Dennington v. Secretary of Health and Human Services

In the United States Court of Federal Claims
OFFICE OF SPECIAL MASTERS
No. 18-1303V
(to be published)

*************************
TARA DENNINGTON, *
* Chief Special Master Corcoran
*
Petitioner, * Filed: March 23, 2023
*
v. *
*
SECRETARY OF HEALTH *
AND HUMAN SERVICES, *
*
Respondent. *
*
*************************

Leah VaSahnja Durant, Law Offices of Leah V. Durant, PLLC, Washington, DC, for Petitioner.

Tyler King, U.S. Department of Justice, Washington, DC, for Respondent.

ENTITLEMENT DECISION 1

On August 28, 2018, Tara Dennington filed this action seeking compensation under the
National Vaccine Injury Compensation Program (the “Program”). 2 ECF No. 1. Petitioner alleges
that a tetanus, diphtheria, and acellular pertussis (“Tdap”) vaccine she received on August 30,
2015, caused her to incur Guillain-Barré syndrome (“GBS”). Id.

The parties have agreed that the matter could reasonably be resolved via ruling on the
record, and filed briefs in support of their respective positions. See Petitioner’s Motion, dated April

1
This Decision will be posted on the United States Court of Federal Claims’ website in accordance with the E-
Government Act of 2002, 44 U.S.C. § 3501 (2012). This means the Decision will be available to anyone with access
to the internet. As provided by 42 U.S.C. § 300aa-12(d)(4)(B), however, the parties may object to the published
Ruling’s inclusion of certain kinds of confidential information. Specifically, under Vaccine Rule 18(b), each party has
fourteen (14) days within which to request redaction “of any information furnished by that party: (1) that is a trade
secret or commercial or financial in substance and is privileged or confidential; or (2) that includes medical files or
similar files, the disclosure of which would constitute a clearly unwarranted invasion of privacy.” Vaccine Rule 18(b).
Otherwise, the entire Decision will be available to the public in its current form. Id.
2
The Vaccine Program comprises Part 2 of the National Childhood Vaccine Injury Act of 1986, Pub. L. No. 99-660,
100 Stat. 3758, codified as amended at 42 U.S.C. §§ 300aa-10 through 34 (2012) [hereinafter “Vaccine Act” or “the
Act”]. Individual section references hereafter will be to § 300aa of the Act (but will omit that statutory prefix).
22, 2022 (ECF No. 46) (“Mot.”); Respondent’s Opposition, dated July 7, 2022 (ECF No. 53)
(“Opp.”); Petitioner’s Reply, dated August 1, 2022 (ECF No. 55) (“Reply”). Having reviewed the
above plus the filed medical records, expert reports, and associated literature, I hereby deny an
entitlement award. As discussed in greater detail below, Petitioner has not preponderantly
established that the Tdap vaccine he received could cause GBS, or that it did so to her in a
medically-acceptable timeframe.

I. Fact History
Pre-Vaccination History and Previous GBS Diagnosis

Petitioner had a prior medical history of abdominal pain, allergic rhinitis, gastroesophageal
reflux disease, asthma, obsessive-compulsive disorder, anxiety, and irritable bowel syndrome. Ex.
12 at 7; Ex. 14 at 5–7. Significantly, she had previously suffered from GBS (Miller-Fisher variant)
in 2005, which left her with bilateral hearing loss, weakness and fatigue. Ex. 9 at 42.

Ms. Dennington’s earlier bout of GBS began approximately ten years earlier, in 2005,
when she was 15 years old. Records submitted from this period do not report any vaccine (let alone
a Tdap vaccination) being administered close-in-time to the illness, 3 and also indicate that a week
prior to visiting the emergency room, she had “developed a fever with a mild headache and neck
pain.” Ex. 16 at 20, 24–25; Ex. 22.

Petitioner eventually visited South Hermann emergency room and Texas Children’s
Hospital (“TCH”) in Houston, Texas, on August 21, 2005, for complaints of bilateral facial
paralysis, weakness, and ataxia, and was thereafter hospitalized until the end of that month. Ex. 16
at 20, 24–25. While hospitalized, a head CT scan and lumbar puncture were performed. Id. The
CT scan was reportedly normal and the lumbar puncture reportedly showed no white blood cells,
a protein level of 123, and normal glucose. Id. She complained of unsteadiness/dizziness with
lightheadedness that was worse when she sat or stood up. Id. A pediatric neurologist performed a
consultation the following day and expressed the suspicion that Petitioner was suffering from GBS
or possible spinal cord demyelination. Id. An MRI of the spine was normal, however, with no
evidence of demyelination. Ex. 16 at 23.

According to a progress note written on August 24, 2005, Petitioner was diagnosed with
GBS with bulbar involvement and transferred out of the pediatric intensive care unit to the

3
Petitioner filed a record titled “complete Vaccination Records,” but this record does not identify the source of its
information, the entity responsible for creating this record, or the basis for the information included in the chart. Ex.
22. This document indicates that Petitioner received Tdap vaccine doses several times in the several times in the years
before this illness. Id. But the dose administered closest in time to her first GBS diagnosis (in August 2005) occurred
15 months before, in 2004. Petitioner otherwise acknowledges that the record does not establish she received any Tdap
vaccine dose right before onset of her GBS symptoms at this prior time. Mot. at 28.

2
progressive care unit. 4 Ex. 16 at 25. After treatment with IVIG 5 she was to be transferred again for
continued rehabilitation. Id. at 25, 27. Petitioner underwent a rehabilitation evaluation at TCH on
August 26, 2005, and the record from it noted no cognitive impairment but difficulty with some
activities of daily living (“ADLs”) due to ataxia. Id. at 27. She also had impaired oral motor
function due to facial weakness but no gagging with oral intake. Id. She was scheduled for
physical, occupational, and speech therapy. 6 Id. at 28.

Petitioner saw neurologist Aloysia Schwabe, M.D., of Physical Medicine and
Rehabilitation Services at TCH, for follow-up on October 31, 2005. Ex. 16 at 37. Petitioner
reported persistent fatigue that affected her ability to participate in physical and occupational
therapy. Id. She continued occupational, physical, and speech therapy three times per week. Id.
She demonstrated improved strength and balance and was walking independently. Id. Petitioner
saw Dr. Schwabe again on January 9, 2006, complaining of persistent fatigue since October 2005.
Ex. 16 at 40–41. Her facial weakness persisted into the summer, although her overall motor
function had somewhat improved. Ex. 16 at 44–45. Otherwise, she received physical,
occupational, and speech therapy until she was discharged in April of 2006.

On November 16, 2006, Petitioner returned to TCH for a neurologic follow-up. Ex. 16 at
47. It was noted that she still suffered from a lack of energy and was fatigued easily, with some
lingering facial symptoms despite improvement. Id. Almost three years later, 7 on September 11,
2009, Petitioner had another neurology consultation at the Houston Neurological Institute, where
she was seen by neurologist Kathleen Eberle, M.D. Ex. 10 at 1. Dr. Eberle agreed that Petitioner’s
presentation was suggestive of the “Miller Fisher variant of [GBS] and/or Bickerstaff’s brainstem
encephalitis.” Id. An electromyogram (“EMG”) 8 performed on January 7, 2010, showed evidence

4
It was reported that prior to her presentation at TCH, Petitioner had a seven-day history of nasal congestion and
headache, and had been diagnosed by her primary care physician as sinusitis and sent home on antibiotic therapy. Ex.
16 at 25. When she developed facial drooping, Petitioner returned to the emergency room and was subsequently
transferred to TCH. Id.
5
Intravenous immunoglobulin (“IVIG”) is a blood product used to treat patients with antibody deficiencies, including
neurological disorders. Clinical Uses of Intravenous Immunoglobulin, NCBI (2005),
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1809480/ (last visited on Mar. 23, 2023).
6
Petitioner provided a letter from Neurodevelopmental Therapy Services (“NTS”) dated September 15, 2005,
indicating that Petitioner was admitted to their clinic on September 6, 2005 for occupational, physical, and speech
therapy. Ex. 21 at 1. NTS indicated that they no longer had records of the services provided as they had been destroyed
in accordance with the state of Texas rules for retention of such records. Id. at 2.
7
There are no records of care filed in this case for the timeframe between November 2006 and September 2009.
8
Electromyography is the process by which “an electrodiagnostic technique for recording the extracellular activity
(action potentials and evoked potentials) of skeletal muscles at rest, during voluntary contractions, and during
electrical stimulation; performed using any of a variety of surface electrodes, needle electrodes, and devices for
amplifying, transmitting, and recording the signals.” Electromyography, Dorland’s Medical Dictionary Online,
https://www.dorlandsonline.com/dorland/definition?id=15854&searchterm=electromyography (last visited Mar. 23,
2023).

3
of a “chronic sensorimotor neuropathy, predominantly demyelinating.” Id. at 5. That same month,
Dr. Eberle wrote a letter addressed “to whom it may concern” stating that Petitioner had been
diagnosed with a variant of GBS in 2005, and that she had “never achieved full recovery.” Ex. 19
at 1.

2015 Vaccination and GBS Treatment

On August 30, 2015, Petitioner (now 25 years old) was seen at the Kingwood Medical
Center emergency room (“Kingwood”) in Kingwood, Texas for a rash and abscess. Ex. 6 at 29.
Petitioner reported that she had scraped her foot on an old rusty pole and had mild pain, but no
fever, chills, or drainage from her wound. Id. She received the Tdap vaccine and was advised to
keep the wound clean and dry. Id. at 31; Ex. 1 at 1.

Two days later, on September 1, 2015, Petitioner returned to Kingwood with complaints
of numbness and tingling that was worse in her lower extremities. Ex. 6 at 11 (reporting that her
“foot just kinda feels asleep”). She denied chest pain and shortness of breath. Id. She also reported
receiving a tetanus vaccination two days earlier, and that she had a medical history of GBS. Id.
Physical examination did not document any abnormalities. Id. at 12–14. Approximately two hours
after arriving at Kingwood, Petitioner’s mother stated that Petitioner needed to see a neurologist,
and Petitioner and her mother left Kingwood “against medical advice.” Id. at 11–15.

Petitioner presented to TCH that same day. Ex. 8 at 3. She provided a history of numbness
of the left side of the face, leg, and toes. Id. Petitioner’s mother reported that Petitioner had been
seen at TCH in 2005 “with [the] same complaints after [she] received a [t]dap vaccination,” and
was then diagnosed with GBS (although the record as discussed does not indicate she received the
Tdap vaccine in 2005). Id. Petitioner also, however, reported a two-day history of a subjective
fever and nausea earlier in the day. Id. The attending resident noted that it was an “[i]nteresting
presentation of parasthesia and numbness which the patient states was very similar to onset of her
previous episode of [GBS].” Id. Upon examination, she had a normal respiratory exam and no
headaches or neck rigidity. Id. at 3–4. She had full bilateral upper and lower extremity strength
against resistance in all flexors and extensors, but decreased sensation in her left upper and lower
extremities and left face. Id. at 5.

Because Petitioner had transitioned to adult care, she was transferred to Houston Methodist
Hospital, where she was admitted on September 1, 2015, for complaints of weakness and
numbness in her legs for two days after receiving a Tdap vaccination. Ex. 7 at 136–37, Ex. 8 at 6.
Neurologist Robert Smith, M.D., evaluated Petitioner following her admission for possible GBS.
Id. at 140. Upon examination, Petitioner had mild right facial weakness. Id. at 141. Her motor
exam showed full strength in the right upper and lower extremities, but reduced strength in the left
upper and lower extremities. Id. The differential diagnosis included acute disseminated
encephalomyelitis and GBS, along with “possible nonorganic cause of weakness.” Id.

4
 A lumbar puncture done on September 2, 2015, revealed normal protein and glucose and
no oligoclonal bands. Ex. 7 at 302–03, 309. The brain MRI done that same day was also
unremarkable. Id. at 185. However, EMG/NCS testing yielded abnormal results, showing
decreased F-waves. Ex. 9 at 48–49. Dr. Smith initiated treatment with IVIG based on these results
and evidence of decreased reflexes. Ex. 7 at 146.

On September 4, 2015, a note in Petitioner’s neurology evaluation states that Ms.
Dennington had 4+/5 strength in the left upper and lower extremities with normal strength on the
right and a decreased 1+/4 reflex at the left knee, a normal 2+/4 reflex at the right knee, and absent
reflexes at the ankles bilaterally. Ex. 7 at 150. The note also indicated that Petitioner had mild
objective weakness and subjective numbness on the left side and because of her history of a
previous episode of the Miller-Fisher variant of GBS, there was concern about a recurrence and
she was to receive five doses of IVIG. Id.

Evolution of Treatment

Over the course of her treatment with IVIG, Petitioner reported that her symptoms were
improving. Ex. 7 at 151–52, 154. Petitioner was discharged home on September 6, 2015, after
completing five IVIG doses. Id. at 171, 369–70. Her discharge note included a “concern [] for a
possible recurrence of GBS.” Id. at 369–70.

Petitioner followed up with Dr. Smith on October 13, 2015, to evaluate her for chronic
inflammatory demyelinating polyradiculoneuropathy (“CIDP”). Ex. 9 at 39. Dr. Smith noted that
Petitioner was being seen for evaluation of “recurrent GBS vs CIDP, relapsing type after
hospitalization.” Id. He noted that Petitioner’s first episode of weakness occurred ten years prior
following a Tdap vaccination and “presumed viral infection with diarrhea/flulike [sic]
[symptoms].” Id. “Following repeat [Tdap in 2015] . . . [Petitioner] developed identical prodrome
of flu-like symptoms and diarrhea for several days followed by weakness.” Id. Dr. Smith also
noted that Petitioner had recovered from her earlier episode of GBS, “only for recurrent episode
with similar activating stimulus.” Id. He further noted the possibility of a diagnosis of CIDP, with
onset in 2015 with “exacerbation following similar activator.” Id.

Upon examination, Ms. Dennington displayed fatiguing nystagmus, abnormal facial
expression and weakness, decreased hearing to finger rub, decreased reflexes, and decreased
sensation to light touch in all extremities. Ex. 9 at 41. Dr. Smith assessed Petitioner with worsening
CIDP, noting that while Petitioner and her mother do not feel that she has worsened, she had
continued deficits and “slightly worsened proximal weakness” upon examination. Id. at 42. Her
reflexes had returned in the lower extremities, but remained suppressed in the upper extremities.
Id. Dr. Smith prescribed IVIG two days per month and referred Petitioner to physical therapy. Id.

5
 Petitioner underwent a physical therapy evaluation at Kindred Rehabilitation Hospital on
October 29, 2015. Ex. 2 at 4. She had nerve tingling in her face and muscle weakness. She wanted
to improve her balance and increase her endurance. Id. Petitioner participated in three additional
therapy sessions between November 5 and 12, 2015, and then “discharged herself due to the long
drive to therapy” on November 17, 2015. Id. at 9.

Petitioner followed up with Dr. Smith on December 10, 2015, for bilateral hearing loss,
CIDP, and mild memory loss. Ex. 9 at 35. She had begun IVIG treatment again, and noted that her
previous facial sensory dysesthesias had resolved, with improved limb endurance as well. Id.
However, she continued to have problems maintaining her posture and had problems with balance.
Id. Dr. Smith discussed a neuropsychology referral as Petitioner had “baseline deficits from
previous postvaccination event; though is fully functional.” Id. at 37. Dr. Smith also noted
“Description of Topics Counseled: Vestibular rehabilitation. When is GBS actually CIDP, and
when can therapy for chronic problem help repair in recurrent but inactive process. [Central
nervous system] involvement in post-vaccination [central and peripheral nervous system] injury.”
Id. at 37–38. Dr. Smith gave Petitioner a referral for physical and occupational therapy and ordered
an EMG/NCS. Id.

Petitioner saw Dr. Smith in a follow-up for recurrent GBS on March 16, 2016. Ex. 9 at 31.
Due to insurance reasons, Petitioner was not getting IVIG. Id. She was clinically stable but had
evidence of incomplete resolution of problems with limb posture and endurance. Id. Dr. Smith
noted that Ms. Dennington had a “mildly depressed affect” and on neurologic examination found
ongoing weakness in multiple muscles and muscle groups in the upper and lower extremities. Id.
at 33–34. His assessment was GBS, bilateral hearing loss (due to initial episode of GBS), and mild
memory disturbance from “post episode of post-vaccination GBS+ . . . with balance and memory
changes similar to those from previous episode 10 years earlier.” Id. at 34.

A repeat EMG/NCS on April 6, 2016, showed evidence of a “diffuse polyradiculopathy
with previous denervation and incomplete reinnervation.” Ex. 35 at 7–9. On May 25, 2016, Dr.
Smith noted that “for a variety of reasons” after November, Petitioner was no longer receiving
IVIG. Ex. 9 at 27. However, she had remained stable with slow improvement in strength and
endurance. Id.

In December 2016, Dr. Smith noted that Petitioner’s most recent EMG “documented no
new active lesions (not ongoing CIDP), but still showed evidence of distal demyelination - residual
yet to recover from her most recent episode of weakness.” Ex. 9 at 3. Dr. Smith noted persistent
deficits in fatigue, endurance, and focus, with milder deficits in weakness and sensory function.
Id. at 12. Dr. Smith indicated that he had written a letter documenting Petitioner’s deficits to be
used in her appeal to “government agencies involved in her oversight.” Id. Petitioner’s condition
and assessment at her May 2017 visit with Dr. Smith was essentially unchanged. Id. at 16–25.

6
 On May 25, 2018, Petitioner had a follow-up visit with Dr. Smith for evaluation of
recurrent GBS. Ex. 9 at 27–30. It noted that she was stable and slowly improving in strength and
duration over the past five months. Id. Physical examination showed weakness of the facial
muscles that was more pronounced on the right resulting in some asymmetry, ongoing weakness
of the extremities, and decreased to absent reflexes except at the knees. Id. Dr. Smith’s assessment
was GBS, though Petitioner “[i]nitially [had] some features suggestive of CIDP. . .” with lower
facial weakness due to recurrent GBS, and bilateral hearing loss after her initial episode of GBS.
Id. at 30.

The most recent visit with Dr. Smith in the records provided was on March 13, 2019. Ex.
20 at 18. Petitioner was no longer working (which had helped to reduce her anxiety level) and was
receiving Social Security disability compensation. Id. at 18–19.

II. Expert Reports
A. Petitioner’s Expert – Carlo Tornatore, M.D.

Dr. Tornatore, a board-certified neurologist, prepared two written reports for Petitioner in
support of the contention that the Tdap vaccine can cause GBS, and that it did so in this case.
Report, dated April 5, 2021, filed as Ex. 36 (ECF No. 38-1) (“Tornatore First Rep.”); Report, dated
January 10, 2022, filed as Ex. 38 (ECF No. 43-1) (“Tornatore Second Rep.”).

Dr. Tornatore graduated from Cornell University with a Bachelor of Arts in Neurobiology,
and attended Georgetown University Medical Center, where he received a Master of Science in
Physiology. Curriculum Vitae, filed as Ex. B on April 5, 2021 (ECF No. 42-21) (“Tornatore CV”)
at 2. He subsequently graduated from medical school at Georgetown University School of
Medicine, completing a residency in the Department of Neurology at Georgetown University
Hospital. Id. He also completed a fellowship in molecular virology at the National Institute of
Health in Bethesda, Maryland. Id. Dr. Tornatore has published multiple articles addressing cell
biology and pathology of demyelinating disorders. Id. at 8–16. Currently, he serves as Professor
and Chairman of the Department of Neurology at Georgetown University Medical Center,
Chairman and Neurologist-in-Chief of the Department of Neurology at Medstar Georgetown
University Hospital in Washington, D.C., and Executive Director of the Multiple Sclerosis Patient
Centered Specialty Home. Tornatore First Rep. at 1.

First Report

Dr. Tornatore opined that Petitioner has GBS, which he defined as an autoimmune
demyelinating neuropathy of the peripheral nervous system. Tornatore First Rep. at 21–22. It is
believed that foreign antigens (e.g., viral or bacterial infection or vaccination) result in activation

7
of the immune system—a normal mechanism to clear the offending antigen. Id. However, in rare
cases, the activation is misdirected, and both the humoral and cellular arms of the immune system
(the innate and adaptive responses, respectively) attack components of its own nervous system. Id.
In the case of GBS, the target of the immune response is the myelin (and in some cases the axons)
of the peripheral nervous system. Id. The resulting injury is manifested clinically by numbness and
weakness of the extremities, truncal muscles and muscles of the face and neck. Id. Unilateral or
bilateral facial weakness, as in Ms. Dennington’s situation, is very typical of GBS. Id.

Dr. Tornatore went into great detail discussing Ms. Dennington’s medical records in the
context of a GBS diagnosis (with this summation consisting of the majority of his first report).
Tornatore First Rep. at 2–20. He emphasized the fact that Petitioner had experienced two episodes
of GBS—thus, he deemed the best characterization of her diagnosis to be “recurrent GBS.” Id. at
21. Petitioner’s first episode began on August 21, 2005, with characteristics of facial diplegia and
motor weakness, and the second episode was on September 1, 2015, which occurred shortly after
receiving the Tdap vaccine (on August 30, 2015), and was marked with “nearly identical”
symptoms to the first episode. Id.; Ex. 6 at 11–15; Ex. 16 at 20. Petitioner’s EMG results from
September 2, 2015, indicated early acute proximal demyelination and normal cerebrospinal fluid
(“CSF”) protein levels, which was consistent with early GBS, according to Dr. Tornatore.
Tornatore First Rep. at 13–14, 21; Ex. 9 at 48–49; C. Fokke et al., Diagnosis of Guillain-Barré
Syndrome and Validation of Brighton Criteria, Brain 33, 41 (2014), filed as Ex. 50 (ECF No. 57-
1) (“Fokke”). And although one of Petitioner’s treaters (Dr. Smith) felt the 2015 GBS occurrence
had some characteristics of CIDP, Petitioner reached nadir within four weeks of onset—a defining
feature of GBS. Tornatore First Rep. at 21; Ex. 9 at 30, 39, 41.

Next, Dr. Tornatore explained how the Tdap vaccine could theoretically cause GBS.
Tornatore First Rep. at 22–24. The pathogenesis of GBS, Dr. Tornatore contended, is affected by
molecular mimicry post-exposure to viral or bacterial antigens (which in turn resemble or mimic,
host structures—meaning antibodies to the foreign antigens mistakenly attack the self). Id. at 22;
R. Hughes & D. Cornblath, Guillain-Barré Syndrome, 366 Lancet 1653, 1658 (2005), filed as Ex.
39 (ECF No. 47-1). The concept of molecular mimicry is well-established in immunology.
Tornatore First Rep. at 23; M. B. A. Oldstone, Molecular Mimicry, Microbial Infection, and
Autoimmune Disease: Evolution of the Concept, 296 Current Topics Microbiology & Immunology
1, 3, 13 (2005), filed as Ex. 40 (ECF No. 47-2); T. Komagamine & N. Yuki, Ganglioside Mimicry
as a Cause of Guillain-Barré Syndrome, 5 CNS & Neurological Disorders - Drug Targets 391,
395–96 (2006), filed as Ex. 52 (ECF No. 57-3) (discussing molecular mimicry in the context of
autoimmune neuropathies and Campylobacter jejuni).

Of relevance to the discussion of vaccinations, Dr. Tornatore noted that GBS has been
discussed in association with swine flu and tetanus vaccines. L. Schonberger et al., Guillain-Barré
Syndrome Following Vaccination in the National Influenza Immunization Program, United States,

8
1976–1977, 110 Am. J. Epidemiology 105, 120–22 (1979), filed as Ex. 42 (ECF No. 47-4)
(“Schonberger”). Additionally, other studies suggest that vaccines other than the flu vaccine can
be associated with GBS. N. Souayah et al., Guillain-Barre Syndrome After Vaccination in United
States: A Report from the CDC/FDA Vaccine Adverse Event Reporting System (1990–2005), 11
Neuromuscular Disease 1, 5 (2009), filed as Ex. 45 (ECF No. 47-7) (“[o]ur results suggest that
vaccines other than influenza vaccine can be associated with GBS.”). He also cites case reports of
autoimmune peripheral neuropathies following other vaccines. F. E. Shaw et al., Postmarketing
Surveillance for Neurologic Adverse Events Reported After Hepatitis B Vaccination, 127 Am. J.
Epidemiology 337, 344–50 (1988), filed as Ex. 44 (ECF No. 47-6) (“Shaw”); M. Khamaisi et al.,
Guillain-Barré Syndrome Following Hepatitis B Vaccination, 22 Clinical & Experimental
Rheumatology 767, 768–69 (2004), filed as Ex. 51 (ECF No. 57-2) (“Khamaisi”). Overall, due to
the recognized biological mechanisms discussed, Dr. Tornatore opined that the Tdap vaccine more
likely than not could result in autoimmune peripheral nerve demyelination clinically presenting as
GBS. Tornatore First Rep. at 24.

Dr. Tornatore maintained that Petitioner’s medical history was consistent with his
causation theory. Tornatore First Rep. at 21. Petitioner had no antecedent events to her second
episode of GBS other than the Tdap vaccination. Id. Additionally, one of Petitioner’s treaters, Dr.
Smith, seemed in records to allude to the possibility of vaccine-induced GBS (despite some
contentions that Ms. Dennington had characteristics of CIDP). Id.; Ex. 9 at 34, 39.

Finally, Dr. Tornatore deemed the timeframe for Petitioner’s symptoms onset—within 48
hours of vaccination—to be medically acceptable. Tornatore First Rep. at 24–25; Ex. 6 at 11–15;
Ex. 7 at 136–37. He opined that since her immune system was previously primed by earlier
exposure to the Tdap vaccine, a quick response to a second antigenic challenge could be anticipated
within 24 hours, so the rapidity with which Ms. Dennington’s symptoms was consistent with that
timeframe. Tornatore First Rep. at 24. To support this assertion, he relied on literature discussing
the acceleration of the immune response after previous exposure, and most notably a piece of
literature cited widely in the Program that is over forty years old, and which I have previously
discussed relies on a flu vaccine that has not generally been administered since the 1970s.
Schonberger at 105 (reviewing the onset of inflammatory demyelinating polyneuropathies
following swine flu vaccination). 9

9
Dr. Tornatore also referenced two other items of literature, although one was not filed and the other did not reference
the assertions he claimed (by my estimation, and due to the misfiling of specific pages). Tornatore First Rep. at 25;
See generally Institute of Medicine, Adverse Effects of Vaccines: Evidence and Causality 39, 39–54 (Kathleen R.
Stratton et al., eds., 2011), filed as Ex. 47 (ECF No. 47-9) (“IOM Report”) (discussing the assessment of
epidemiologic, clinical, and biological evidence in regard to determining a causal relationship between vaccination
and injury, but not the assertions Dr. Tornatore stated regarding timeframe).

9
 Second Report

Dr. Tornatore’s Second Report endeavored specifically to defend GBS as the proper
diagnosis. Tornatore Second Rep. at 1–3. He noted that Petitioner’s September 2, 2015 EMG
results evidenced the presence of an acute inflammatory process of the proximal nerve roots. Ex.
9 at 48–49. Petitioner was also treated with five doses of IVIG immediately following her EMG
report—the standard of care for GBS. Ex. 7 at 171, 396–70. A follow-up EMG on April 6, 2016,
showed evidence of improvement, which was another indicator to Dr. Tornatore that Petitioner
had GBS (since it bulwarked both the effectiveness of the immunotherapy treatment plus the
monophasic course of her illness). Ex. 9 at 27.

Respondent’s expert, Dr. Timothy Vartanian, had disagreed with Dr. Tornatore’s
assessment that Petitioner had a recurrent autoimmune neuropathy, but Dr. Tornatore’s opinion
remained unchanged. Tornatore Second Rep. at 2–3. Dr. Tornatore noted, for example, her
discharge status on September 6, 2015, which expressed a “concern for a possible recurrence of
GBS,” and a note from Dr. Smith that when Petitioner was hospitalized the differential indicated
“recurrent GBS vs. CIDP.” Ex. 7 at 370; Ex. 9 at 39.

In regard to his medical theory, Dr. Tornatore pointed out that Dr. Vartanian did not dispute
the scientific mechanisms of molecular mimicry as a scientific principle, suggesting he concurred
that it was reputable. Dr. Tornatore Second Rep. at 4; Vartanian Rep. at 14. And although Dr.
Vartanian asserted there was a lack of epidemiologic data to support an association between GBS
and Tdap, Dr. Tornatore argued that epidemiology cannot rule out rare events such as vaccine
injuries. Tornatore Second Rep. at 4.

Finally, with regard to onset, Dr. Tornatore disagreed with Dr. Vartanian’s assessment that
the immune response could not result in a neurologic injury within 48 hours of vaccination.
Tornatore Second Rep. at 4. Rather, immediately after re-exposure to a foreign antigen, there is a
measurable increase in the immune response, thus making Petitioner’s onset of symptoms
medically acceptable. Id.

B. Respondent’s Expert – Timothy Vartanian, M.D., Ph.D.

Dr. Vartanian, a board-certified neurologist with subspecialties in caring for patients with
inflammatory demyelinating diseases, prepared one written report for Respondent in support of
the contention that there is not a casual association between the Tdap vaccine and GBS. Report,
dated September 30, 2021, filed as Ex. A (ECF No. 41-1) (“Vartanian Rep.”).

Dr. Vartanian received his bachelor’s degree from Oakland University, along with his
medical and doctorate degree from the University of Chicago. Curriculum Vitae, filed as Ex. B on

10
November 8, 2021 (ECF No. 42-21) (“Vartanian CV”) at 1; Vartanian Rep. at 1. He completed a
residency at Massachusetts General Hospital in Neurology. Vartanian CV at 2; Vartanian Rep. at
1. He then completed two fellowships, the first at Beth Israel Hospital and the second at Harvard
Medical School. Vartanian CV at 2. Since 2009, Dr. Vartanian holds positions as a Professor at
Weill Cornell Medicine. and an attending neurologist at New York Presbyterian Hospital.
Vartanian CV at 2; Vartanian Rep. at 1. He has published a substantial number of peer-reviewed
articles. Vartanian CV at 11–23.

Like Dr. Tornatore, Dr. Vartanian engaged in a thorough review of Petitioner’s medical
history. Vartanian Rep. at 2–10. He noted that GBS is an acute inflammatory demyelinating
polyneuropathy typically triggered by an antecedent infection. Id. at 12. A classic clinical history
is that of an individual who suffers a common infection and then two weeks later begins to note
weakness in their distal lower limbs. Id.; P. van Doorn, Diagnosis, Treatment and Prognosis of
Guillain-Barré Syndrome (GBS), La Presse Médicale e193, e194 (2013), filed as Ex. A, Tab 17
(ECF No. 42-17) (“van Doorn”).

Dr. Vartanian agreed that Petitioner’s clinical presentation in 2005 was consistent with
GBS. Vartanian Rep. at 11. Testing of Petitioner’s CSF at that time showed acellularity and
elevated protein levels—hallmarks of GBS. Id.; Ex. 16 at 20. Her presentation was asymmetric,
and included an unusual finding with enhancement of the seventh and eighth nerve complex,
resulting in uncommon facial symptoms, but case report evidence showed this was possible. Ex. 9
at 27; T. Takazawa et al., Sudden Deafness and Facial Diplegia in Guillain-Barré Syndrome:
Radiological Depiction of Facial and Acoustic Nerve Lesions, 51 Internal Med. 2433, 2437 (2012),
filed as Ex. A, Tab 16 (ECF No. 42-16).

In 2015, Petitioner’s EMG/NCS also revealed characteristic findings associated with GBS.
Vartanian Rep. at 11; Ex. 9 at 48–49. Dr. Vartanian maintained, however, that subsequent testing
and the medical record did not establish evolution of her symptoms suggestive of new autoimmune
or inflammatory demyelination. Vartanian Rep. at 11; Ex. 9 at 48–49. Petitioner’s clinical course,
coupled with results of repeat EMGs, did not support the conclusion that Petitioner experienced a
recurrent autoimmune neuropathy characterized as GBS, although Dr. Vartanian did not elaborate
on what a correct diagnosis for her symptoms at this time might be. Vartanian Rep. at 11.

In addition, Dr. Vartanian maintained that there was an absence of a causal relationship
between the Tdap vaccine and GBS (independent of his questions about the proper diagnosis).
Vartanian Rep. at 14. He began with a discussion of molecular mimicry, which he allowed applies
to many examples of autoimmunity triggered by infection. Id. at 12–13. In essence (and specific
to demyelinating autoimmune illnesses like GBS), molecular mimicry occurs when a molecular

11
motif found in an infectious or foreign agent 10 resembles a similar motif present in the peripheral
nervous system myelin, raising the potential that antibodies generated against the foreign antigen
will mistakenly attack the peripheral myelin. Id. at 13.

However, Dr. Vartanian maintained, reliable literature 11 did not support the contention that
the Tdap vaccine could instigate an autoimmune process mediated by molecular mimicry and lead
to GBS. See, e.g., Vartanian Rep. at 14–16; W. Yih et al., An Assessment of the Safety of Adolescent
and Adult Tetanus–Diphtheria–Acellular Pertussis (Tdap) Vaccine, Using Active Surveillance for
Adverse Events in the Vaccine Safety Datalink, 27 Vaccine 4257, 4261 (2009), filed as Ex. A, Tab
18 (ECF No. 42-8) (“Yih”) (“[w]e found no evidence of an association between Tdap and any of
the five predefined adverse events [including GBS] in a surveillance period that included 660,245
doses of Tdap over the course of 145 weeks”); J. Nelson et al., Adapting Group Sequential Methods
to Observational Postlicensure Vaccine Safety Surveillance: Results of a Pentavalent Combination
Dtap-IPV-Hib Vaccine Safety Study, 177 Am. J. Epidemiology 131, 131 (2013), filed as Ex. A,
Tab 13 (ECF No. 42-13) (“Nelson”) (“[n]o increased risk was detected among 149,337 DTaP-
IPV-Hib vaccinees versus historical comparators for any outcome, including . . . Guillain-Barré
syndrome . . . .”); J. 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,
2045–47 (1997), filed as Ex. D (ECF No. 58-1) (concluding that if an association exists, it must
be extremely rare and not of public health significance); M. Daley et al., Safety of Diphtheria,
Tetanus, Acellular Pertussis and Inactivated Poliovirus (Dtap–IPV) Vaccine, 32 Vaccine 3019,
3019 (2014), filed as Ex. A, Tab 6 (ECF No. 42-6) (“Daley”) (“. . . there was no evidence of
increased risk for any of the pre-specified adverse events monitored.”); R. Baxter et al., Lack of
Association of Guillain-Barre Syndrome with Vaccinations, 57 Clinical Infection Diseases 197,
197 (2013), filed as Ex. A, Tab 1 (ECF No. 42-1) (“Baxter”) (finding no evidence of an increased
risk of GBS following vaccinations of any kind).

In addition, Dr. Vartanian maintained that Petitioner’s medical history was unsupportive
of the conclusion that the Tdap vaccine had caused her injury. Vartanian Rep at 11. He noted that
the etiology of Petitioner’s earlier GBS case in 2005 was mistakenly attributed to a vaccination
that the record did not corroborate as having occurred, while the notes contemporaneous with that

10
Most commonly in GBS, the infectious agent is bacterial, viral, or fungal. Vartanian Rep. at 14. Half the time an
antecedent infection is not reported nor is there recent vaccination, and in these cases, it is thought that subclinical
infection is driving autoimmunity. Id.
11
One piece of literature Dr. Vartanian referenced was an IOM Report, but it was not filed by Respondent (and as
noted earlier Petitioner did not cite to the accurate page numbers to support this assertion). However, some of
Respondent’s literature cites to IOM Reports, which (according to those authors) found the evidence inadequate to
accept or reject a causal relationship. S. Chang et al., U.S. Postlicensure Safety Surveillance for Adolescent and Adult
Tetanus, Diphtheria and Acellular Pertussis Vaccines: 2005–2007, 31 Vaccine 1447, 1450 (2013), filed as Ex. A, Tab
3 (ECF No. 42-3). Ultimately, the fact that the IOM report itself was not filed means I cannot give such contentions
much weight in my overall analysis.

12
presentation acknowledged the possibility of multiple antecedent infections. Id.; Ex. 16 at 20.
Similar evidence of an antecedent infection was present in the record from her 2015 GBS incident.
Vartanian Rep. at 10 (citing a wound on her foot from a nail and reporting a subjective fever and
nausea). Dr. Vartanian also noted that antecedent gastrointestinal or respiratory infections are
widely understood by medical science to be closely associated with GBS, whereas the Tdap
vaccine has only anecdotal associations. Vartanian Rep. at 11; Baxter at 197. Thus, a prior
infection was the most likely explanation for both instances of Petitioner’s GBS. Id.

Dr. Vartanian’s opinion also included consideration of Petitioner’s onset and its
relationship to causation. Although the adaptive immune system can provide a quick response in
the event the body has previously encountered the same pathogen (or vaccine) previously, there is
still a limit to how quickly a memory response will result in an effective immune reaction.
Vartanian Rep. at 16–17. Here, the record established that Petitioner’s onset began one and a half
days after her vaccination, which Dr. Vartanian deemed too little time for humoral or cellular
immunity to cause an injury to the nervous system. Id. 12

III. Procedural History

After the case’s initiation in August 2018, Petitioner filed medical records supporting the
claim, and then Respondent’s Rule 4(c) Report was filed on November 21, 2019 (ECF No. 22).
The case was assigned to me in January 2021. Expert reports were filed through January 2022.
Thereafter I set a schedule for a ruling on the record, and the parties acceded to this method of
resolution. The parties had fully briefed the matter by August 2022, and it is now ripe for
resolution.

IV. Parties’ Arguments

Petitioner argues that she was correctly diagnosed with a recurrent autoimmune neuropathy
(GBS) based on treater encounters. Mot. at 18–22; Reply at 2–3. Petitioner also maintains that she
has met the causation-in-fact burden based on the factors established by the Federal Circuit in
Althen v. Sec'y of Health & Hum. Servs., 418 F.3d 1274 (Fed. Cir. 2005); Mot. at 22–33; Reply at
3–9. Statements from Petitioner’s expert, she purports, support the contention that the Tdap
vaccine can cause GBS via molecular mimicry. Mot. at 25–26; Reply at 3–7. This determination
is also supported by prior Program decisions. See Mohamad v. Sec'y of Health & Hum. Servs., No.
16-1075V, 2022 WL 711604, *17–18 (Fed. Cl. Spec. Mstr. Jan. 27, 2022).

Ms. Dennington next claims that she has demonstrated a logical sequence of cause and
effect that the Tdap vaccine “did cause” her injury. Mot. at 27–31; Reply at 7–8. In support, she
notes that treating physicians allowed for the possibility that the vaccine was related to her injuries.

12
Dr. Vartanian also cited to a “Abolhassani 2020” article in support of this contention, but it was not filed.

13
Mot. at 31. Petitioner and her mother also report that shortly before the onset of GBS symptoms
in 2005, Petitioner had received a tetanus vaccine and had a flu-like illness—not coincidental, in
Petitioner’s view, and demonstrated evidence of a rechallenge. 13 Mot. at 27–29; Reply at 7. This
makes it likely that Petitioner experienced a quick onset of symptoms after her second vaccine
exposure because her immune system was previously primed with the tetanus toxoid antigen. Mot.
at 29–30; Reply at 8. Additionally, Petitioner observes that she presented with similar symptoms
in 2015 as she did in 2005. Mot. at 30–31. Finally, the timing of her onset—approximately 48
hours after receiving her Tdap vaccine—is medically-acceptable. Mot. 31–33; Reply at 8–9.

In opposing entitlement, Respondent questions the factual basis for the alleged injury,
maintaining that Ms. Dennington’s test results and medical records are not consistent with
recurrent GBS (or GBS generally for that matter). Opp. at 16–17. Additionally, Petitioner has not
preponderantly established a reliable medical theory causally connecting her vaccination to GBS.
Id. at 18. Petitioner relies on the theory of molecular mimicry too generally and does not support
such assertions with reliable literature specific to the Tdap vaccine. Id. at 18–19. Respondent also
cites to previous cases involving the Tdap vaccine and GBS, in which petitioners failed to produce
reliable scientific evidence to establish causation. See, e.g., Tompkins v. Sec'y of Health & Hum.
Servs., No. 10-261V, 2013 WL 3498652 (Fed. Cl. Spec. Mstr. June 21, 2013), mot. for review
den’d, 117 Fed. Cl. 713 (2014); Isaac v. Sec'y of Health & Hum. Servs., No. 08-601V, 2012 WL
3609993 (Fed. Cl. Spec. Mstr. July 30, 2012), mot. for review den’d, 108 Fed. Cl. 743 (2013),
aff’d, 540 F. App’x 999 (Fed. Cir. 2013). Respondent distinguishes these cases from Mohamad,
where Respondent effectively conceded Althen prong one (despite the special master not finding
the theory persuasive), and where the matter turned on literature not offered in this case. Opp. at
20; Mohamad, 2022 WL 711604, *17–18.

Under Althen prong two, Respondent argues, Petitioner’s reported onset occurred in the
context of an upper respiratory infection (along with other symptoms), which is more likely the
cause of her injury. Opp. at 21–22. Petitioner’s rechallenge argument is not supported by the
medical records as there was no indication of any vaccine received by Petitioner prior to the onset
of Petitioner’s symptoms in 2005. Id. at 21. And Petitioner’s showing under Althen prong three
also fails because it relies on evidence linking GBS and the 1976 H1N1 flu vaccine—a completely
different vaccine that does not contain any aluminum adjuvant. Id. at 24. Otherwise, onset would
be expected to occur within four days 14 at the soonest, but Petitioner’s reported symptoms occurred

13
See generally Nussman v. Sec'y of Health & Hum. Servs., No. 99-500V, 2008 WL 449656, at *9 (Fed. Cl. Spec.
Mstr. Jan. 31, 2008), aff'd, 83 Fed. Cl. 111 (2008) (defining challenge-rechallenge as “when a person (1) is exposed
to one antigen, (2) reacts to that antigen in a particular way, (3) is given the same antigen again, and (4) reacts to that
antigen similarly”).
14
As noted earlier, Dr. Vartanian’s citation to “Abolhassani 2020” was referenced to support this timeframe, but this
literature was never filed.

14
two days after vaccination, which does not fit with the current understanding of immunology and
neurology. Id.

V. Applicable Legal Standards
A. Petitioner’s Overall Burden in Vaccine Program Cases
To receive compensation in the Vaccine Program, a petitioner must prove either: (1) that
he suffered a “Table Injury”—i.e., an injury falling within the Vaccine Injury Table—
corresponding to one of the vaccinations in question within a statutorily prescribed period of time
or, in the alternative, (2) that his illnesses were actually caused by a vaccine (a “Non-Table
Injury”). See Sections 13(a)(1)(A), 11(c)(1), and 14(a), as amended by 42 C.F.R. § 100.3; §
11(c)(1)(C)(ii)(I); see also Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315, 1321 (Fed.
Cir. 2010); Capizzano v. Sec’y of Health & Hum. Servs., 440 F.3d 1317, 1320 (Fed. Cir. 2006). 15
In this case, Petitioner does not assert a Table claim.

For both Table and Non-Table claims, Vaccine Program petitioners bear a “preponderance
of the evidence” burden of proof. Section 13(1)(a). That is, a petitioner must offer evidence that
leads the “trier of fact to believe that the existence of a fact is more probable than its nonexistence
before [he] may find in favor of the party who has the burden to persuade the judge of the fact’s
existence.” Moberly, 592 F.3d at 1322 n.2; see also Snowbank Enter. v. United States, 6 Cl. Ct.
476, 486 (1984) (mere conjecture or speculation is insufficient under a preponderance standard).
Proof of medical certainty is not required. Bunting v. Sec’y of Health & Hum. Servs., 931 F.2d
867, 873 (Fed. Cir. 1991). In particular, a petitioner must demonstrate that the vaccine was “not
only [the] but-for cause of the injury but also a substantial factor in bringing about the injury.”
Moberly, 592 F.3d at 1321 (quoting Shyface v. Sec’y of Health & Hum. Servs., 165 F.3d 1344,
1352–53 (Fed. Cir. 1999)); Pafford v. Sec’y of Health & Hum. Servs., 451 F.3d 1352, 1355 (Fed.
Cir. 2006). A petitioner may not receive a Vaccine Program award based solely on his assertions;
rather, the petition must be supported by either medical records or by the opinion of a competent
physician. Section 13(a)(1).

In attempting to establish entitlement to a Vaccine Program award of compensation for a
Non-Table claim, a petitioner must satisfy all three of the elements established by the Federal
Circuit in Althen, 418 F.3d at 1278: “(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.”

15
Decisions of special masters (some of which I reference in this ruling) constitute persuasive but not binding
authority. Hanlon v. Sec’y of Health & Hum. Servs., 40 Fed. Cl. 625, 630 (1998). By contrast, Federal Circuit rulings
concerning legal issues are binding on special masters. Guillory v. Sec’y of Health & Hum. Servs., 59 Fed. Cl. 121,
124 (2003), aff’d 104 F. Appx. 712 (Fed. Cir. 2004); see also Spooner v. Sec’y of Health & Hum. Servs., No. 13-159V,
2014 WL 504728, at *7 n.12 (Fed. Cl. Spec. Mstr. Jan. 16, 2014).

15
 Each of the Althen prongs requires a different showing. 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, a
petitioner’s theory must be based on a “sound and reliable medical or scientific explanation.”
Knudsen v. Sec’y of Health & Hum. 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 & Hum. Servs., 569 F.3d 1367, 1378–79 (Fed. Cir. 2009) (citing
Capizzano, 440 F.3d at 1325–26). Special masters, despite their expertise, are not empowered by
statute to conclusively resolve what are essentially thorny scientific and medical questions, and
thus 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. Accordingly, special masters must take care not to increase the burden
placed on petitioners in offering a scientific theory linking vaccine to injury. Contreras, 121 Fed.
Cl. at 245.

In discussing the evidentiary standard applicable to the first Althen prong, the Federal
Circuit has consistently rejected the contention that it can be satisfied merely by establishing the
proposed causal theory’s scientific or medical plausibility. See Boatmon v. Sec’y of Health & Hum.
Servs., 941 F.3d 1351, 1359 (Fed. Cir. 2019); see also LaLonde v. Sec’y of Health & Hum. Servs.,
746 F.3d 1334, 1339 (Fed. Cir. 2014) (“[h]owever, in the past we have made clear that simply
identifying a ‘plausible’ theory of causation is insufficient for a petitioner to meet her burden of
proof” (citing Moberly, 592 F.3d at 1322)); Howard v. Sec'y of Health & Hum. Servs., No. 16-
1592V, slip op. (Fed. Cl. Feb. 27, 2023) (affirming dismissal of a Tdap-CIDP case, and confirming
that “[t]he standard has been preponderance for nearly four decades”). Otherwise, petitioners always
have the ultimate burden of establishing their Vaccine Act claim with preponderant evidence. W.C.
v. Sec’y of Health & Hum. Servs., 704 F.3d 1352, 1356 (Fed. Cir. 2013) (citations omitted); Tarsell
v. United States, 133 Fed. Cl. 782, 793 (2017) (noting that Moberly “addresses the petitioner’s
overall burden of proving causation-in-fact under the Vaccine Act” by a preponderance standard).

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 & Hum. 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

16
‘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 & Hum. Servs., 993 F.2d 1525, 1528 (Fed. Cir. 1993).

Medical records and statements of a treating physician, however, 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. Section 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 & Hum. 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 be weighed against other, contrary
evidence also present in the record—including conflicting opinions among such individuals.
Hibbard v. Sec’y of Health & Hum. 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); Veryzer v. Sec’y of Dept. of Health & Hum. Servs., No. 06-522V,
2011 WL 1935813, at *17 (Fed. Cl. Spec. Mstr. Apr. 29, 2011), mot. for review denied, 100 Fed.
Cl. 344, 356 (2011), aff’d without opinion, 475 F. Appx. 765 (Fed. Cir. 2012).

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.” de Bazan
v. Sec’y of Health & Hum. Servs., 539 F.3d 1347, 1352 (Fed. Cir. 2008). The explanation for what
is a medically acceptable timeframe must align 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 & Hum.
Servs., 101 Fed. Cl. 532, 542 (2011), recons. denied after remand, 105 Fed. Cl. 353 (2012), aff’d
mem., 503 F. Appx. 952 (Fed. Cir. 2013); Koehn v. Sec’y of Health & Hum. Servs., No. 11-355V,
2013 WL 3214877 (Fed. Cl. Spec. Mstr. May 30, 2013), mot. for rev. denied (Fed. Cl. Dec. 3,
2013), aff’d, 773 F.3d 1239 (Fed. Cir. 2014).

B. Legal Standards Governing Factual Determinations

The process for making determinations in Vaccine Program cases regarding factual issues
begins with consideration of the medical records. Section 11(c)(2). The special master is required
to consider “all [ ] relevant medical and scientific evidence contained in the record,” including
“any diagnosis, conclusion, medical judgment, or autopsy or coroner's report which is contained

17
in the record regarding the nature, causation, and aggravation of the petitioner's illness, disability,
injury, condition, or death,” as well as the “results of any diagnostic or evaluative test which are
contained in the record and the summaries and conclusions.” Section 13(b)(1)(A). The special
master is then required to weigh the evidence presented, including contemporaneous medical
records and testimony. See Burns v. Sec'y of Health & Hum. Servs., 3 F.3d 415, 417 (Fed. Cir.
1993) (determining that it is within the special master's discretion to determine whether to afford
greater weight to contemporaneous medical records than to other evidence, such as oral testimony
surrounding the events in question that was given at a later date, provided that such determination
is evidenced by a rational determination).

As noted by the Federal Circuit, “[m]edical records, in general, warrant consideration as
trustworthy evidence.” Cucuras, 993 F.2d at 1528; Doe/70 v. Sec'y of Health & Hum. Servs., 95
Fed. Cl. 598, 608 (2010) (“[g]iven the inconsistencies between petitioner's testimony and his
contemporaneous medical records, the special master's decision to rely on petitioner's medical
records was rational and consistent with applicable law”), aff'd, Rickett v. Sec'y of Health & Hum.
Servs., 468 F. App’x 952 (Fed. Cir. 2011) (non-precedential opinion). A series of linked
propositions explains why such records deserve some weight: (i) sick people visit medical
professionals; (ii) sick people attempt to honestly report their health problems to those
professionals; and (iii) medical professionals record what they are told or observe when examining
their patients in as accurate a manner as possible, so that they are aware of enough relevant facts
to make appropriate treatment decisions. Sanchez v. Sec'y of Health & Hum. Servs., No. 11–685V,
2013 WL 1880825, at *2 (Fed. Cl. Spec. Mstr. Apr. 10, 2013); Cucuras v. Sec'y of Health & Hum.
Servs., 26 Cl. Ct. 537, 543 (1992), aff'd, 993 F.2d at 1525 (Fed. Cir. 1993) (“[i]t strains reason to
conclude that petitioners would fail to accurately report the onset of their daughter's symptoms”).

Accordingly, if the medical records are clear, consistent, and complete, then they should
be afforded substantial weight. Lowrie v. Sec'y of Health & Hum. Servs., No. 03–1585V, 2005 WL
6117475, at *20 (Fed. Cl. Spec. Mstr. Dec. 12, 2005). Indeed, contemporaneous medical records
are often found to be deserving of greater evidentiary weight than oral testimony—especially
where such testimony conflicts with the record evidence. Cucuras, 993 F.2d at 1528; see also
Murphy v. Sec'y of Health & Hum. Servs., 23 Cl. Ct. 726, 733 (1991), aff'd per curiam, 968 F.2d
1226 (Fed. Cir. 1992), cert. den'd, Murphy v. Sullivan, 506 U.S. 974 (1992) (citing United States
v. United States Gypsum Co., 333 U.S. 364, 396 (1947) (“[i]t has generally been held that oral
testimony which is in conflict with contemporaneous documents is entitled to little evidentiary
weight.”)).

However, the Federal Circuit has also noted that there is no formal “presumption” that
records are accurate or superior on their face to other forms of evidence. Kirby v. Sec’y of Health
& Hum. Servs., 997 F.3d 1378, 1383 (Fed. Cir. 2021). There are certainly situations in which
compelling oral or written testimony (provided in the form of an affidavit or declaration) may be

18
more persuasive than written records, such as where records are deemed to be incomplete or
inaccurate. Campbell v. Sec'y of Health & Hum. Servs., 69 Fed. Cl. 775, 779 (2006) (“like any
norm based upon common sense and experience, this rule should not be treated as an absolute and
must yield where the factual predicates for its application are weak or lacking”); Lowrie, 2005 WL
6117475, at *19 (“[w]ritten records which are, themselves, inconsistent, should be accorded less
deference than those which are internally consistent”) (quoting Murphy, 23 Cl. Ct. at 733)).
Ultimately, a determination regarding a witness's credibility is needed when determining the
weight that such testimony should be afforded. Andreu, 569 F.3d at 1379; Bradley v. Sec'y of
Health & Hum. Servs., 991 F.2d 1570, 1575 (Fed. Cir. 1993).

When witness testimony is offered to overcome the presumption of accuracy afforded to
contemporaneous medical records, such testimony must be “consistent, clear, cogent, and
compelling.” Sanchez, 2013 WL 1880825, at *3 (citing Blutstein v. Sec'y of Health & Hum. Servs.,
No. 90–2808V, 1998 WL 408611, at *5 (Fed. Cl. Spec. Mstr. June 30, 1998)). In determining the
accuracy and completeness of medical records, the Court of Federal Claims has listed four possible
explanations for inconsistencies between contemporaneously created medical records and later
testimony: (1) a person's failure to recount to the medical professional everything that happened
during the relevant time period; (2) the medical professional's failure to document everything
reported to her or him; (3) a person's faulty recollection of the events when presenting testimony;
or (4) a person's purposeful recounting of symptoms that did not exist. La Londe v. Sec'y of Health
& Hum. Servs., 110 Fed. Cl. 184, 203–04 (2013), aff'd, 746 F.3d 1334 (Fed. Cir. 2014). In making
a determination regarding whether to afford greater weight to contemporaneous medical records
or other evidence, such as testimony at hearing, there must be evidence that this decision was the
result of a rational determination. Burns, 3 F.3d at 417.

C. Analysis of Expert Testimony

Establishing a sound and reliable medical theory often requires a petitioner to present
expert testimony in support of his claim. Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357,
1361 (Fed. Cir. 2000). Vaccine Program expert testimony is usually evaluated according to the
factors for analyzing scientific reliability set forth in Daubert v. Merrell Dow Pharm., Inc., 509
U.S. 579, 594–96 (1993). See Cedillo v. Sec’y of Health & Hum. Servs., 617 F.3d 1328, 1339 (Fed.
Cir. 2010) (citing Terran v. Sec’y of Health & Hum. Servs., 195 F.3d 1302, 1316 (Fed. Cir. 1999).
Under Daubert, the factors for analyzing the reliability of testimony are:

(1) whether a theory or technique can be (and has been) tested; (2) whether the
theory or technique has been subjected to peer review and publication; (3) whether
there is a known or potential rate of error and whether there are standards for
controlling the error; and (4) whether the theory or technique enjoys general
acceptance within a relevant scientific community.

19
Terran, 195 F.3d at 1316 n.2 (citing Daubert, 509 U.S. at 592–95).

In the Vaccine Program the Daubert factors play a slightly different role than they do when
applied in other federal judicial settings, like the district courts. Typically, Daubert factors are
employed by judges (in the performance of their evidentiary gatekeeper roles) to exclude evidence
that is unreliable or could confuse a jury. By contrast, in Vaccine Program cases these factors are
used in the weighing of the reliability of scientific evidence proffered. Davis v. Sec'y of Health &
Hum. Servs., 94 Fed. Cl. 53, 66–67 (2010) (“uniquely in this Circuit, the Daubert factors have
been employed also as an acceptable evidentiary-gauging tool with respect to persuasiveness of
expert testimony already admitted”). The flexible use of the Daubert factors to evaluate the
persuasiveness and reliability of expert testimony has routinely been upheld. See, e.g., Snyder, 88
Fed. Cl. at 742–45. In this matter (as in numerous other Vaccine Program cases), Daubert has not
been employed at the threshold, to determine what evidence should be admitted, but instead to
determine whether expert testimony offered is reliable and/or persuasive.

Respondent frequently offers one or more experts in order to rebut a petitioner’s case.
Where both sides offer expert testimony, a special master's decision may be “based on the
credibility of the experts and the relative persuasiveness of their competing theories.”
Broekelschen v. Sec'y of Health & Hum. Servs., 618 F.3d 1339, 1347 (Fed. Cir. 2010) (citing
Lampe, 219 F.3d at 1362). However, nothing requires the acceptance of an expert's conclusion
“connected to existing data only by the ipse dixit of the expert,” especially if “there is simply too
great an analytical gap between the data and the opinion proffered.” Snyder, 88 Fed. Cl. at 743
(quoting Gen. Elec. Co. v. Joiner, 522 U.S. 146 (1997)); see also Isaac v. Sec'y of Health & Hum.
Servs., No. 08–601V, 2012 WL 3609993, at *17 (Fed. Cl. Spec. Mstr. July 30, 2012), mot. for
review den'd, 108 Fed. Cl. 743 (2013), aff'd, 540 F. App’x. 999 (Fed. Cir. 2013) (citing Cedillo,
617 F.3d at 1339). Weighing the relative persuasiveness of competing expert testimony, based on
a particular expert's credibility, is part of the overall reliability analysis to which special masters
must subject expert testimony in Vaccine Program cases. Moberly, 592 F.3d at 1325–26
(“[a]ssessments as to the reliability of expert testimony often turn on credibility determinations”);
see also Porter v. Sec'y of Health & Hum. Servs., 663 F.3d 1242, 1250 (Fed. Cir. 2011) (“this court
has unambiguously explained that special masters are expected to consider the credibility of expert
witnesses in evaluating petitions for compensation under the Vaccine Act”).

D. Consideration of Medical Literature

Both parties filed numerous items of medical and scientific literature in this case, but not
all such items factor into the outcome of this decision. While I have reviewed all the medical
literature submitted in this case, I discuss only those articles that are most relevant to my
determination and/or are central to Petitioner’s case—just as I have not exhaustively discussed

20
every individual medical record filed. Moriarty v. Sec’y of Health & Hum. Servs., No. 2015–5072,
2016 WL 1358616, at *5 (Fed. Cir. Apr. 6, 2016) (“[w]e generally presume that a special master
considered the relevant record evidence even though he does not explicitly reference such evidence
in his decision”) (citation omitted); see also Paterek v. Sec’y of Health & Hum. Servs., 527 F.
App’x 875, 884 (Fed. Cir. 2013) (“[f]inding certain information not relevant does not lead to—
and likely undermines—the conclusion that it was not considered”).

E. Standards for Ruling on the Record

I am resolving Petitioner’s claim on the filed record, and the parties have not challenged
my determination to do so. Mot. at 1; Opp. at 1. The Vaccine Act and Rules not only contemplate
but encourage special masters to decide petitions on the papers where (in the exercise of their
discretion) they conclude that doing so will properly and fairly resolve the case. Section
12(d)(2)(D); Vaccine Rule 8(d). The decision to rule on the record in lieu of hearing has been
affirmed on appeal. Kreizenbeck v. Sec’y of Health & Hum. Servs., 945 F.3d 1362, 1366 (Fed. Cir.
2020); see also Hooker v. Sec’y of Health & Hum. Servs., No. 02-472V, 2016 WL 3456435, at *21
n.19 (Fed. Cl. Spec. Mstr. May 19, 2016) (citing numerous cases where special masters decided
case on the papers in lieu of hearing and that decision was upheld). I am simply not required to
hold a hearing in every matter, no matter the preferences of the parties. Hovey v. Sec’y of Health
& Hum. Servs., 38 Fed. Cl. 397, 402–03 (1997) (determining that special master acted within his
discretion in denying evidentiary hearing); Burns, 3 F.3d at 417; Murphy v. Sec’y of Health &
Hum. Servs., No. 90-882V, 1991 WL 71500, at *2 (Fed. Cl. Spec. Mstr. Apr. 19, 1991).

ANALYSIS

I. An Overview of Relevant Medical Terms and Applicable Prior Decisions

GBS has been defined as an acute, monophasic peripheral neuropathy involving rapidly
progressive and ascending motor neuron paralysis, which is thought to have an autoimmune
mechanism. Fokke at 34. Increased protein levels in the cerebral spinal fluid without a
corresponding increase in cells is often featured in GBS. Id. Its characteristics typically include
generalized muscle weakness combined with sensory symptoms. van Doorn at e195. GBS has an
acute onset, is monophasic, and is not steroid-responsive. Id. at e198.

There is a large body of reasoned decisions 16 affirming the existence of an association
between the flu vaccine and peripheral neuropathies—most often GBS. Indeed, GBS occurring
after receipt of a flu vaccine is the basis for a Table claim. 42 C.F.R. § 100.3.14. This means the
Government has agreed that sufficiently-probative and reliable science on the topic existed to

16
Although prior decisions from different cases do not control the outcome herein, special masters may reasonably
take into account, for guidance, the logic of reasoned entitlement determinations. In fact, it is wise to do so, given how
often similar causation theories or fact patterns arise in Vaccine Program cases.

21
justify conceding causation, at least for Program purposes. Haskins v. Secretary of Health & Hum.
Servs., No. 18-1776, 2020 WL 1870279 (Fed. Cl. Spec. Mstr. Mar. 13, 2019). Indeed, even in
cases where a Table element for a flu vaccine-GBS claim cannot be met (for example, when onset
is too short or long to fit within the timeframe of 3-42 days set for the claim), any subsequent
causation-in-fact analysis does not usually turn on the “can cause” first Althen prong. See Welch
v. Sec'y of Health & Hum. Servs., No. 18-494V, 2019 WL 349360 (Fed. Cl. Spec. Mstr. July 2,
2019).

Other vaccines have also been found causal of GBS, although there is disagreement among
the special masters as to the preponderant strength of these associations. See, e.g., Gross v. Sec'y
of Health & Hum. Servs., No. 17-1075V, 2022 WL 9669651, at *36–37 (Fed. Cl. Spec. Mstr. Sept.
22, 2022) (showing the pneumococcal vaccine caused GBS); but see Trollinger v. Sec'y of Health
& Hum. Servs., No. 16-473V, 2023 WL 2521912, at *30 (Fed. Cl. Spec. Mstr. Feb. 17, 2023),
appeal docketed, No. 16-473V, (Fed. Cl. Mar. 17, 2023) (finding that the pneumococcal vaccine
was not shown to cause GBS); Bielak v. Sec'y of Health & Hum. Servs., No. 18-761V, 2022 WL
18058244, at *34 (Fed. Cl. Spec. Mstr. Dec. 9, 2022) (same). It thus cannot be said that the
Program has developed a consistent view as to what the science preponderantly “says” about
causation when the flu vaccine is not involved. Instead, it appears that the outcome in such cases
is mostly a function of the evidence before the special master with no clear trend one way or the
other.

This is definitely true in the context of claims that the Tdap vaccine can cause GBS. Several
cases decided in the past ten years found no causal association between the two. See, e.g., Winkler
v. Sec'y of Health & Hum. Servs., No. 18-203V, 2021 WL 6276203 (Fed. Cl. Spec. Mstr. Dec. 10,
2021), mot. for review den’d, 2022 WL 1528779 (2022); Montgomery v. Sec'y of Health & Hum.
Servs., No. 15-1037V, 2019 WL 2511352 (Fed. Cl. Spec. Mstr. May 21, 2019); Tompkins, 2013
WL 3498652; Isaac, 2012 WL 3609993. 17

In Isaac, for example, the petitioner offered molecular mimicry as her causal theory. Isaac,
2012 WL 3609993, at *6. But the special master determined that Dr. Tornatore (who also served
as that petitioner’s expert) had over-relied on a case report 18 and there was an absence of focus on
molecular mimicry as a theory of vaccine injury—an allegation also made by Respondent in this
case. Id. at *20–21. This determination was affirmed on appeal at the Court of Federal Claims and
Federal Circuit. In Tompkins, the special master denied entitlement in a case alleging that a number

17
I have also decided a few cases finding no causal association between the Tdap vaccine and CIDP—albeit a different
injury from GBS. See, e.g., Howard v. Sec'y of Health & Hum. Servs., No. 16-1592V, 2022 WL 4869354 (Fed. Cl.
Spec. Mstr. Aug. 31, 2022), mot. for review den’d, slip op. (Fed. Cl. Feb. 27, 2023); Sanchez v. Sec'y of Health &
Hum. Servs., No. 18-1012V, 2022 WL 1013264, at *1 (Fed. Cl. Spec. Mstr. Mar. 11, 2022).

The case report in Isaac was also briefly referred to in this case. See J.D. Pollard & G. Selby, Relapsing Neuropathy
18

Due to Tetanus Toxoid, 37 J. Neurol. Sci. 113 (1978), filed as Ex. 43 (ECF No. 42-5).

22
of vaccines received at the same time, including the Tdap vaccine, caused a petitioner's GBS, but
the causal theory put forward attempted to assert that the vaccines could also individually trigger
the disease. Tompkins, 2013 WL 3498652, at *15. The petitioner's expert, however, relied heavily
on VAERS passive surveillance data, 19 and otherwise invoked a number of theories (molecular
mimicry, or endotoxin in tetanus-containing vaccines) that were only cursorily discussed. Id. at
*19–23.

Several cases go the other way, as Petitioner notes. In Mohamad, a special master ruled in
the petitioner's favor in a Tdap-GBS case, but almost wholly based on determination that the
Government had conceded the first Althen prong, while also emphasizing evidence of prior post-
vaccination demyelination, suggesting proof of “rechallenge.” See Mohamad v. Sec'y of Health &
Hum. Servs., No. 16-1075V, 2022 WL 711604, at *18 n.17 (Fed. Cl. Spec. Mstr. Jan. 27, 2022);
see also Swaiss v. Sec'y of Health & Hum. Servs., No. 15-286V, 2019 WL 6520791, at *23-27
(Fed. Cl. Spec. Mstr. Nov. 4, 2019) (determining a small fiber neuropathy (characterized in Swaiss
as “a variant” of GBS) could be caused by the Tdap vaccine via the mechanism of molecular
mimicry, but acknowledging that the evidence offered to associate GBS and Tdap generally was
somewhat lacking). Most recently, a special master granted entitlement, but heavily focused on a
discussion of certain reports issued by the Institute of Medicine (some of which were not filed
here), and only briefly analyzed petitioner’s theory, which relied on theories other than molecular
mimicry. Harris v. Sec'y of Health & Hum. Servs., No. 18-944V, slip op. (Fed. Cl. Spec. Mstr.
Feb. 21, 2023).

Thus, it certainly cannot be said that claims relying on the Tdap vaccine’s association with
GBS are categorically ruled out—even if it is also clear, at the threshold, that there is a meaningful
decline in the amount of reliable scientific evidence associating that vaccine to this kind of nerve
injury, when compared to what is known about GBS and the flu vaccine—and reason therefore to
doubt that any putative association is well-founded.

II. Petitioner Has Preponderantly Established Her GBS Diagnosis

It is often appropriate for a special master to first determine which alleged injury is best
supported by the evidence before applying the Althen test—particularly when the injury is

19
The Vaccine Adverse Event Reporting System (“VAERS”) is a national warning system designed to detect safety
problems in U.S.-licensed vaccines. See About VAERS, VAERS, https://vaers hhs.gov/about html (last visited Mar.
23, 2023). It is managed by both the CDC and the FDA. VAERS monitors and analyzes reports of vaccine related
injuries and side effects from both healthcare professionals and individuals. But it has been observed in the Program
that VAERS data is not particularly probative of causation unless supplemented with other reliable evidence—since
a VAERS report only establishes a temporal, post-vaccination occurrence, and thus shines no light on the possibility
of causation itself. See also Vig v. Sec'y of Health & Human Servs., No. 01–198V, 2013 WL 6596683, at *17 (Fed.
Cl. Spec. Mstr. Nov. 14, 2013) (“VAERS is a stocked pond, containing only reports of adverse events after
vaccinations but no data about the number of vaccines administered or the occurrence of the same adverse event in
individuals who have not been vaccinated”).

23
disputed—so that “the special master could subsequently determine causation relative to the
injury.” Broekelschen, 618 F.3d at 1346. In some cases, determining the injury obviates entirely
the need for any Althen analysis, since the petitioner’s claim, and causation theory, is dependent
on a finding of a specific injury. Id.

In this case, the parties dispute the proper diagnosis. Opp. at 16–17. The record best
supports Petitioner’s contention, however. First, there is ample, trustworthy treater support for
Petitioner’s preferred diagnosis. Petitioner’s treating neurologist, Dr. Smith, diagnosed Petitioner
with GBS on numerous occasions. Ex. 7 at 136–37, 140–41, 150. Although Dr. Smith later
included CIDP in his differential diagnosis in December 2015 (Ex. 9 at 37–39), he clarified a year
later his view that Petitioner did not have “ongoing CIDP,” since she had not displayed new active
lesions, and was symptomatically stable (evidence of distal demyelination was residual in nature).
Ex. 9 at 3, 30, 34. Although I am never bound to accept a treater’s opinion, I may give weight to
their views. Snyder, 88 Fed. Cl. at 746 n.67. Here, Petitioner consistently saw Dr. Smith, and he
reached conclusions that seem reasonable based upon the records in which they are set forth.

Second, the medical records largely appear consistent with the conclusion that Petitioner
was suffering from GBS. Petitioner underwent complete diagnostic workups, including labs,
MRIs, a lumbar puncture, and EMG/NCS tests. This is the evidence upon which Dr. Smith relied.
Dr. Tornatore also persuasively established that Petitioner presented with defining features of
GBS—not CIDP. The latter diagnosis has ultimately limited support in the record, even if (due
mostly to the recurrent aspect of Petitioner’s GBS, especially since she experienced two separate
instances of it over several years) CIDP was reasonably raised as a possibility.

Dr. Vartanian makes a number of points in opposition (citing to Petitioner’s test results),
but does not offer a more specific diagnostic view. He opined that results of Petitioner’s EMG
results showed evidence of her prior bout of GBS in 2005. However, Dr. Vartanian did not explain
how such residual evidence would be revealed in Petitioner’s test results ten years later. Dr.
Vartanian otherwise did not fully substantiate his argument, and provided a lackluster explanation
for why Petitioner did not have GBS despite her treaters and Dr. Tornatore, who more persuasively
supported the diagnosis with record references. At bottom, the overall record preponderates in
Petitioner’s favor on diagnosis.

III. Petitioner Has not Carried Her Burden of Proof 20

A. Althen Prong One

Petitioner has not established that the Tdap vaccine could cause GBS with sufficient
reliable scientific or medical evidence. This does not mean that some of her causation contentions

20
I address the three prongs in order of their importance to my decision.

24
lacked trustworthy or reliable support. The core concept of molecular mimicry is a reliable theory
for how some autoimmune diseases occur, and it has in other contexts been persuasively connected
to vaccination, which due to antigenic similarity between a vaccine component and self structure,
could result in an autoimmune cross-attack.

However, I have now repeatedly observed in Program cases that more must be done to
preponderantly establish causation than simply “raise the flag” of molecular mimicry as a
generally-reliable concept. See, e.g., McKown v. Sec'y of Health & Hum. Servs., No. 15-1451V,
2019 WL 4072113, at *50 (Fed. Cl. Spec. Mstr. July 15, 2019) (citing Devonshire v. Sec'y of
Health & Hum. Servs., No. 99-031V, 2006 WL 2970418, at *15 (Fed. Cl. Spec. Mstr. Sept. 2006))
(“[b]ut merely chanting the magic words ‘molecular mimicry’ in a Vaccine Act case does not
render a causation theory scientifically reliable, absent additional evidence specifically tying the
mechanism to the injury and/or vaccine in question”) (emphasis in original), mot. for review den’d,
76 Fed. Cl. 452 (2007)). Instead, claimants and their experts must provide sufficient connective
evidence to allow a conclusion that it is “more likely than not” the specific vaccine in question that
could cause the relevant injury.

Dr. Tornatore was well qualified to offer the opinion he did, but he did not attempt to
establish the kind of homology between vaccine antigens and self structures in the nerves that is a
common starting point for molecular mimicry when offered as a mechanistic explanation. He also
pointed to no specific antibody created in response to the Tdap vaccine that might cross-react
against nerve myelin in the manner GBS is believed to progress. Rather, he unpersuasively argued
that because Dr. Vartanian did not dispute the scientific principles behind molecular mimicry,
Respondent had effectively conceded the existence of a causal relationship between the Tdap
vaccine and GBS. Tornatore Second Rep. at 14. But as noted above, molecular mimicry’s
reliability per se does not mean it explains how every covered vaccine could cause any
autoimmune condition.

Dr. Tornatore also relied on case reports regarding peripheral neuropathies following other
vaccinations to prove his theory. But it is well established that case report evidence is only weakly
probative of causation. See, e.g., Pearson v. Sec’y of Health & Human Servs., No. 17-489V, 2019
WL 1150044, at *11 (Fed. Cl. Spec. Mstr. Feb. 7, 2019) (concluding that case reports receive only
limited evidentiary weight and cannot cure Althen prong one deficiencies); Harris v. Sec’y of
Health & Human Servs., No. 10-322V, 2014 WL 3159377, at *18 (Fed. Cl. Spec. Mstr. June 10,
2014) (“case reports are generally not a valuable form of evidence”). And those Petitioner offered
were not specific to the Tdap vaccine, further diminishing their evidentiary value. See, e.g., Shaw
at 344–50; Khamaisi at 768–79.

Dr. Vartanian, by contrast, offered a more persuasive argument on the causation side of the
case than with respect to his diagnostic opinion. In particular, he referenced several pieces of

25
reliable literature which did not observe an association between the Tdap vaccine and injury. See,
e.g., Yih at 4261; Nelson at 131; Daley at 3019. While it is almost a bromide in Program cases that
epidemiologic studies are never a required kind of proof that claimants must offer to meet their
burden, they can be considered when they exist—and given weight if they are reliable and do not
support causation, as here. King v. Sec'y of Health & Hum. Servs., No. 03-584V, 2010 WL 892296,
at *74 (Fed. Cl. Spec. Mstr. Mar. 12, 2010) (“[c]onsistent with the teachings of Daubert, Terran,
and Grant, special masters have routinely found that epidemiologic evidence, and/or other medical
journal articles, while not dispositive, should be considered in evaluating scientific theories.”).

This is not the first case in which a petitioner has unsuccessfully attempted to argue that
the Tdap vaccine can cause GBS. While prior determinations do not determine the outcome, in the
end I see no evidence offered herein more persuasive on this question than what I have previously
considered. Even if it remains debatable whether this vaccine can have the same pathologic impact
as evidence indicates the flu vaccine does, Petitioner’s showing in this case is insufficient for me
to find this Althen prong was satisfied.

B. Althen Prong Three

The experts agreed that Petitioner experienced onset occurring within 48 hours of
vaccination, but disputed whether this timeframe was medically acceptable. Dr. Vartanian argued
that the adaptive immune response cannot respond so quickly, whereas Dr. Tornatore found that
an even more rapid response was acceptable (assuming that Petitioner had experienced rechallenge
to the Tdap vaccine).

After review of the evidence, I deem Respondent’s position more persuasive. An
autoimmune cross-reaction with molecular mimicry as its mechanism would rely on an adaptive
response (in which the immune system must first “see” the presenting antigen in the vaccine, then
generate antibodies that can lead the attack on self nerve tissues) 21 that would not have run its
course within two days such that symptoms of the demyelinating damage central to GBS would
manifest. Such a short timeframe is simply too quick, as I have found in comparable cases. See,
e.g., Rowan v. Sec'y of Health & Hum. Servs., No. 17-760V, 2020 WL 2954954, at *17 (Fed. Cl.
Spec. Mstr. Apr. 28, 2020) (36-hour onset for GBS after receipt of flu vaccine not medically
acceptable). 22

21
I have previously described in detail how there is a “lag and log” phase in the adaptive immune response—“[l]ag
begins the process and is the time during which the body encounters foreign antigens and through recognition of them
initiates an adaptive process, while log is the phase when those antibodies are actually produced.” Rowan v. Sec'y of
Health & Hum. Servs., No. 17-760V, 2020 WL 2954954, at *17 (Fed. Cl. Spec. Mstr. Apr. 28, 2020) (citing Forrest
v. Sec'y of Health & Human Servs., No. 14-1016V, 2019 WL 925495, at *6 (Fed. Cl. Spec. Mstr. Jan. 28, 2019)).
22
I also note that the flu vaccine-GBS Table claim only concedes causation for GBS onsets occurring no sooner than
three days post-vaccination. 42 C.F.R. § 100.3(a)(XIV)(D). Thus, even putting aside the Althen prong one deficiencies
of this case, timing of Ms. Dennington’s onset would remain problematic, as it was in cases like Rowan.

26
 To evade this timeframe deficiency, Petitioner relied a bit on the concept of an immune
memory response to the vaccine, based on the contention (uncorroborated by record proof) that
Petitioner and/or her mother recalled her receiving a Tdap dose not long before her onset of 2005
GBS, thus establishing a “rechallenge” context (in which immune memory would result in a faster
response). See, e.g., Mot. at 27–29. But even if this vaccination event did occur, Dr. Vartanian
persuasively established that a shorter response would still take more than two days to generate
the relevant antibodies. In reaction, Dr. Tornatore attempted to substantiate his timing arguments
by relying on Schonberger, an item of literature involving only to the flu vaccine, and one that is
now more than 40 years old. Schonberger at 105. Nothing was offered by Petitioner on timing
specific to the Tdap vaccine, and Petitioner’s case reports discussing another vaccine’s (Hep. B)
GBS association in fact documented a longer onset timeframe than herein. See, e.g., Shaw at 342
(documenting GBS cases occurring within seven weeks of the most proximate vaccine dose);
Khamaisi at 767 (reporting that an individual developed GBS ten weeks after vaccination).

C. Althen Prong Two

There is treater support in Petitioner’s medical records for a vaccine causal relationship,
supportive of the “did cause” Althen prong. But I am not bound to accept a treater’s opinion.
Snyder, 88 Fed. Cl. at 746 n.67. Rather, I may weigh the basis for such a view, and need not take
it at face value simply because it was rendered contemporaneously.

Here, it appears in several instances that treaters made this reference on the basis of
representations by Petitioner or her mother that she had previously incurred post-vaccination GBS.
See Ex. 8 at 3 (“per mom [patient] was seen at TCH in 2005 with same complaints”). But as even
Petitioner admits, her 2005 records do not establish that she received the Tdap vaccine in 2005.
Mot. at 28. Indeed, the records do not even document the “same” symptoms. In 2005, Petitioner
reported that her symptoms began with a fever, headache, and neck pain before developing facial
tingling and difficulty walking, whereas Petitioner’s symptoms in 2015 began in the context of
mild pain and chills due to a wound on her foot and a two-day history of a subjective fever and
nausea, which later progressed to numbness and tingling in her lower extremities. Ex. 6 at 11, 29;
Ex. 8 at 3; Ex. 16 at 2. I thus do not find that the relevant treater views of causality were reasoned,
since they assumed a prior vaccine relationship when that underlying vaccination event cannot be
substantiated.

Contentions about the “second” dose of Tdap vaccine constituting an immune rechallenge
are also unavailing. Ex. 7 at 140, 154; Ex. 9 at 39. Dr. Tornatore’s arguments about a shorter
immune memory response (which in turn would allow for a shorter post-vaccination onset) relied
on the accuracy of assertions that Petitioner received the vaccine in 2005, but the record does not

27
substantiate that allegation. And as noted above, I otherwise determine that even in the context of
a rechallenge, onset would likely take more than two days.

Finally, I observe evidence in the record of a potential alternative explanation for her GBS
that was not adequately explained by Petitioner. 23 It was noted that Petitioner’s 2015 Tdap
vaccination was due to a rash and abscess from an “old rusty pole,” which could have caused an
intercurrent infection. Ex. 6 at 29. Even Petitioner’s own expert noted that foreign antigens like
viral or bacterial infections can result in the activation of the immune system, and in rare cases
cause the body to target its own nervous system. Tornatore First Rep. at 21–22. While I cannot
conclude there was an alternative cause for her GBS, this evidence certainly undermines any
contention that nothing else could explain it, especially since (as Dr. Vartanian maintained)
evidence of antecedent infections causing GBS is much stronger than what links GBS to vaccines.

CONCLUSION
A Program entitlement award is only appropriate for claims supported by preponderant
evidence. Here, Petitioner has not made such a showing. Petitioner is therefore not entitled to
compensation.

In the absence of a motion for review filed pursuant to RCFC Appendix B, the Clerk of the
Court SHALL ENTER JUDGMENT in accordance with the terms of this Decision. 24

IT IS SO ORDERED.

/s/ Brian H. Corcoran
Brian H. Corcoran
Chief Special Master

23
Even though petitioners are never burdened with disproving an alternative cause in their primary case, they may not
ignore alternative evidence undermining their Althen showing. See Snyder v. Sec'y of Health & Hum. Servs., 553 F.
App'x 994, 1000 (Fed. Cir. 2014) (“no evidence should be embargoed from the special master’s consideration simply
because it is also relevant to another inquiry under the statute”) (quoting Stone v. Sec'y of Health & Hum. Servs., 676
F.3d 1373, 1380 (Fed. Cir. 2012); see also de Bazan, 539 F.3d at 1353 (“[t]he government, like any defendant, is
permitted to offer evidence to demonstrate the inadequacy of the petitioner’s evidence on a requisite element of the
petitioner’s case-in-chief”). Thus, I consider this proof in weighing Petitioner’s “did cause” success—although I do
not give it substantial weight.
24
Pursuant to Vaccine Rule 11(a), the parties may expedite entry of judgment if (jointly or separately) they file notices
renouncing their right to seek review.

28