. G, pp. 5-6, and, 2012 IOM
Report, supra, at Ex. E, pp. 7-8.) The 1994 report is the result of the initial mandate included in the
Vaccine Act that the IOM conduct a broad review of possible adverse events associated with vaccines
commonly given in childhood. The 2012 study was the 12th time the IOM had conducted some review for
this program, though it was the first comprehensive review since the original 1994 report. (2012 IOM
Report, supra, at Ex. E, p. 11.) However, the 2012 report does not identify any specific prompt that
caused the Secretary to request the convening of the 2012 committee. (2012 IOM Report, supra, at Ex.
E, p. 32.)

                                                  33
principles of immunology. Similarly, but without extending to vaccination, the 2012
report stated in its weighing of mechanistic evidence that “[a]utoantibodies, complement
activation, immune complexes, T cells, and molecular mimicry may contribute to the
symptoms of GBS.” (2012 IOM Report, supra, at Ex. E, p. 558.)

         The 2012 report likewise did not identify any new evidence that refutes the older
report or renders it out of date regarding the specific conclusion that tetanus-containing
vaccines likely can cause GBS. The 2012 report identified four epidemiologic studies
for its review of the topic that post-dated the 1994 report; however, the report concluded
that all four studies had flaws that prevented them from contributing to the weight of
epidemiologic evidence. (2012 IOM Report, supra, at Ex. E, p. 557.) Thus, the
committee assessed the epidemiologic evidence as “insufficient or absent” to assess a
causal link between GBS and Tdap vaccines. Therefore, it is not the case that any new
epidemiology cast any doubt on the conclusion of the 1994 committee. The 2012 report
also identified five publications of case reports post-dating the 1994 report. (2012 IOM
Report, supra, at Ex. E, p. 557.) However, because case reports are by their very
nature anecdotal, the existence of later, unpersuasive case reports does not call into
question the conclusion of the 1994 report.

        Thus, Dr. Platt’s specific assertion that the 1994 report was “discredited” by later
studies is unpersuasive. For this point, Dr. Platt cites to Haber et al., a 2009 paper that
reviewed data related to GBS through 2008. (Ex. C, p. 6 (discussing Ex. F).) Dr. Platt
quotes Haber as stating that the 1994 IOM conclusion that the evidence favors a
relationship between GBS and tetanus-containing vaccines has been disproven by large
scale epidemiologic studies that found no correlation. (Id.) He then goes on to buttress
this point by noting that the IOM’s 2012 report changed the IOM’s position on the
subject. (Id.) Unacknowledged by Dr. Platt, however, is that subsequent to the 2009
Haber review, the IOM in that very 2012 report concluded that there is insufficient
epidemiology to assess the causal relationship at issue. (2012 IOM Report, supra, at
Ex. E, p. 557.) Dr. Benson similarly relies on epidemiology that the IOM specifically
rejected. (Compare Ex. A, p. 7 (citing Tuttle et al. (Ex. KK) in support of the assertion
that the lack of an epidemiologic association is “clear”)) with 2012 IOM Report, supra, at
Ex. E, p. 557 (concluding that Tuttle et al., does not contribute to the weight of
epidemiologic evidence).) Moreover, the 1994 IOM report’s conclusion was not primarily
an epidemiologic observation, and both the 1994 and 2012 IOM reports allow for
mechanistic evidence to outweigh epidemiologic evidence.

        Further to its foundational understanding of vaccine-caused demyelination, the
1994 report examined 29 prior cases of post-tetanus vaccine GBS, but found only three
that were described in enough detail to be accepted as true post-vaccination cases of
GBS. (1994 IOM Report, supra, at Ex. G, p. 87.) These were Hopf, 1980; Newton and
Janati, 1987; and Pollard and Selby, 1978. Of those, the committee found the Pollard
and Selby case report the most relevant. (Id.) However, the committee specified that
all three case reports documented GBS occurring “within an appropriate latency” of
between five days and six weeks. (Id.) The Pollard and Selby case report was
considered the most noteworthy because the subject “received the tetanus toxoid on

                                            34
three separate occasions over a period of 13 years, and following each vaccination a
self-limited episode of clear-cut, well-documented polyneuropathy of the GBS variety
ensued.” (Id. at 87.)

        Examining the 2012 report, the first difference of note is that the 2012 report
shifted the examination of the Pollard and Selby case report to a discussion of CIDP
rather than examining it as evidence relating to GBS. (2012 IOM Report, supra, at Ex.
E, p. 559.) However, it does not necessarily appear that this change alone explains the
difference in conclusion. 34 Apart from Pollard and Selby, the 2012 report examined a
total of ten case reports under its assessment of mechanistic evidence for GBS. (2012
IOM Report, supra, at Ex. E, pp. 557-58.) This included the Hopf and Newton and
Janati case reports previously considered by the 1994 report. (Id.) However, the 2012
report concludes that none of the case reports contributed to the weight of mechanistic
evidence. (Id. at 558.) String citing all ten of the case report publications, it indicates
that the reports “did not provide evidence beyond temporality” and that “[l]ong latencies
between vaccine administration and development of symptoms make it impossible to
rule out other possible causes.” (Id.) This is the limit of any criticism of either the Hopf
or Newton and Janati case reports in the 2012 report, though the prior 1994 report had
previously adjudged these care reports to be post-vaccination GBS and confirmed the
appropriateness of the latencies in each case.

       Thus, the difference in view between the 1994 and 2012 IOM reports turns
largely on a very narrow weighing of three case reports rather than on the availability of
any substantial new evidence. And, as the 2012 report explained, such weighing
involves “elements of expert clinical and scientific judgment.” (2012 IOM Report, supra,
at Ex. E, p. 24.) That is, the IOM effectively acknowledges in many cases there will not
be a clearly or self-evidently correct interpretation.

       In any event, the actual conclusion of the 2012 IOM report is that the evidence is
“inadequate to either accept or reject a causal relationship” between tetanus-containing
vaccines and GBS, which should not be confused with a conclusion that the evidence
favors rejection of a causal relationship. (2012 IOM Report, supra, at Ex. E, pp. 15,

34
   The 2012 IOM report separately defines GBS and CIDP respectively as acute and chronic immune-
related disorders of the peripheral nerves. (2012 IOM Report, supra, at Ex. E, pp. 637, 639.) However,
while the 1994 report did discuss GBS specifically, it premised its discussion on the biological plausibility
of vaccine-caused demyelinating disorders generally and did not include any separate discussion of
CIDP. (1994 IOM Report, supra, at Ex. G, p. 88.) Moreover, the diagnostic criteria for GBS discussed in
the 1994 report considers either prolonged progression or relapse to be a clinical variant of GBS. (1994
IOM Report, supra, at Ex. G, p. 41.) Apart from Pollard and Selby, two other case reports referenced in
the 1994 report’s discussion of GBS (Reinstein et al., 1982; Quast et al., 1979) are discussed in the 2012
report’s discussion of CIDP. Two case reports (Quast et al., 1979; Pritchard, 2002) are included in the
2012 reports’ discussions of both CIDP and GBS. (2012 IOM Report, supra, at Ex. E, pp. 557-59.)
Moreover, the 2012 report cites the same mechanistic language for both GBS and CIDP (i.e., that
autoantibodies, T cells, and molecular mimicry may explain the symptoms of CIDP). And, in any event,
given that the 2012 report concluded that none of the case reports addressed under either category, GBS
or CIDP, contributed to the weight of mechanistic evidence, reshuffling the case reports among the two
categories would not change the outcome.

                                                     35
558.) The IOM is very clear in explaining that “the committee began its assessment
from the position of neutrality; until all evidence was reviewed, it presumed neither
causation or lack of causation. The committee then moved from that position only when
the combination of epidemiologic evidence and mechanistic evidence suggest a more
definitive assessment regarding causation, either that the vaccines might or might not
pose an increased risk of adverse effect.” (Id. at 15.) The committee specifies that a
conclusion that there is inadequate evidence to accept or reject a causal relationship is
confirmation that the committee never “shift[ed] away from the neutral position.” (Id.)
Thus, petitioner is persuasive in contending that the IOM’s 2012 conclusion inherently
does not constitute any refutation of the earlier report. (ECF No. 77, p. 8.)

        In sum, the 1994 and 2012 reports represent two separate judgments by two
independent expert committees regarding much of the same basic underlying data. For
the reasons discussed above, respondent is not persuasive in suggesting that the
earlier report is either formally superseded or inherently outdated. Thus, the 1994
report, and its expert conclusion that there is evidence to favor a causal relationship
between tetanus-containing vaccines and GBS, does constitute some evidence
supportive of petitioner’s Althen prong one showing, albeit tempered by the fact that this
conclusion has not been consistently stated by the IOM.

                 iii. Petitioner’s Experts Are Persuasive in Opining that the Tdap
                      Vaccine Can Cause GBS

       Finally, the remaining question is whether petitioner’s experts are persuasive in
building upon all of the above to further assert that the Tdap vaccine at issue in this
case can cause GBS. On that question, petitioner’s experts rely on the following
additional points that I find persuasive when considered in light of the above-discussed
background:

          •   According to the IOM, “the effects of natural infection [represents] one
              type, albeit minor, of clinical or biological evidence in support of
              mechanisms.” (2012 IOM Report, supra, at Ex. E, p. 13.) In that regard,
              the IOM explains that diphtheria infection can lead to neuropathy in up to
              75% of severe infections and tetanus infection can likewise lead to
              neurologic damage. (2012 IOM Report, supra, at Ex. E, pp. 526, 528.)
              Further to this, Dr.Shafrir has highlighted literature showing that tetanus
              infection can cause peripheral neuritis generally and that GBS in particular
              has been documented as a complication of tetanus infection. (Ex. 15, p.
              34 (citing Shahani et al., supra, at Ex. 38; Lee et al., supra, at Ex. 39).)
              This is comparable to the logic Dr. Platt applies in preferring streptococcal
              infection as a cause of GBS. (Compare Shahani et al., supra, at Ex. 38,
              Lee et al., supra, at Ex. 39, and Yuki & Hirata, supra, at Ex. M.)

          •   A number of individual case reports specifically implicate vaccines
              containing tetanus and diphtheria in GBS. (Ex. 15, p. 33 (citing Exs. 28-
              33).) This includes the Newton and Janati and Pollard and Selby case

                                            36
                reports (Exs. 31, 33) reviewed by both of the above-discussed IOM
                reports as well as the Baust, Pritchard, and Bakshi and Graves case
                reports (Exs. 29, 32, 34) considered by the 2012 IOM report only. Dr.
                Shafrir additionally cites four cases of GBS from Thailand following dT
                vaccine reported in 2014 and an additional 2011 report of GBS following
                Tdap vaccine. (Exs. 28, 30.) Drs. Benson and Platt both reject the value
                of case reports categorically without offering any specific critique of the
                case reports filed in this case. (Ex. A, pp. 5 (Dr. Benson criticizing Dr.
                Shafrir for relying on “predominantly small scale, basic science” in lieu of
                epidemiology); Ex. C, p. 6 (Dr. Platt indicating that “to establish causality,
                case reports alone are not sufficient” and turning to epidemiology).) This
                is unpersuasive. Although case reports are of variable quality and context
                is significant, both the IOM and program caselaw suggest that case
                reports can sometimes have value when coupled with other evidence and
                cannot be reflexively disregarded. 35 (1994 IOM Report, supra, at Ex. G;
                2012 IOM Report, supra, at Ex. E.) Moreover, the 1994 IOM committee
                found value in at least some of these reports. Dr. Platt’s summary
                dismissal of the case reports supporting vaccine causation is especially
                unpersuasive because he himself otherwise affirmatively relies on case
                reports in the absence of epidemiology to assert strep infection as a cause
                of GBS. (Ex. C, p. 10 (citing Ex. M).)

            •   While Dr. Benson criticizes Dr. Shafrir’s “basic science literature,” she also
                concedes that the Bavaro study demonstrates “some homology between
                diphtheria and myelin associated proteins, [though] no large scale human
                data is presented.” (Ex. A, p. 6; Simona Bavar et al., Pentapeptide
                Sharing Between Corynebacterium Diphtheria Toxin and the Human
                Neural Protein Network, 33 IMMUNOPHARMOL. & IMMUNOTOXICOL. 360 (Ex.
                51).)

            •   Several pieces of literature regarding management of inflammatory
                neuropathies express caution regarding exposures to tetanus-containing
                vaccines. (Ex. 15, p. 34 (citing Hadden & Hughes, supra, at Ex. 35, p. 5
                (explaining that “the risk of relapse following immunization after GBS or
                CIDP was low but not absent . . . [for CIDP] the use of tetanus toxoid
                causes particular concern.”)); Lu & Zhu, supra, at Ex. 46, p. 4 (stating that

35
  Case reports “‘do not purport to establish causation definitively, and this deficiency does indeed reduce
their evidentiary value’. . . [but] ‘the fact that case reports can by their nature only present indicia of
causation does not deprive them of all evidentiary weight.’” Paluck v. Sec’y of Health & Human Servs.,
104 Fed. Cl. 457, 475 (2012) (quoting Campbell v. Sec’y of Health & Human Servs., 97 Fed. Cl. 650, 668
(2011), aff’d, 786 F.3d 1373 (Fed. Cir. 2015)). Case reports often present a detailed report of symptoms,
signs, diagnosis, treatment, and follow-up care. Oftentimes petitioners in the Program will highlight the
usefulness of case reports in cases of novel, unusual or rare diseases. See Patton v. Sec’y of Health &
Human Servs., 157 Fed. Cl. 159, 166-67 (2021). But see Crutchfield v. Sec’y of Health & Human Servs.,
No. 09-39V, 2014 WL 1665227, at *19 (Fed. Cl. Spec. Mstr. Apr. 7, 2014) (“single case reports of
Disease X occurring after Factor Y . . . do not offer strong evidence that the temporal relationship is a
causal one—the temporal relationship could be pure random chance”), aff’d, 125 Fed. Cl. 251 (2014).

                                                    37
              “[t]he risk of GBS or CIDP relapse following immunization is low, except
              for a concern with tetanus toxoid”).) Thus, there is evidence that the
              relevant medical treatment community considers the potential causal
              relationship to constitute a genuine real-world concern for patients.

          b. Althen Prong Two

        The second Althen prong requires proof of a logical sequence of cause and
effect, usually supported by facts derived from a petitioner's medical records. Althen,
418 F.3d at 1278; Andreu, 569 F.3d at 1375-77; Capizzano, 440 F.3d at 1326; Grant v.
Sec’y of Health & Human Servs., 956 F.2d 1144, 1148 (Fed. Cir. 1992). In establishing
that a vaccine “did cause” injury, the opinions and views of the injured party's treating
physicians are entitled to some weight. Andreu, 569 F.3d at 1367; Capizzano, 440 F.3d
at 1326 (“medical records and medical opinion testimony are favored in vaccine cases,
as treating physicians are likely to be in the best position to determine whether a ‘logical
sequence of cause and effect show [s] that the vaccination was the reason for the
injury’”) (quoting Althen, 418 F.3d at 1280). Medical records are generally viewed as
particularly trustworthy evidence, since they are created contemporaneously with the
treatment of the patient. Cucuras v. Sec’y of Health & Human Servs., 993 F.2d 1525,
1528 (Fed. Cir. 1993).

        However, medical records and/or statements of a treating physician’s views do
not per se bind the special master to adopt the conclusions of such an individual, even if
they must be considered and carefully evaluated. See § 13(b)(1) (providing that “[a]ny
such diagnosis, conclusion, judgment, test result, report, or summary shall not be
binding on the special master or court”); Snyder v. Sec’y of Health & Human Servs., 88
Fed.Cl. 706, 746 n.67 (2009) (“there is nothing . . . that mandates that the testimony of a
treating physician is sacrosanct—that it must be accepted in its entirety and cannot be
rebutted”). As with expert testimony offered to establish a theory of causation, the
opinions or diagnoses of treating physicians are only as trustworthy as the
reasonableness of their suppositions or bases. The views of treating physicians should
also be weighed against other, contrary evidence also present in the record—including
conflicting opinions among such individuals. Hibbard v. Sec’y of Health & Human
Servs., 100 Fed. Cl. 742, 749 (2011) (not arbitrary or capricious for special master to
weigh competing treating physicians' conclusions against each other), aff'd, 698 F.3d
1355 (Fed. Cir. 2012); Caves v. Sec’y of Health & Human Servs., 100 Fed. Cl. 119, 136
(2011), aff’d, 463 Fed. App’x 932 (Fed. Cir. 2012); Veryzer v. Sec’y of Health & Human
Servs., No. 06-522V, 2011 WL 1935813, at *17 (Fed. Cl. Spec. Mstr. Apr. 29, 2011),
mot. for review den’d, 100 Fed. Cl. 344, 356 (2011), aff'd without opinion, 475 Fed.
App’x 765 (Fed. Cir. 2012).

      On the whole, petitioner’s treating physicians provide support throughout the
medical records in favor of a logical sequence of cause and effect between his July 8,
2015 vaccinations and his GBS. In the most contemporaneous record, on July 9, 2015,
Dr. Hernandez wrote “[r]eceived vaccine yesterday, left facial drooping and ting[l]ing
hands and feet . . . 11 [year old] male presents to the ED with mother [complaining of]

                                             38
left facial drooping onset today . . . Immunization reaction, initial encounter possible.”
(Ex. 4, pp. 5-8.) On July 11, 2015, Dr. Martinez assessed petitioner with “1. Pain in
hands and feet and feet paresthesias . . . 2. [Rule out] infectious process or side effect
secondary to vaccine.” (Ex. 4, pp. 85-88.) Then on July 11, 2015, Dr. Robert Reid
noted “[c]onsider requesting the pediatrician to report this as a potential adverse
response to vaccine (VAERS).” (Ex. 4, pp. 58-62.) Still on July 11, 2015, immunologist
Dr. Sigua wrote:

          He received the DTaP and meningococcal vaccines on 7/8/15 to his left
          arm, and later that day reported localized pain . . . Assessment . . . 11 [year
          old] male presenting with worsening paresthesias, weakness, and bilateral
          ptosis. These symptoms started within a day after he was administered both
          the DTaP and meningococcal vaccines. His MRI brain/spine and CSF
          studies thus far have been unrevealing. There is concern that these
          symptoms may be related to the recent vaccine administrations.

(Ex. 4, pp. 63-66.) The following day on July 12, 2015, Dr. Martinez “fe[lt] he has an
atypical case of GBS in view of symptoms and [history] of vaccine in spite of labs[.] 2.
[Rule out] infectious process or side effect secondary to vaccine.” (Ex. 4, pp. 96-100.)
On July 13, 2015, Dr. Penson submitted a VAERS report. (Ex. 9, pp. 1-2.)

        Notably, following the discovery of petitioner’s positive strep culture, his treating
physicians continued to relate his vaccinations to his GBS. On July 14, 2015, Dr. Adler
wrote, “11 [year old] male with atypical GBS likely related to vaccination and
opthalmoplegia requiring intubation today for neuromuscular resp[iratory] failure and
with autonomic instability and positive throat [culture] for strep pyogenes.” (Ex. 4, p.
123.) The following day, July 15, 2015, Dr. Adler noted, “Immunologic [workup]
neg[ative] to date. Suspect vaccine assoc[iated] GBS. Strep [culture] positive on throat
swab.” (Id. at 158.) Later, on July 23, 2015, Dr. Deeter noted, “Per immunology and
infectious disease, process is likely related to the Menactra vaccination[36] . . . Report
has been made to the vaccine adverse event system.” (Id. at 286.) Finally, in
petitioner’s discharge summary on July 27, 2015, Dr. Ford stated, “[Infectious Disease]:
Throat culture was (+) for Group A Strep and he received a course of Clindamycin (PCN
allergy). He completed a course of Doxycycline to cover for tick-born pathogens. Viral
and bacterial cultures including CSF were all negative. His case was reported as an
adverse reaction to Menactra.” 37 (Ex. 4, p. 43.)

      Respondent raises three concerns with respect to Althen prong two. First and
perhaps foremost, respondent contends that the timing of onset relative to vaccination is
too short to allow for a logical sequence of cause and effect supporting vaccine
causation. (ECF No. 76, p. 15.) This issue is addressed under Althen prong three
36
   This appears to be a misstatement insofar as I do not find where any of the infectious disease or
immunology specialists indicated any preference for the Menactra over the Adacel vaccine as causal.
The specialist notes consistently report both vaccines (Ex. 4, pp. 58-66) and both vaccines were
ultimately included in the VAERS submission (Ex. 9).
37
     Again, this is a misstatement insofar as the VAERS report includes both vaccines. (Ex. 9.)

                                                      39
below. Because petitioner has preponderantly satisfied Althen prong three, the
question of timing likewise presents no barrier to petitioner’s claim relative to Althen
prong two for all the same reasons.

        Second, respondent contends that, in any event, the above-discussed treating
physician statements are limited to recognizing the coincident timing between
vaccination and injury. (ECF No. 76, p. 6, n. 4.) Further to this, Dr. Benson suggested
the treating physicians were merely recording a parental concern of vaccine-causation
and that “[n]owhere do any of [petitioner’s] providers state that they personally attribute
his disease to vaccination.” (Ex. A, p. 8.) I do not agree with these characterizations.
In addition to all of the notations above and the VAERS report, following his initial
hospitalization, petitioner’s treating physicians specifically included a diagnosis of
“Guillain-Barre syndrome following vaccination” among his discharge diagnoses. (Ex. 4,
p. 42.) Moreover, the records reflect that petitioner had specialist consultations with
both immunology and infectious disease. These consultations took a history of
petitioner’s activities and health over the preceding months to consider a wide range of
potential etiologies. (Ex. 4, pp. 59, 67.) But in any event, even accepting respondent’s
premise, Dr. Shafrir’s expert neurology analysis provides an additional unambiguous
causal opinion.

        Third, respondent stresses that infectious agents “have a well-established link
with GBS supported by epidemiologic and mechanistic evidence.” (ECF No. 76, p. 15.)
In petitioner’s case, respondent contends that further infectious causes were not ruled
out—leaving open the possibility that a gastrointestinal or upper respiratory infection
(e.g., strep), could have caused petitioner’s GBS. (Id.) Respondent highlights a note
from July 17, 2015, where petitioner’s neurologist noted that petitioner had a strep
infection prior to the onset of GBS and questioned whether it could have triggered his
illness. (Id. (citing Ex. 4, p. 75).) Respondent also stresses that infections, unlike
vaccines, have been identified as causes of some immune-mediated disorders and
feature antigen persistence, epitope spreading, pathogen replication—making it “far
more likely that an infection triggered petitioner’s GBS.” (Id.)

         Among published case series, approximately two-thirds of all cases of GBS are
preceded by a gastrointestinal or respiratory infection within three months prior. (Baxter
et al., supra, at Ex. II; Ropper et al., supra, at Ex. 21.) Campylobacter jejuni,
cytomegalovirus (CMV), Epstein-Barr virus, and Mycoplasma pneumoniae are known
precipitants of GBS, with other infections occurring no more often in GBS than in
controls. (Ropper et al., supra, at Ex. 21.) However, Dr. Benson and Dr. Platt’s
opinions that they cannot rule out the possibility of an infectious cause is not strong
evidence. While Dr. Platt indicates that “[g]roup A strep infection has been reported as
a potential cause of Miller Fisher variant GBS,” he also acknowledges that it is “certainly
not a common trigger.” (Ex. C, p. 11.) And, while respondent relies heavily on the idea
that infections generally have characteristics that make them more likely causes of
GBS, the evidence implicating this type of infection is very limited. (See Yuki & Hirata,
supra, at Ex. M.) No other type of infection is evidenced as even potentially present.

                                             40
        Additionally, Dr. Platt references literature which suggests that “antecedent
infection is noted two to four weeks prior to the onset in most GBS.” (Ex. C, p. 11 (citing
Dimachkie & Barohn, supra, at Ex. S).) As discussed relative to Althen prong three
below, Dr. Platt repeatedly emphasizes that illness typically precedes GBS by between
one to four weeks. (Ex. C, p. 8; Ex. RR, p. 10; Ex. UU, p. 4.) Petitioner’s throat swab
sample was obtained on July 12, 2015, and subsequently cultured on July 14, 2015,
which showed moderate growth for group A strep (Streptococcus pyogenes). (Ex. 4, p.
576.) Dr. Platt argues that petitioner had strep infection prior to hospitalization. 38 (Ex.
C, p. 9.) However, it is unclear, from these records alone, when petitioner acquired the
streptococcus infection, as the only notation of a sore throat in the medical records was
reported on July 11, 2015, in the context of petitioner’s intubation. (See Ex. 4, p. 79.)
On July 8, 2015, the day petitioner received the vaccines in question, he had a well-
child visit where no complaints or symptoms of illness were noted. (Ex. 2, pp. 61-63.)
Moreover, the history provided during petitioner’s infectious disease consult indicated
that during the month prior to his GBS, petitioner had been camping and vacationing
with no mention of any illness. (Ex. 4, pp. 59, 67.) Accordingly, there is not
preponderant evidence establishing the infection to have occurred within a timeframe
that respondent’s experts would agree is medically reasonable to infer causation.

            c. Althen prong three

        The third Althen prong requires establishing a “proximate temporal relationship”
between the vaccination and the injury alleged. Althen, 418 F.3d at 1281. That term
has been equated to the phrase “medically-acceptable temporal relationship.” Id. A
petitioner must offer “preponderant proof that the onset of symptoms occurred within a
timeframe which, given the medical understanding of the disorder's etiology, it is
medically acceptable to infer causation.” Bazan v. Sec’y of Health & Human Servs.,
539 F.3d 1347, 1352 (Fed. Cir. 2008). The explanation for what is a medically
acceptable timeframe must also coincide with the theory of how the relevant vaccine
can cause an injury (Althen prong one’s requirement). Id. at 1352; Shapiro v. Sec’y of
Health & Human Servs., 101 Fed. Cl. 532, 542 (2011), recons. den’d after remand, 105
Fed. Cl. 353 (2012), aff’d mem., 503 Fed. App’x 952 (Fed. Cir. 2013); Koehn v. Sec’y of
Health & Human Servs., No. 11-355V, 2013 WL 3214877 (Fed. Cl. Spec. Mstr. May 30,
2013), mot. for review den’d (Fed. Cl. Dec. 3, 2013), aff'd, 773 F.3d 1239 (Fed. Cir.
2014). In this case, this analysis involves two disputed points. First, what actually was
the latency between vaccination and onset of GBS in this case? Second, can the
vaccine(s) at issue cause GBS in that amount of time?
        With regard to the first question, there is little debate between the parties as to
the first relevant symptoms. Both parties’ neurology experts agree that onset of
weakness and progressive neurologic decline began on July 10, two days post-
vaccination (Ex. 15, pp. 29, 35, Ex. A, p. 3), but both parties also identify numbness and
tingling (paresthesia) in petitioner’s hands and feet occurring the day prior as his first

38
  Dr. Platt relies on a single citation to a medical record from July 17 that indicates a possible prior strep
infection at some unspecified time “prior to this illness.” (Ex. C, pp. 9-10.)

                                                      41
symptoms of GBS (Ex. 15, p. 31; Ex. A, p. 5). I agree. 39 The parties differ, however,
regarding when on July 9 those first symptoms of numbness and tingling began. Based
on my review of the record as a whole, the evidence preponderates in favor of a finding
that onset of petitioner’s symptoms of numbness and tingling, and thereby his GBS,
occurred during the evening of July 9, 2015, a little more than 24 hours post-
vaccination.
        Dr. Benson opines for respondent that onset was less than 24 hours post-
vaccination based on later histories that placed onset of extremity tingling earlier in the
day on July 9. (Ex. A, pp. 2-3, 6 (citing Ex. 4-1, pp. 56, 43, 64, 73, 150).) However,
this earlier onset is not preponderantly established. These later histories are not
uniform in their details. 40 Thus, Dr. Benson acknowledges that petitioner’s course
during the afternoon of July 9 is “unclear” with “variable accounts” contained in the
records. (Id.) In contrast, the record of petitioner’s first ED encounter is very clear in
explaining that when petitioner first presented for symptoms of ptosis and numbness
and tingling, these symptoms arose for the first time when he awoke from his afternoon
nap that began at 4pm, about 24 hours post vaccination. 41 (Ex. 4, p. 5.) That record
explicitly explains that when petitioner was picked up from band camp on July 9, he
complained of post-injection arm pain for which his mother provided Ibuprofen. Then,
he “went to sleep and when he woke up, mom noticed his left eyelid appeared to be
‘drooping.’ He also [complained of] tingling and numbing sensation to his bilateral
fingertips extending to his wrists and as well his toes extending all over the [sic.] both
feet.” (Id.) Although later reports are variable and inconsistent regarding onset of these

39
   According to the literature, the most common initial symptom of GBS is acroparesthesia, tingling in the
hands and feet, particularly the fingers and toes, with little objective sensory loss. (Dimachkie & Barohn,
supra, at Ex. K, p. 3; see also Acroparesthesia, DORLAND’S MEDICAL DICTIONARY ONLINE,
https://www.dorlandsonline.com/dorland/definition?id=724&searchterm=acroparesthesia (last accessed
Feb. 17, 2023).) Although Dr. Shafir suggests that petitioner’s ptosis should not be viewed as part of his
GBS (Ex. 15, p. 29), it is not necessary to resolve this question as I find that petitioner concurrently
experienced onset of numbness and tingling. Accordingly, even discounting the possibility that the ptosis
was an early symptom of the GBS, that would not change the assessment of onset. Facial nerve
involvement occurs in up to 70% of GBS cases. (Dimachkie & Barohn, supra, at Ex. K, p. 3.) Although
petitioner first experienced soreness in the arm in which his vaccines were administered and had some
indications of fatigue, there is not preponderant evidence this was related to his GBS, with the arm
soreness especially likely to have been an unrelated vaccine reaction. (Ex. 15, p. 30; Ex. A, p. 5.)
40
   For example, one of these histories indicates that petitioner had tingling in his fingers and toes and
shooting pains when he left for band camp on July 9. (Ex. 4, p. 42.) Another indicates that the morning
of July 9 “he didn’t want to get up or talk,” but that his shooting pains began “at noon.” (Id. at 55.) A third
indicates onset of numbness and tingling developed at camp, but pain in the hands and feet is first
mention after his subsequent nap. (Id. at 63.) A fourth indicates that he experienced pain in his hands
that day, but makes no mention of numbness or tingling. (Id. at 72.) These same histories are also
inconsistent regarding the onset of ptosis. (Compare Ex. 4, p. 42 (ptosis noted upon being picked up from
camp) and p. 55 (onset of ptosis noted only to be on Thursday) and p. 63 (ptosis noted upon waking from
afternoon nap).
41
  Although an exact time of vaccination does not appear to be indicated in petitioner’s medical records,
the records of his July 8, 2015, primary care appointment indicate that his blood was drawn at 4:45 PM.
(Ex. 2, p. 63.)

                                                      42
complaints, the promptness with which petitioner’s parents sought emergency medical
care means that the initial history was recorded mere hours after they first became
aware of petitioner’s symptoms. 42 This is also consistent with the affidavit account
provided. (Ex. 13, p. 1.) Moreover, all of the other experts in the case apart from Dr.
Benson assessed onset as having occurred one full day after vaccination. (Ex. 15, p.
30 (Dr. Shafrir indicating onset is “late evening or the night of 7/09/2015”); Ex. 120, p. 5
(Dr. Akbari stating onset is “approximately 24 hours” post-vaccination); Ex. C, p. 7 (Dr.
Platt asserting that both ptosis and paresthesia were both documented “one day
(approximately 24 hours) after vaccination”).)
         The next question is whether a one-day period of onset is medically appropriate
to infer vaccine causation. On this question, all agree that the onset in this case would
be atypically rapid if the GBS were caused by the vaccinations at issue. However,
petitioner’s experts provide several reasons for concluding that the rapid onset should
still be considered medically appropriate. 43 Respondent’s experts, by contrast, focus
almost exclusively on what is typical rather than what is possible or medically
reasonable and neither clearly articulates what they consider to be a minimum latency,
making it more difficult to assess and accept their competing opinions. In particular, Dr.
Platt explains that “[e]ven if it were established that tetanus and/or meningococcal
vaccination could cause GBS, the timing of the symptoms further weakens any potential
link. The reason why vaccine causality is unlikely in this case (perhaps unintuitively to
those not familiar with this literature), is that the symptoms started the day after
vaccination. When an infectious trigger is identified, it is typically between 1 to 4 weeks
between this antecedent infection and onset of weakness.” (Ex. C, p. 8 (citing Jacobs,
et al., supra, at Ex. I (emphasis added)).) 44 Dr. Platt stresses this “typical” timeframe
repeatedly throughout all of his reports. (Ex. C, p. 8; Ex. RR, p. 10; Ex. UU, p. 4.)

42
   Petitioner first presented to the emergency department on July 9, 2015, at 10:37 PM with a chief
complaint of facial drooping along with numbness and tingling in his hands and feet. (Ex. 4, p. 5.) These
symptoms were first observed following a 4:00 PM nap on July 9, 2015. (Id.) Petitioner averred that the
nap lasted for three hours (Ex. 13, p. 2), which is likely consistent with petitioner’s 10:37 PM presentation
time. (Ex. 4, p. 5.)
43
   Because the 1994 IOM report was discussed extensively with regard to Althen prong one, I note in the
interest of completeness that the 1994 committee indicated that the minimum latency for GBS is 5 days.
(1994 IOM Report, supra, at Ex. G, p. 45.) However, there are several reasons why this is not dispositive.
First, the authors characterized this only as a “conservative estimate” rather than any confirmed latency
period. (Id.) Additionally, this specific estimate was premised on a delayed hypersensitivity mechanism.
(Id.) However, that is not the limit of what the report concluded was the biologically plausible as a
mechanism of vaccine-caused demyelination. (Id. at 48.) Further, this Althen prong three analysis also
discusses a substantial amount of additional literature discussed by petitioner’s experts that post-dates
the 1994 report.
44
  Dr. Platt’s reliance on Jacobs et al. is itself less persuasive insofar as the Jacobs study itself does not
address timing of onset nor include specific findings regarding timing. Dr. Platt’s reference derives from a
statement in the introduction that notes GBS to follow infection in two-thirds of cases and that among
such cases there is an “interval of 1 to 4 weeks between antecedent infection and onset of weakness.”
(Ex. I, p. 2.) However, this leaves fully one-third of cases unaddressed. Dr. Shafrir likewise
acknowledges that a majority – about 60% - of cases of GBS will fit this pattern. (Ex. 15, p. 32.)
Moreover, other evidence of record discussed below suggests that this statement is an oversimplification
and/or overgeneralization.

                                                     43
        Dr. Shafrir explains, however, that GBS “is not a uniform entity.” (Ex. 15, p. 30.)
He explains that it is a pathological process affecting the peripheral nerves via different
mechanisms. He indicates that GBS represents an autoimmune process whereby
different antibodies may variously affect the nodes of Ranvier, myelin, or nerve axons.
(Id. at 30-31.) Thus, when speaking of GBS as single entity, it reflects a variable clinical
course. (Id.) Additionally, both Dr. Shafrir and Akbari stressed the importance of
genetic susceptibility with respect the variety of presentations seen among GBS
patients. (Ex. 15, pp. 36-37; Ex. 65, pp. 13-14.) Initially, Dr. Shafrir specifically invoked
genetic susceptibility as a factor that may help explain the rapid onset in this case,
noting that the timing and intensity of antibody production is genetically controlled. (Ex.
15, p. 37.) Dr. Akbari later opined that “[h]ost susceptibility to the development of GBS
is arguably one of the most important factors in the development of GBS independent of
the initiating pathologic cause.” (Ex. 65, p. 13.) And, indeed, Dr. Platt confirmed his
agreement with this broader point, noting it to be “accurate.” (Ex. RR, p. 7.) Dr. Shafrir
acknowledges, as Dr. Platt stresses, that 60% of GBS cases are preceded by an
infection occurring weeks prior to onset (Ex. 15, p. 32); however, he also cites a number
of studies wherein GBS has been attributed to either illnesses or vaccinations that
occurred within days prior to onset, including some cases where onset of GBS was
within one day of the antecedent event. (Id. at 36.)

        For example, petitioner has filed one study by Takahashi et al. that showed that
among over one hundred GBS patients who experienced their condition following
confirmed c. jejuni infection (an acute gastrointestinal illness), onset of neurological
symptoms occurred from between one- and 24-days following onset of diarrhea, with a
median onset of ten days post-diarrhea onset. (Takahashi et al., supra, at Ex. 59, p. 4.)
This not only shows at least some cases of GBS to have occurred within one day of a
generally well-established and clinically confirmed antecedent, but also more generally
presents a data curve embracing a shorter onset period than what Dr. Platt suggests by
citing a one-to-four-week period as “typical.” (Id. at 3 (Fig. 5).) Similarly, another paper
filed by respondent examined six prior studies with regard to the timing of onset of the
Miller Fisher variant of GBS, finding that the mean time from preceding illness to onset
of GBS symptoms varied by study from between 3.5 and 10 days with an overall mean
of 8.1 days. (Masahiro Mori et al., Fisher Syndrome: Clinical Features,
Immunopathogenesis and Management, 12 EXPERT REV. NEUROTHERAPEUTICS 1, 5
(2012) (Ex. N) (Table 1).) For the mean latency to have been 3.5 days, at least some of
the cases involved must necessarily have had onsets shorter than 3.5 days.
Additionally, an overall mean of 8.1 days among all the studies suggests an earlier
“typical” onset than what Dr. Platt urges. This is repeated by another study filed by
respondent which indicated an onset range of 1 to 30 days with a median latency of 8
days. (Masahiro Mori et al., Clinical Features and Prognosis of Miller Fisher Syndrome,
56 NEUROLOGY 1, 1 (2001) (Ex. O).)

      Additionally, two more pieces of literature relate this earlier timeframe to
vaccinations. A 2013 study published in the American Journal of Epidemiology

                                             44
examined the risk of GBS following the 2009-2010 H1N1 influenza vaccination. 45
(Polakowski, supra, at Ex. 129.) That study looked at two post-vaccination risk periods,
a 1-42 risk period and a narrower 8-21 day period. Although the study found a higher
risk within the narrower period, the risk for the 1-42 day period remained statistically
elevated after excluding cases with preceding illnesses and adjusting for seasonality. 46
(Id. at 7 (Table 4).) A separate chart within the paper confirms this analysis of a
statistically significant 1-42 day risk period included cases occurring at one- and two-
days post-vaccination. (Id. at 6 (Fig. 2).) A 2017 paper examined the clinical
characteristics of GBS cases in Korea that had been compensated within Korea’s
vaccine injury compensation program. (Park, supra, at Ex. 58.) Among that population,
over 97% experienced onset within three weeks of vaccination and a majority
experienced onsets within two days of vaccination. Again, as with the above-discussed
study regarding c. jejuni infection, this complicates respondent’s reliance on a one-to-
four-week onset being “typical.” Particularly relevant to this case involving a minor
vaccinee, the study also found that subjects under 19 years of age experienced faster
and more severe courses of GBS. Whereas those over 20 years of age had an
interquartile range of onset from three to 15 days post-vaccination, those 19 and under
had an interquartile range of onset from only one to three days. (Id. at 3.)

        Dr. Platt does explicitly state in his fist report that in his opinion a latency of one
to two days is “implausible.” (Ex. C, p. 5.) However, the basis for that assertion is not
fully explained. Dr. Platt never explicitly describes any medically reasonable timeframe
to infer causation beyond the one-to-four-week period he repeatedly cites as merely
“typical.” Noting a statement from one of Dr. Shafrir’s citations, Dr. Benson indirectly
suggests a minimum latency of four days. (Ex. A, p. 6.) Both Drs. Platt and Benson
offer some reference to the relationship between adaptive immunity and autoimmune
injury as a reason for questioning the timing of onset in this case. However, without
more, respondent’s position as to timing is not adequately explained simply by
reference to adaptive immunity.

       The 2012 IOM report filed by respondent explains that adaptive immunity in
general requires a “lag phase” before an adaptive immune response develops that is
“classically” believed to be at least four days, but in the case of a repeat exposure may
be as little as one day. (2012 IOM Report, supra, at Ex. E, p. 88.) After the lag phase,
antibodies increase in a logarithmic phase over days until reaching a plateau. (Id.) In
this case, petitioner’s medical records confirm that petitioner had 5 prior vaccinations
containing tetanus, diphtheria, and acellular pertussis. (Ex. 1.) Therefore, while
commencement of an adaptive immune response is not equivalent to disease onset,
general principles of adaptive immunity do suggest that petitioner’s adaptive immune
response to his Tdap vaccine would have been underway on July 9 when his symptoms
began. This is a point stressed by Dr. Shafrir when he raised the issue of immunologic
45
   As explained above (see Section II, supra) the evidence supporting an association between the 2009
H1N1 influenza vaccine and GBS contributed to the addition of GBS to the Vaccine Injury Table. The
Secretary considered the evidence “compelling, reliable, and valid.” 2017 WL 202456, at *6295.
46
     This result existed for cases using confidence levels 1-3 of the Brighton criteria for diagnosing GBS.

                                                       45
memory to help explain the onset in this case. (Ex. 15, p. 36.) Thus, for example, Dr.
Shafrir also notes that the Vaccine Injury Table allows a minimum latency for post-
influenza vaccine GBS of 3 days. (Id. at 36.) Further still, he observes that where
tetanus-containing vaccines are at issue, the Vaccine Injury Table allows an even
shorter latency of 48 hours for immune-mediated injury to peripheral nerves in the form
of brachial neuritis. 47 (Id. at 33 (citing 42 U.S.C. 300aa-14).) Both of these Table
timeframes for peripheral nerve disorders are shorter than what either Dr. Benson or Dr.
Platt have acknowledged is possible. (Ex. A, pp. 6-7; Ex. C, pp. 7-8.) While more could
surely be said regarding the time needed for an adaptive immune response to develop
into an autoimmune injury, respondent’s experts have not substantiated any such points
on this record.

       Additionally, the IOM explains, as Dr. Shafrir likewise highlights in his report (Ex.
15, p. 36), that tetanus-containing vaccines are among a subset of vaccines for which
alum adjuvant “may directly activate cells of the innate immune system through its effect
on local inflammasome complexes leading to the release of inflammatory mediators and
enhancement of the immune response.” (2012 IOM Report, supra, at Ex. E, p. 59
(internal citation omitted).) The IOM further relates this to its discussion of latency,
indicating that cells “classically associated with the innate immune response” contribute
to the activation and amplification of the adaptive immune response. (Id. at 58.)
Further to this, Drs. Shafrir and Akbari opine that although it is ultimately an
autoimmune disorder involving adaptive immunity, onset and symptom presentation of
GBS in particular should not be viewed strictly in terms of the adaptive immune
response. Specifically, Dr. Shafrir explains that multiple articles indicate that the innate
immune system plays an important role in the pathogenesis of GBS, noting especially
that the AIDP form of GBS that petitioner had is considered more T cell dependent as
compared to the AMAN type of GBS that is considered more antibody dependent. (Ex.
15, p. 33.) Dr. Shafrir also stresses that petitioner’s initial presentation of a local
vaccine reaction (arm pain) and his early fatigue suggest he was experiencing a robust
innate immune reaction to his vaccination. (Id. at 30.)

       Dr. Akbari also explains that more recent literature describes a category of “fast
acting” innate like lymphocytes, which includes gamma delta T cells. According to Dr.
Akbari, gamma delta T cells have been seen in nerve biopsies of AIDP patients and
have the ability to directly promote molecular mimicry. (Ex. 120, p. 3.) Dr. Platt
responds that “[w]hile the timeline between vaccination and disease onset is
theoretically possible by invoking innate immune cells, there is no evidence provided

47
  The exact pathophysiological mechanism in brachial neuritis is unknown, but immune triggers are
suspected, as well as infection, mechanical factors, (repetitive or strenuous motor tasks), and individual
(genetic susceptibility. (JJ Jeroen et al., Neuralgic Amyotrophy: An Update on Diagnosis,
Pathophysiology, and Treatment, 53 MUSCLE NERVE 337 (2016) (Ex. 27).) Biopsies of patients with
brachial neuritis have shown epineural perivascular mononuclear T-cell infiltration and active multifocal
axonal degeneration without vessel wall inflammation or necrosis. (Id. at 340.) A further study reported a
decrease in peripheral blood CD81 T-suppressor cytotoxic lymphocytes in the acute phase, which is also
seen in GBS and facial nerve palsy. (Id.) Taken together, researchers suspect an immune-mediated
origin. (Id.)

                                                   46
that these cells are actually involved in GBS pathogenesis, so this remains an entirely
theoretical model.” (Ex. RR, p. 10.) However, Dr. Platt’s own citation indicates that
gamma delta T-cells “have been shown to play a central role in the pathogenesis of
GBS” and also that the gamma delta T-cells have also been shown to react to myelin
proteins. 48 (Manuel Rojas et al., Molecular Mimicry and Autoimmunity, 95 J.
AUTOIMMUNITY 100, 104 (2018) (Ex. L).)

         In light of the above, Drs. Shafrir and Akbari have provided seemingly reputable
bases for opining that onset of GBS within one day of vaccination can be viewed as
medically appropriate despite being atypical while respondent’s experts have failed to
refute that assertion on this record. Moreover, petitioner’s experts’ view is apparently
shared by petitioner’s treating physicians. Despite being aware of the rapid timing of
onset relative to vaccination, petitioner’s own treating physicians explicitly diagnosed
him with “Guillain-Barre syndrome following vaccination.” (Ex. 4, pp. 42, 125, 140.) It is
also difficult to separate respondent’s experts’ conclusions with respect to Althen prong
three from their conclusions regarding Althen prong one, which have already been
addressed above and found less persuasive. In his first report Dr. Platt quotes Dr.
Shafrir’s statement that “[i]mmunization is a well-known trigger for Guillain-Barre
syndrome and its variants.” (Ex. C, p. 5 (quoting Ex. 15, p. 32.) In response, he writes:
“If this were true, it would stand to reason that petitioner’s symptoms may simply be
atypical in that they began prior to the expected time window.” (Ex. C, p. 5.) Thus,
while he would still clearly find it irregular, it is far from clear that Dr. Platt would treat the
timing of onset in this case as dispositive if he were otherwise convinced that the
vaccine(s) at issue can in general cause GBS. 49

       While the petitioner in this case has preponderantly satisfied Althen prong three
despite an atypically rapid onset of just one day, this is a close call and the conclusion is
a function of the specific record in this case. The conclusion that a one-day onset is
medically appropriate for post-vaccination GBS is not unprecedented, but neither is it
the norm. Of the few GBS non-Table claims adjudicated in the Program where onset
occurred earlier than three days after vaccination most have not succeeded. 50 On a
48
  In his final report, Dr. Platt ultimately concedes that the literature does support a role for delta gamma
cells in the pathogenesis of GBS, but limits his acceptance of that premise to the specific context of
molecular mimicry following c. jejuni infection and reiterates his reliance on a “typical” onset period of
between one to four weeks between infection and onset of GBS. (Ex. UU, p. 4.)
49
   This point is further evidenced by Dr. Platt’s opinion with respect to an alternative cause. Dr. Platt
explains in his reports that he finds petitioner’s possible strep throat infection to be a more likely cause of
his GBS. (Ex. C, pp. 8-10; Ex. RR, p. 10; Ex. UU, p. 7.) However, as explained under Althen prong two,
above, petitioner’s medical records are inadequate to place the onset of his later discovered strep
infection. Despite a lack of any information regarding the purported latency, and despite acknowledging
that strep infection is “certainly not a common trigger” (Ex. C, p. 10), Dr. Platt finds it a more likely cause
because “[i]n contrast to vaccination, where there is negligible evidence of association with GBS, the link
between infection and GBS is well-established . . . . ” (Id. at 8). Dr. Platt makes no specific assertion that
petitioner’s strep infection occurred between one and four weeks prior to onset of his GBS or, indeed, that
the latency can even be determined.

 See Block v. Sec’y of Health & Human Servs., No. 19-969V, 2021 WL 5709764, at *4-5 (Fed. Cl. Spec.
50

Mstr. Oct. 29, 2021) (24-hour onset of GBS was not medically-acceptable where petitioner failed to

                                                      47
different record it is likely that I would reach a different conclusion. However, the
Federal Circuit holding in Paluck v. Secretary of Health & Human Services cautions
against setting “hard and fast deadline[s]” for onset. See 786 F.3d 1373, 1383-84 (Fed.
Cir. 2015) (stating that “[t]he special master further erred in setting a hard and fast
deadline” for onset and noting that the medical literature filed in the case “do not purport
to establish any definitive timeframe for onset of clinical symptoms.”). Moreover, “[t]he
Vaccine Act does not contemplate full blown tort litigation in the Court of Federal
Claims. The Vaccine Act established a federal ‘compensation program’ under which
awards are to be ‘made to vaccine-injured persons quickly, easily, and with certainty
and generosity.’” Knudsen, 35 F.3d at 549 (quoting H.R.Rep. No. 99–908, 99th Cong.,
2d Sess. 18, reprinted in 1986 U.S.C.C.A.N. 6344). Accordingly, the Federal Circuit has
suggested that this program represents a “system created by Congress, in which close
calls regarding causation are resolved in favor of injured claimants.” Althen, 418 F.3d at
1280.

            d. Factor Unrelated

        Based on the analysis above, petitioner has presented a prima facie case that
petitioner’s GBS was, more likely than not, caused by his Tdap vaccination by
demonstrating each of the three Althen prongs by preponderant evidence. Once
petitioner has satisfied his own burden pursuant under the Althen test, the burden shifts
to respondent to demonstrate that her injury was caused by factors unrelated to
vaccination. § 300aa-13(a)(1)(B); Deribeaux v. Sec’y of Health & Human Servs., 717
F.3d 1363, 1367 (Fed. Cir. 2013).

        In order to meet his burden, respondent must demonstrate by preponderant
evidence “that a particular agent or condition (or multiple agents/conditions) unrelated to
the vaccine was in fact the sole cause (thus excluding the vaccine as a substantial
factor).” de Bazan, 539 F.3d at 1354. As with petitioner’s burden under Althen,
respondent must show a logical sequence of cause and effect linking the injury to the
proposed factor unrelated. Deribeaux, 717 F.3d at 1369. It need not be scientifically
certain but must be legally probable. Id. Significantly, the Federal Circuit has rejected
the contention that the presence of a viral infection can per se be considered a factor

establish from an immunologic standpoint how GBS could being in such a short timeframe); Rowan v.
Sec’y of Health & Human Servs., No. 2020 WL 2954954, at *16-19 (36-hour post-vaccination onset of
GBS for elderly individual was not a medically-acceptable timeframe to support non-Table claim); Orton v.
Sec'y of Health & Human Servs., No. 13-631V, 2015 WL 1275459, at *3-4 (Fed. Cl. Spec. Mstr. Feb. 23,
2015) (one-day onset of GBS after flu vaccine administration not substantiated with expert opinion). Still,
in one other flu-GBS case the special master found that petitioner preponderantly demonstrated that a
24-hour onset post-vaccination was medically acceptable. Lehrman v. Sec’y of Health & Human Servs.,
No. 13-901, 2018 WL 1788477 at *16-19 (Fed. Cl. Spec. Mstr. Mar. 19, 2018). Petitioner’s expert
persuasively explained how his preceding upper respiratory infection acted synergistically with the
influenza vaccine, resulting in a rapid onset of GBS. Id. at *18. The expert explained that the petitioner’s
immune system was already activated due to the URI, while the flu vaccine was a subsequent immune
challenge which “boosted” the immune response. Id. While respondent’s expert in that case did not
opine that the flu vaccine was in any way associated with petitioner’s GBS, he agreed that, though rare,
GBS can occur within 24 hours—citing 2% of patients suffered onset of GBS between zero and one day
after vaccination in Schonberger’s study. Id.

                                                    48
unrelated to vaccination. Knudsen, 35 F.3d at 548-50. Rather, respondent bears a
burden of proving not only that there was a viral infection, but also that the infection was
principally responsible for causing petitioner’s injury. Id.

        Here, despite arguing that the inability to rule out infection complicates
petitioner’s showing under Althen prong two, respondent has not offered any argument
that the evidence of a step infection is adequate to meet his own burden of proof. (See
ECF No. 76.) In any event, I conclude respondent has not met his burden of proof for
the same reasons discussed within the Althen prongs two and three analysis above.

   VIII.   Conclusion

      Accordingly, for all the reasons described above, I find that petitioner is entitled to
compensation. Specifically, I find that petitioner has established by preponderant
evidence that petitioner’s GBS was caused-in-fact by his July 8, 2015 Tdap vaccination.
A separate damages order will be issued.

IT IS SO ORDERED.
                                                  s/Daniel T. Horner
                                                  Daniel T. Horner
                                                  Special Master

                                             49