Samuels v. Secretary of Health and Human Services ( 2020 )


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  •                  In the United States Court of Federal Claims
    OFFICE OF SPECIAL MASTERS
    No. 17-071V
    (To be published)
    *****************************
    *                                             Chief Special Master Corcoran
    AMANDA SAMUELS,             *
    *
    Petitioner,  *                                             Filed: May 1, 2020
    *
    v.                *
    *                                             Entitlement Decision; Multiple
    SECRETARY OF HEALTH         *                                             Sclerosis; Acute Disseminated
    AND HUMAN SERVICES,         *                                             Encephalomyelitis; Tetanus,
    *                                             Diphtheria, Acellular Pertussis
    Respondent.  *                                             vaccine; Clinically Isolated
    *                                             Syndrome
    *****************************
    Diane Stedelnikas, Maglio Christopher & Toale, P.A., Sarasota, FL, for Petitioner.
    Catherine Stolar, U.S. Dep’t of Justice, Washington, D.C., for Respondent.
    DECISION 1
    On January 17, 2017, Amanda Samuels filed a Petition under the National Vaccine Injury
    Compensation Program (the “Vaccine Program” 2), alleging that the Tetanus-Diphtheria-acellular-
    Pertussis (“Tdap”) vaccine she received on April 23, 2014, caused her to suffer acute disseminated
    encephalomyelitis (“ADEM”) that subsequently evolved into multiple sclerosis (“MS”). Pet. at 1
    (ECF No. 1). A hearing in this matter was held on November 19, 2019.
    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
    Decision’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. 3755 (codified as amended at 42 U.S.C. §§ 300aa-10–34 (2012)) (hereinafter “Vaccine Act” or “the Act”).
    All subsequent references to sections of the Vaccine Act shall be to the pertinent subparagraph of 42 U.S.C. § 300aa.
    Having had the opportunity to review all materials filed in this case and consider the
    testimony offered at hearing, I hereby deny an entitlement award in this case. As stated in more
    detail below, there is no dispute that Petitioner’s proper overall diagnosis is MS, not ADEM. And
    she did not successfully establish that the Tdap vaccine could, or did, cause her MS—regardless
    of how its initial presentation is characterized.
    I.        Factual Background
    Ms. Samuels received the Tdap vaccine in her right deltoid from her primary care
    physician on April 23, 2014, because her sister was expecting a baby. Ex. 1 at 1. Four days later,
    on April 27, 2014, Ms. Samuels called her doctor, reporting blurry vision in the right eye,
    dizziness and nausea, and stating that her symptoms began the prior Thursday to Friday (April
    24-25, 2014—hence 24 to 48 hours post-vaccination). Ex. 5 at 113. She was referred to an
    ophthalmologist, who evaluated her on April 27, 2014. Ex. 4 at 6. She confirmed her symptoms
    began on April 24th (and also acknowledged some history of migraines), and after examination
    was diagnosed with “likely ocular migraine, episodes of increased blurry vision in the right eye,
    left frontal headache.”
    Id. at 7.
            Ms. Samuels subsequently went back to her primary care physician, who confirmed the
    ocular migraine diagnosis, and a brain MRI was ordered. Ex. 5 at 113–14. Her differential
    diagnosis now included migraines, demyelinating disease, Lyme disease, and vasculitis.
    Id. at 118,
    370. Then, on May 1, 2014, she saw a neurologist, Dr. Scott Kaplan. The results from
    imaging also came back, showing two nonspecific signals in her brain’s right lobe white matter.
    Id. at 370.
    Based on such test results and examination, Dr. Kaplan opined that Petitioner likely
    had bilateral internuclear ophthalmoplegia (“INO”). 3
    Id. at 122–23.
    He additionally noted that
    Petitioner had been vaccinated approximately one week before, timing consistent with her having
    experienced an autoimmune reaction—but also observed the possibility that (if corroborated by
    additional test results) she might have MS.
    Id. at 123.
    The records from this visit also set forth
    that Petitioner reported having recently experienced a fever, and that her entire family had been
    sick around the time she received the Tdap vaccine.
    Id. at 121.
    Petitioner next saw a neuro-ophthalmologist, Dr. Richard Feit, on May 5, 2014, reporting
    bilateral blurred vision and headaches beginning approximately eleven days prior. See generally
    Ex. 5 at 129–33. In reaction to Petitioner’s reported history and initial exam, Dr. Feit confirmed
    the INO diagnosis and indicated that he “very strongly suspect[ed]” she had experienced some
    kind of demyelinating disease process. Ex. 5 at 131. Ms. Samuels then underwent a lumbar
    puncture on May 9, 2014, and testing of her cerebrospinal fluid (“CSF”) revealed the presence
    3
    INO is the disruption of horizontal movement of the eye, usually due to a lesion in the medial longitudinal fasciculus.
    Dorland’s Illustrated Medical Dictionary 1329 (33d ed. 2020) (hereinafter Dorland’s).
    2
    of oligoclonal bands 4 (a well-known biomarker for MS).
    Id. at 137,
    140. Dr. Kaplan started Ms.
    Samuels on a five-day course of IVIG, 5 suspecting a demyelinating event but not certain that
    she was experiencing MS.
    Id. at 140,
    163. Petitioner had a follow-up MRI at a subsequent visit
    in June 2014 that revealed unremarkable results, and by this time her vision had returned to
    baseline. A diagnosis of MS could not be made because she had only experienced one event,
    but test results were suggestive of MS, and Ms. Samuels was diagnosed as having suffered a
    clinically isolated syndrome (“CIS”).
    Id. at 168–70.
    Almost six months later, on December 11, 2014, Ms. Samuels saw neurologist Dr. Jacob
    Sloane at Beth Israel Deaconess Medical Center, for evaluation and management of her suspected
    MS. Since her prior visit she had experienced some dizziness, characterized as fogginess or
    change in vision, headaches and fatigue, and a “wobbly feeling” with her eyes, but she denied
    any other problems with strength and sensation. Ex. 3 at 11. Dr. Sloane was reluctant to diagnose
    her with MS, but allowed that her existing presentation was consistent with “clinically isolated
    syndrome.”
    Id. at 3.
    Ms. Samuels presented for follow up with Dr. Sloane on multiple visits in 2015, during
    which she reported no new symptoms and had unremarkable examinations. The same was true
    for the following year. After a November 2016 visit, however, Dr. Sloane (who again observed
    no new or worsening neurological symptoms) recounted that Petitioner’s neurological
    symptoms had begun after receipt of the Tdap vaccine in April 2014, and also that her initial
    presentation (especially in light of her subsequent course) was in his view most consistent with
    an ADEM designation. Ex. 3 at 26.
    Petitioner’s treaters thereafter continued to monitor her as time passed, and she largely
    remained stable through 2017 and 2018. See, e.g., Ex. 29 at 6 (November 2017 visit with Dr.
    Sloane). Petitioner’s health took a turn for the worse, however, in February 2019, when she
    experienced a new episode of double vision with an accompanying foggy sensation. Supplemental
    Affidavit of Amanda Samuels, filed Oct. 8, 2019 (ECF No. 49-2) at 5; Ex. 38 at 3. She presented
    to Dr. Sloane for a follow-up visit on March 18, 2019, and initially it was suspected that Petitioner
    was experiencing a pseudo-flare. Ex. 40 at 1–3. However, an updated MRI revealed the presence
    of new enhancing lesions in multiple white matter areas. Ex. 37 at 6–8. Based on these recurrent
    symptoms plus the imaging evidence, treaters now embraced an MS diagnosis for Ms. Samuels,
    and she is currently being so treated. See generally Ex. 37. Dr. Sloane has, however, continued to
    4
    Oligoclonal bands are distinct bands of immunoglobulins that, when detected in CSF but are absent from serum,
    reveal antibodies associated with MS and other central nervous system diseases. Dorland’s at 197.
    5
    The abbreviation “IVIG” stands for “intravenous immunoglobulin,” and it describes a common treatment for patients
    with immune system dysfunction. See N. Davis, Medical Abbreviations 178 (15th ed. 2011).
    3
    maintain that Petitioner’s MS presented as ADEM in association with her receipt of the Tdap
    vaccine. Ex. 42 at 17.
    II.     Testimony at Hearing
    A.       Petitioner’s Witnesses
    1.       Amanda Samuels
    Ms. Samuels, an elementary school music teacher, testified at hearing on her own behalf,
    expanding on the circumstances of her illness. Tr. at 4–31. She recalled receiving the Tdap vaccine
    in April 2014, noting that she believed she had received it before in her life.
    Id. at 6–7.
    She reported
    experiencing an immediate malaise reaction 6 that same day that made her want to go to sleep early,
    followed by blurred vision the very next morning that she noticed while driving to her mother’s
    house.
    Id. at 8–9.
    The vision changes, which progressively worsened, were accompanied by
    migraine pain (a preexisting concern, albeit one she associated primarily with hormonal changes).
    Id. at 7,
    9. She did not experience a post-vaccination fever, pain, or inflammation at the site of
    vaccination, however.
    Id. at 28.
    Around this time (approximately one day post-vaccination), Ms. Samuels called her
    primary care provider about her symptoms, but was informed that it was likely just an optical
    migraine, and that she should take her existing migraine medication. Tr. at 9. However, by the
    third day post-vaccination (April 26, 2014), her symptoms (which now included balance and
    trouble walking, which she partially attributed to her underlying vision difficulties) had become
    severe enough to encourage her to take herself to an urgent care provider, at which time she was
    referred to Massachusetts Eye and Ear, but was again told that her symptoms were likely migraine-
    related.
    Id. at 10–11,
    28. She thereafter went back to her primary care physician, who obtained the
    MRI scan that first suggested the existence of a neurologic problem that could be MS.
    Id. at 11.
    Petitioner recounted the next treatment assistance she obtained. Tr. at 12–13. Dr. Kaplan
    was the first treater to inform her directly (after observing on examination lagging eye tracking)
    that her illness was more than a migraine.
    Id. at 12.
    She noted that she was telling treaters at this
    time that her change in condition had occurred after receipt of the Tdap vaccine, although she
    deemed their responses to this information “noncommittal.”
    Id. at 13.
    Eventually, Dr. Kaplan was
    able to use steroids to assist Ms. Samuels with her vision, and she recalled that his diagnostic work-
    up resulted in him proposing that she had experienced CIS.
    Id. at 13–14.
    She also learned at this
    time that although her spinal tap revealed that she possessed the oligoclonal bands associated with
    6
    Ms. Samuels also testified to having had a fainting reaction (along with arm numbness and a frozen feeling in her
    neck) after receipt of the human papillomavirus vaccine in her mid-20s but added that such symptoms subsided in less
    than one month. Tr. at 7–8. She subsequently discontinued receipt of further doses of that vaccine.
    Id. at 8.
    4
    MS, the fact that she had only experienced one clinical neurologic episode meant that an MS
    diagnosis was not yet appropriate.
    Id. She did
    not recall informing Dr. Kaplan that two weeks
    before her visit to him, her family had been sick, or that she had been suffering herself from a
    fever, although the record so indicates.
    Id. at 25–26;
    but see Ex. 5 at 121 (“[t]wo weeks ago, she
    had a fever and her whole family was sick and around the same time she also got an immunization
    Tdap.”).
    Ms. Samuels subsequently saw a second neurologist, Dr. Sloane, later that month. Tr. at
    14–15. He agreed with the CIS diagnosis, proposing a “wait and watch” responsive course of
    action.
    Id. at 15.
    As a result, although Petitioner had one January 2015 check-up visit, along with
    a few others “to make sure that nothing worse was happening” (Id.), she primarily had six-month
    follow-up visits, in May and November 2015 respectively.
    Id. at 15–16.
    Up until the latter visit,
    Ms. Samuels recalls, she was not experiencing any significant changes, but she felt particularly
    frustrated by the late fall of that year, since she was still experiencing sensitivity to light or other
    stimuli like heat, any of which could impact her vision.
    Id. at 16.
    She also continued to suspect the
    Tdap vaccine was responsible for her condition—and testified that when she mentioned it to Dr.
    Sloane, he expressed the belief that it was “what triggered my MS.”
    Id. at 17,
    24. 7
    Despite Ms. Samuels’s ongoing concerns about her health, her treaters scheduled her for a
    12-month follow-up visit for the end of 2016. Tr. at 18. During this time period, Petitioner “was
    starting to finally feel a little bit more myself.”
    Id. She became
    pregnant and gave birth in 2017,
    and follow-up examinations (including another MRI) revealed no new lesions, although treaters
    warned Ms. Samuels of the risk of a flare after pregnancy.
    Id. at 19–20.
    By this time, Petitioner’s
    overall progress convinced treaters to put her on a five-year watch and wait monitoring plan.
    Id. at 20.
    Thus, in 2018 Petitioner only saw Dr. Sloane for annual treatments.
    Id. Ms. Samuels
    did not
    testify to experiencing any new or worsened symptoms for that year.
    By the beginning of 2019, however, Petitioner began experiencing hand numbness, along
    with a recurrence of vision problems and “constant migraines.” Tr. at 21. 8 Through her primary
    care physician, she was referred to an ophthalmologist, but later went back to Dr. Sloane. At first,
    Dr. Sloane diagnosed Petitioner with experiencing a pseudo-flare associated with fatigue from her
    new motherhood responsibilities, but a subsequent MRI revealed the development of new lesions
    in her brain.
    Id. at 22.
    In reaction, Dr. Sloane now felt comfortable diagnosing Ms. Samuels with
    MS, and prescribed a corticosteroid treatment.
    Id. at 23.
    She acknowledged, however, that she has
    7
    When cross-examined, Ms. Samuels was not sure if there was a difference between Dr. Sloane proposing that the
    Tdap vaccine “triggered” her MS versus caused it. Tr. at 27–28.
    8
    Ms. Samuels suggested in her testimony that in fact she may have begun to experience some kind of symptomatic
    flare the fall of 2018, evidenced by a constant feeling of exhaustion and incontinence, but had rationalized it as relating
    to her status as a new mother. Tr. at 21.
    5
    since continued to receive other vaccines, in light of the risks she faces from her MS.
    Id. at 24.
    None of these vaccinations have produced an MS symptoms flare.
    Id. at 29.
    2.      Dr. Lawrence Steinman
    Dr. Steinman, a neurologist and immunologist, testified at hearing and filed three expert
    reports. Tr. at 31–100; Report, dated Dec. 18, 2017, filed as Ex. 6 (ECF No. 23-1) (“First Steinman
    Rep.”); Report, dated July 13, 2018, filed as Ex. 35 (ECF No. 32-3); Report, dated Oct. 5, 2019,
    filed as Ex. 43 (ECF No. 48-2). He opined that the Tdap vaccine Petitioner received caused an
    innate immune response that resulted in a CNS neurologic injury—first manifesting as ADEM,
    but later progressing to MS.
    Dr. Steinman currently serves as a professor in the departments of neurology, pediatrics,
    and genetics at Stanford University. Steinman Curriculum Vitae, filed as Ex. 44 (ECF No. 48-3)
    (“Steinman CV”) at 1. He obtained his bachelor’s degree from Dartmouth College before earning
    his medical degree from Harvard University.
    Id. He then
    completed his internship and residency
    in surgery, pediatrics, and pediatric and adult neurology at Stanford University.
    Id.
    He then
    completed several fellowships in the area of immunology.
    Id. He is
    board certified in neurology,
    though much of his work in the field also involves immunological concepts and theories.
    Id. at 2;
    Tr. at 33. Specifically, Dr. Steinman has expertise in the study of CNS disorders such as ADEM
    and MS. Tr. at 33. He estimates that he has treated thousands of patients with MS throughout his
    career.
    Id. at 34.
    Dr. Steinman currently spends approximately thirty percent of his time in clinical
    practice seeing patients, with the remainder of his time being allocated to research—for which he
    has published hundreds of articles—and administrative tasks.
    Id. The patients
    he most frequently
    sees are “one-shot-only” referrals, however, and he does not provide subsequent care following an
    initial referral.
    Id. at 34–35.
    Dr. Steinman began with a discussion of the Tdap vaccine. In addition to its bacterial
    antigen components, it contains alum, included as an adjuvant to enhance the immune response
    elicited by the vaccine. Tr. at 37, 39. The bacterial components of the vaccine are adulterated
    toxins, or “toxoids,” designed to generate an adaptive immune response, but without also inflicting
    the poisonous effects of the bacteria, and thereby provide subsequent immunologic protection from
    the “natural organism” on a subsequent exposure.
    Id. at 38–39.
    Although young children are on a
    regular schedule to get a comparable vaccine (known as “DTaP” when administered to children),
    adults are recommended to receive Tdap boosters every ten years.
    Id. at 37.
    The causation theory offered in this case relies on the initial innate response to vaccination
    attributable in part to the function of the vaccine’s adjuvant. As Dr. Steinman explained, the
    inclusion of alum in the Tdap vaccine causes the activation of certain immune cells called
    “cytokines,” and in particular IL-1β, the cytokine known to trigger “the quintessential immune
    reaction called a fever.” First Steinman Rep. at 8; Tr. at 39–40. This same cytokine is known to be
    6
    elevated in cases of CNS disease like ADEM or MS, while treatments intended to reduce the
    cytokine’s presence help to ameliorate the diseases. Tr. at 41. In his view, a similar mechanistic
    immunologic process could explain either illness (although MS is unquestionably chronic in
    character).
    Id. at 57.
    Accordingly, the core contention of Dr. Steinman’s theory was that the alum
    adjuvant prompted a pathologic immune system activation, resulting in neurologic harm
    presenting as ADEM but eventually leading to MS.
    Id. at 41.
    9
    Dr. Steinman moved on to a review of the CNS diseases at issue in this case. MS, he
    explained, was named approximately 160 years ago. Tr. at 41. It involves neurologic inflammatory
    harm in more than one location of the brain or spinal cord, and tends to be chronic, with “relapses
    and remissions.”
    Id. at 42,
    52. It usually includes symptoms impacting vision, eye and motor
    movements, bladder or bowel control, and even cognition.
    Id. at 43.
    These kinds of symptoms
    (determined by exam or history), along with imaging and tests of the CSF (particularly for evidence
    of oligoclonal bands), help to diagnose MS.
    Id. at 43–44.
    10 Most MS patients experience symptom
    relapses over time (termed “secondary progressive,” or “relapsing-remitting”), although a less
    common form (primary progressive) simply worsens progressively.
    Id. at 52.
    Dr. Steinman
    considers Petitioner’s MS to be the relapsing-remitting type.
    Id. Dr. Steinman
    acknowledged that unlike other autoimmune-mediated diseases, such as
    lupus or neuromyelitis optica, the fact that a person has MS does not necessarily mean that he or
    she also possesses an aberrant immune system. Tr. at 77–78. As he put it, “other than the fact that
    their brains get attacked, generally [their immune system] behaves pretty normally.”
    Id. at 77;
    see
    also Tr. at 79 (“you don’t get [Guillain-Barré syndrome (“GBS”)] after you develop MS”).
    Nevertheless, MS patients are treated with immunosuppressants—both because they impact the
    role the immune system plays in symptoms flare and disease progression, and also because
    scientific limits in understanding MS have prevented discovery of effective alternative therapies.
    Id. at 78–79.
    9
    Dr. Steinman denied that the causation theory he was espousing was equivalent to the theory
    “autoimmune/inflammatory syndrome induced by adjuvants,” or ASIA, despite his reliance on the alum component
    of the Tdap vaccine as perpetrating the disease, rather than the vaccine’s bacterial toxoid components. Tr. at 96. ASIA
    has been questioned in the Vaccine Program as wholly lacking in reliable scientific support. See, e.g., Yalacki v. Sec’y
    of Health & Human Servs., No. 14-278V, 
    2019 WL 1061429
    , at *24 n.30 (Fed. Cl. Spec. Mstr. Jan. 31, 2019), mot.
    for review den’d, 
    146 Fed. Cl. 80
    (2019) (noting several prior decisions in which special masters rejected the ASIA
    theory as scientifically unreliable).
    10
    Dr. Steinman provided an extended discussion of some of the specific criteria used to diagnose MS, and the issues
    with why Petitioner was not immediately so diagnosed. Tr. at 44–46. But he agreed that Ms. Samuels ultimately did
    have MS.
    Id. at 45.
    7
    Because the “first” attack does not by itself establish MS’s usual chronicity, it is often
    referred to as CIS 11—the term some of Petitioner’s treaters used to characterize her immediate
    post-vaccination symptoms.
    Id. Dr. Steinman
    , however, proposed that it was very difficult to
    distinguish ADEM from CIS at first glance, before it was known for a specific patient that the
    incident actually reflected his or her initial presentation of MS. Tr. at 42–43, 48. Thus, although
    he considered CIS to properly describe the first instance of an MS attack (Id. at 47), he termed it a
    “broad descriptor,” and proposed that (consistent with the view that CNS inflammatory disorders
    exist on a continuum) it could include other diagnoses, such as ADEM.
    Id. at 48,
    50.
    Dr. Steinman characterized ADEM as a “first cousin” or “half-brother” of CIS, an acute
    condition featuring “disseminated inflammation in the brain.” Tr. at 48. ADEM often features
    multiple brain lesions, making MRI imaging useful for diagnosis.
    Id. Encephalopathy or
    encephalitis is not required for the diagnosis, however, nor are there specific biomarkers that would
    help distinguish CIS from ADEM.
    Id. at 49.
    Dr. Steinman therefore maintained that it mattered
    little how Ms. Samuels’s initial presentation was defined, since it clearly later progressed into MS.
    Id. at 51,
    56. Dr. Sloane simply treated Petitioner as she presented over time, without concern for
    his prior diagnostic determinations.
    Id. There is,
    Dr. Steinman contended, reliable scientific support for associating the Tdap
    vaccine with certain CNS inflammatory disorders. Tr. at 46. One large-scale epidemiologic study,
    for example, observed a somewhat increased risk of ADEM in a five to twenty-eight-day window
    after receipt of Tdap—a risk that he felt was broadened given the sheer number of individuals who
    receive that vaccine. Id.; R. Baxter et al., Acute Demyelinating Events Following Vaccines: A
    Case-Centered Analysis, 63 Clinical Infectious Diseases, 1456–62 (2016), filed as Ex. 12 (ECF
    No. 19-6) (“Baxter”). Baxter evaluated instances of the occurrence of two acute demyelinating
    diseases, transverse myelitis (“TM”) and ADEM, within a field of nearly sixty-four million
    vaccinations (including almost six million Tdap recipients) derived from data maintained by the
    Vaccine Safety Datalink. Baxter at 1457. Despite its Tdap findings, Baxter nevertheless concluded
    that for all other considered vaccines (a total of 30), the risk of either demyelinating CNS injury
    after vaccine was exceedingly low.
    Id. at 1456–57.
    Although Baxter does find as Dr. Steinman represented, he acknowledged that the
    heightened incidence the study observed was lost if the interval considered was broadened to a
    range of two to forty-two days (the earlier side of which better captures Petitioner’s experience,
    since she reported onset within a day or two of vaccination). Tr. at 47; Baxter at 1460. Indeed,
    Baxter itself noted “caveats” to its finding on Tdap—in particular, (a) that there were only two
    instances in total where post-Tdap ADEM was observed, out of the nearly six-million samples,
    11
    By contrast, radiologic isolated syndrome, or “RIS,” is used to explain circumstances where an individual displays
    evidence of brain or spine lesions on an MRI but has no outward clinical manifestations of neurologic disease. Tr. at
    99.
    8
    and (b) that the two instances themselves were somewhat idiosyncratic when the specific facts of
    each were taken into account. Baxter at 1461. 12 Dr. Steinman further acknowledged that he did not
    recall if Baxter addressed MS as well as ADEM, and also agreed that if it did not consider the risk
    of post-vaccination MS, his opinion as to the article’s value herein might change. Tr. at 80. In fact,
    Baxter’s authors explicitly excluded MS patients pre- and post-vaccination from their studied
    population. Baxter at 1457.
    Looking at the relevant medical history, Dr. Steinman opined that Ms. Samuels’s own
    experiences confirmed his theory. He did not dispute Petitioner’s ultimate MS diagnosis, but noted
    that before her first constellation of symptoms, she had never displayed anything that might appear
    to be CIS or ADEM. Tr. at 53, 70. She also had no family history for autoimmune disease. He
    found especially significant the fact that, post-vaccination, she was diagnosed with INO, a
    condition characterized by eye movement limitations due to a lesion specifically located in a single
    place on the brainstem.
    Id. at 54.
    Ms. Samuels’s INO symptoms were, in Dr. Steinman’s
    estimation, critical evidence supporting his causation theory.
    Id. at 73.
    Dr. Steinman agreed, however, that INO was generally deemed a “red flag” suggesting the
    presence of MS, given its unmistakable clinical presentation.
    Id. at 75–76.
    He also admitted no
    knowledge of literature associating INO as a neurologic side-effect of the Tdap vaccine.
    Id. at 76.
    Additionally, the record establishes that Petitioner suffered from headaches in the past—and Dr.
    Steinman allowed that migraines might also explain this condition.
    Id. Her subsequent
    course—
    including a long remittance, followed by a relapse in 2019—was otherwise consistent with MS,
    and thus Petitioner’s initial post-vaccination symptoms had to be associated with her later history.
    Id. at 57–58.
    Dr. Steinman also noted that Dr. Sloane concluded in November 2015 that the vaccine
    was likely causal.
    Id. at 66.
    Dr. Steinman felt that Ms. Samuels’s ADEM was the product of a “multifactorial” process,
    combining the environmental stimulus of vaccination with a likely genetic predisposition, as well
    as her unquestionable prior exposure to the Tdap components. Tr. at 68–69, 82, 86. But he
    acknowledged that he could only assume (drawing upon his own expertise in studying MS) that
    Petitioner was predisposed to MS, and could not identify which genes specifically she might
    possess that would be involved.
    Id. at 77.
    Such assertions also contradicted his earlier emphasis
    on the fact that Ms. Samuels never displayed a propensity toward autoimmunity before her first
    MS flare—a factual omission that detracted somewhat from the conclusion she was likely to
    develop MS or some similar autoimmune condition. Ultimately, however, he was comfortable
    relying on the Tdap vaccine alone as causal.
    Id. at 87.
    12
    Specifically, one of the cases had received Tdap eleven days before onset, and the other had received it along with
    a number of other vaccines administered contemporaneously. Baxter at 1461. Baxter’s authors also noted that what
    caused the increase incidence rate was the fact that two, rather than the predicted one, case had occurred.
    Id. 9 Dr.
    Steinman also agreed that in addition to the INO symptoms, Petitioner was determined
    close in time to her first symptoms, via imaging, to have existing brain lesions—and that they were
    of “indeterminate duration.” Tr. at 83. He thus allowed for the possibility that the lesions had been
    present before Ms. Samuels received the Tdap vaccine, but downplayed the significance of this
    finding.
    Id. at 83
    (saying that the lesions might not have been “clinically relevant,” thus allowing
    the vaccine still be to causal of Petitioner’s initial symptoms), 98–99. 13 Alternatively, the observed
    lesions could be explained by the vaccine—although Dr. Steinman did not specify how they would
    have come into existence, and ultimately maintained that he “didn’t spend any time” in connection
    with the formulation of his opinion assessing the age of the lesions and the impact this would have
    on his theory.
    Id. at 83
    . He added that even though Petitioner’s treaters had not seemed to view the
    lesions as significant in diagnosing her, he “would have jumped in there and called it MS and
    treated it,” rather than ADEM or CIS.
    Id. at 84.
            Dr. Steinman also opined that the timeframe for Petitioner’s first MS-related symptoms
    was medically acceptable. He admitted that an onset within twenty-four hours, which he agreed
    the evidence supported, “requires the most explanation” of any causal component of Ms. Samuel’s
    claim. Tr. at 60, 70. To do so, Dr. Steinman relied in part on the concept of immune memory,
    which posits that prior exposure to an infectious or toxic antigen in the past makes it likely that
    subsequent exposures will cause a faster immune response.
    Id. at 61;
    First Steinman Rep. at 11.
    Prior exposure to tuberculosis or the vaccine used to combat it in Europe could, for
    example, cause a subsequent response to occur as soon as eight or twelve hours post-second
    exposure. Tr. at 61–62, 84 (referencing L. Fan et al., Variation of Mycobacterium tuberculosis
    Antigen-Specific IFN-γ and IL-17 Responses in Healthy Tuberculin Skin Test (TST)-Positive
    Human Subjects, 7 PLoS One 1, 1–6 (2012), filed as Ex. 24 (ECF No. 20-9); T. Kardjito & J.M.
    Grange, Immunological and Clinical Features of Smear-Positive Pulmonary Tuberculosis in East
    Java, 61 Tuberculosis 231, 236–37 (1980), filed as Ex. 25 (ECF No. 20-10); T. Serane & B.
    Kothendaraman, Tuberculin Test Can be Read after 24 Hours in Adolescent Children, 60 J.
    Tropical Pediatrics 157, 160 (2014), filed as Ex. 23 (ECF No. 20-8)). Dr. Steinman also referenced
    a seminal study on the onset for a peripheral neuropathy, GBS, which revealed onset for a studied
    group of individuals was as fast as one day, and that more individuals experienced such a short
    onset than experienced onset forty-two days post-vaccination. Tr. at 62; L. Schonberger et al.,
    Guillain-Barré Syndrome Following Vaccination in the National Influenza Program, United
    States, 1976-77, 110 Am. J. Epidemiology 105–23 (1979), filed as Ex. 26 (ECF No. 21-1)
    (“Schonberger”).
    13
    In so testifying, Dr. Steinman acknowledged the existence of RIS, in which a patient is inadvertently found to
    possess brain lesions without outward clinical manifestations of neurologic injury. Tr. at 99. He agreed such a person
    could live a long time without symptoms or knowledge of the lesions.
    Id. at 99–100.
                                                             10
    Here, Dr. Steinman noted, Ms. Samuels had previously received prior booster injections of
    the Tdap vaccine, likely giving her just that sort of immune memory. Tr. at 62–63. He also deemed
    significant the prior reaction to the HPV vaccine that Petitioner reported, noting that, like Tdap,
    this vaccine contains alum as an adjuvant.
    Id. at 63.
    By contrast, Dr. Steinman discounted the fact
    that subsequent vaccines did not also cause Petitioner to relapse, claiming that the immune-
    suppressive drugs she was taking as part of her MS treatment likely protected her from an aberrant
    immune response.
    Id. at 63.
    On cross-examination, Dr. Steinman attempted to explain how what had first seemed to be
    ADEM (usually thought to be a one-time, monophasic disease) became the first symptom of MS.
    Tr. at 80. He claimed that effective treatment helped resolve Petitioner’s ADEM, and that this was
    consistent with the monophasic nature of the illness. Tr. at 71–72 (“[t]hat’s why it’s called ADEM.
    It very rarely relapses, . . .because relapsing ADEM, why isn’t that relapsing-remitting MS? It’s
    just nomenclature”). When asked if in fact ADEM was better understood to constitute a distinct
    neurologic condition from MS, Dr. Steinman explained that his overall view was to lump them
    together, and that literature supported the conclusion that ADEM was related to MS.
    Id. at 72,
    90–
    91. He also noted that ADEM could itself relapse (although the literature he cited for this
    proposition seemed to suggest that something initially viewed as ADEM, when followed by a
    symptom relapse, should in retrospect be seen as the first manifestation of MS). Tr. at 88–90; L.
    Krupp et al., International Pediatric Multiple Sclerosis Study Group Criteria for Pediatric
    Multiple Sclerosis and Immune-Mediated Central Nervous System Demyelinating Disorders:
    Revisions to the 2007 Definitions, 19 Multiple Sclerosis J. 1261, 1263 (2013), filed as Ex. C Tab
    5 (ECF No. 29-5) (“Krupp”). He also agreed that despite the above, ADEM and CIS could both
    be isolated, one-time events. Tr. at 93–94.
    Dr. Steinman was also asked how the Tdap vaccine could cause what initially appeared to
    be a one-time, acute event to evolve into a chronic condition like MS. Dr. Steinman asserted that
    the cytokine elevation occasioned by vaccination resulted in these immune cells going into the
    CNS, “and they don’t necessarily go out,” meaning future relapses became likely. Tr. at 72–73. 14
    But when asked how long this production of cytokines would continue post-vaccination, he could
    not fully answer (“I don’t think it’s been studied that carefully” (Id. at 73)), but maintained that
    the alum adjuvant itself likely “does hang around for a long time,” estimating it would take days
    or weeks to metabolize before decreasing.
    Id. at 73–74.
    He admitted, however, that even if all the
    above were accurate, other factors might trigger subsequent MS relapses—and that this topic was
    not actually addressed in the papers he cited to establish how the first flare/MS symptom would
    occur.
    Id. at 74.
    14
    Dr. Steinman also asserted that certain immune cells like macrophages might also transport alum into the brain,
    where it could contribute to cytokine upregulation. Tr. at 74.
    11
    B.      Respondent’s Expert – Dr. Jeffrey Gelfand
    Dr. Gelfand, a neurologist, testified for Respondent at hearing and also submitted two
    expert reports. Tr. at 102–54; Report, dated Mar. 30, 2018, filed as Ex. A (ECF No. 27-1) (“First
    Gelfand Rep.”); Report, dated Sept. 20, 2019, filed as Ex. D (ECF No. 42-1) (“Second Gelfand
    Rep.”). He opined that the medical record did not support the conclusion that Petitioner’s MS was
    caused by the Tdap vaccine.
    Dr. Gelfand is a board-certified neurologist currently employed as a professor of neurology
    at the University of California, San Francisco. Dr. Gelfand Curriculum Vitae, filed as Ex. F (ECF
    No. 45-1) (“Gelfand CV”) at 1. He obtained his bachelor’s degree from Princeton University
    before receiving his medical degree from Harvard University.
    Id. He then
    completed his internship
    and residency in neurology at the University of California, San Francisco.
    Id. He subsequently
    completed a fellowship in the subspecialty areas of MS and neuroimmunology.
    Id. Much of
    Dr.
    Gelfand’s clinical practice is focused on MS, neuroimmunology, and autoimmune neurology.
    Id. at 3;
    Tr. at 102. He has experience treating patients throughout all stages of MS, as well as patients
    experiencing ADEM and autoimmune encephalopathies. Tr. at 106. Beyond clinical work, Dr.
    Gelfand also conducts research and has published numerous articles on these subject areas.
    Gelfand CV at 13–22.
    Dr. Gelfand first discussed what he saw in Ms. Samuels’s medical history. Like Dr.
    Steinman, he noted that Petitioner’s initial visual symptoms presented within a day of her receipt
    of the Tdap vaccine. Tr. at 108. Those symptoms evolved into the bilateral INO diagnosis she
    received not long thereafter, and he agreed this was a proper diagnosis. Id.at 108, 110, 137. As Dr.
    Gelfand explained, INO involves injury to “a very specific pathway in the brainstem” associated
    with coordinated eye movement.
    Id. at 108–09.
    It manifests with symptoms of double/blurry vision
    and is in his view a “classic archetypal syndrome” for MS or other demyelinating diseases
    (although it can be the result of a brainstem stroke in older patients with vascular disease).
    Id. at 109.
    He also agreed with Dr. Steinman that Petitioner’s initial symptoms constituted her “first
    attack of relapsing-remitting [MS].”
    Id. at 110.
    An initial demyelinating CNS injury Dr. Gelfand opined, would properly be considered
    CIS until a second incident, and thus CIS was the best diagnostic classification under such
    circumstances (i.e., where MS was suspected but could not yet be formally diagnosed). Tr. at 116,
    133–34. He felt there was some “clinical utility” in having essentially a placeholder diagnosis for
    an initial neurologic CNS injury that warranted follow-up, allowing revision to the diagnosis
    “based on the new totality of the evidence” if the patient experienced subsequent symptoms.
    Id. at 132,
    134. The CIS designation also allowed for more precise treatment. The immunosuppressive
    therapies used for MS, he noted, posed risks, and were also not the best approaches for treating a
    one-time, acute, monophasic inflammatory/demyelinating event.
    Id. He added
    that certain CIS
    12
    presentations might be corroborated with enough additional evidence suggestive of MS (whether
    MRI or CSF findings) to allow for MS-oriented treatments earlier on.
    Id. at 133.
    Unlike Dr. Steinman, Dr. Gelfand believed there were features that distinguish ADEM
    from CIS, even if both were CNS-demyelinating afflictions. ADEM, he maintained, was medically
    understood to be “multifocal,” meaning it did not target a single place in the body, most commonly
    affected children, and was otherwise a monophasic occurrence “that typically has a component of
    encephalopathy.” Tr. at 116, 118–19. ADEM as a medical descriptor could not be interchangeably
    used to describe other common initial MS presenting symptoms, like optic neuritis.
    Id. at 117,
    143
    (“[i]f ADEM refers to a distinct pathophysiologic entity that’s monophasic and multifocal and has
    a particular phenotype, that is a different entity than what we see as the typical MS disease
    process”). Although Dr. Gelfand agreed that a person might phenotypically appear to have ADEM
    but then go on to experience a neurologic relapse (and therefore need to be diagnostically
    reclassified as suffering from MS), in “the vast majority of cases” ADEM was an acute, “one-time
    event.”
    Id. at 117.
    He therefore stressed the importance of maintaining a diagnostic distinction
    between CIS and ADEM.
    Id. at 135.
    Under the facts of this case, Dr. Gelfand maintained that CIS and not ADEM best explained
    Petitioner’s initial presentation. Tr. at 139–40. Only a very broad definition of ADEM, making it
    “synonymous with CIS,” could properly explain a first MS symptoms presentation, but he insisted
    that CIS was more precise and overall, in his view, accurate.
    Id. at 144;
    Second Gelfand Rep. at 3
    (“[t]he phenotype of a single episode of a single focus of inflammatory demyelination in the
    brainstem causing [INO] without evidence of injury to other areas of the nervous system and
    without encephalopathy supports a diagnosis of CIS and not what is generally considered under
    the ADEM diagnostic umbrella.”).
    In support, Dr. Gelfand referenced the “McDonald criteria” for diagnosing MS also
    referenced by Dr. Steinman. Tr. at 118, A. Thompson et al., Diagnosis of Multiple Sclerosis: 2017
    Revisions of the McDonald Criteria, 17 Lancet Neurology 162, 162–73 (2018), filed as Ex. C Tab
    4 (ECF No. 29-4) (“McDonald”). While INO (which the experts agree Ms. Samuels first
    experienced) is included as a kind of “focal brainstem syndrome,” and therefore a common MS
    presenting symptom, an encephalopathic reaction like ADEM was at best atypical of MS. Tr. at
    118 (referencing McDonald at 163). Dr. Gelfand agreed that even under the McDonald Criteria,
    individuals properly diagnosed as having initially experienced ADEM could also go on to
    experience MS (in which case ADEM would be the presenting symptom). Tr. at 135–36. 15 But
    despite the fact that ADEM and CIS have overlapping diagnostic features and Dr. Sloane’s reliance
    15
    Dr. Gelfand was less willing to accept that ADEM could be used as a diagnostic descriptor for a second MS
    flare/relapse. Tr. at 139.
    13
    on ADEM to explain Petitioner’s presentation, Dr. Gelfand opined that CIS was the best diagnostic
    classification for Petitioner’s initial post-vaccination symptoms.
    Id. at 137–38.
    Next, Dr. Gelfand provided some context about the nature of MS and what is known about
    its possible causes or symptom triggers. MS “leads to a proinflammatory or misdirected immune
    system against the [CNS].” Tr. at 111. It is understood to be a chronic, non-monophasic condition,
    in which an ongoing inflammatory state causes different injuries (brain and spinal cord lesions
    and/or neurodegeneration).
    Id. at 111–12.
    He noted its causes were largely not understood by
    medical science, but that MS was accepted as an autoimmune disease with “multifactorial”
    elements behind it.
    Id. at 110.
    Genetics were accepted as a risk factor, and also some specific
    environmental factors (such as certain wild virus infections like Epstein-Barr, smoking, and even
    an individual’s vitamin D levels or sunlight exposure).
    Id. at 111.
    In Dr. Gelfand’s experience
    clinically, it was rare to ever successfully identify what had specifically instigated an individual’s
    MS.
    Id. Dr. Gelfand
    specifically questioned the reliability of Dr. Steinman’s causal theory that
    cytokine upregulation could cause MS. He agreed that certain cytokines identified by Dr.
    Steinman, like IL-1β, were markers for the “active inflammatory process” that would characterize
    an existing case of MS. Tr. at 112; S. Hauser et al., Cytokine Accumulation in CSF of Multiple
    Sclerosis Patients: Frequent Detection of Interleukin-1 and Tumor Necrosis Factor but not
    Interleukin-6, 40 Neurology 1735–39 (1990), filed as Ex. 45 (ECF No. 48-4) (“Hauser”). But he
    disputed that the presence of those cytokines established their causal role in the MS process, or
    that they were specific to any particular disease. Tr. at 112–13. Hauser itself did not find the
    cytokines were causal. Hauser at 1737 (noting at best that some proinflammatory cytokines might
    either “participate” in lesion development or contribute to common MS symptoms felt during the
    disease, like fatigue). He also noted that the nature of MS did not line up well with what is known
    about cytokine propagation, post-vaccine or otherwise. The inflammation associated with MS is
    not “time-restricted to the acute attack” of the first MS presentation or any subsequent relapses,
    but is instead ongoing (as evidenced by CSF testing during a patient’s course, which will continue
    to reveal the presence of oligoclonal bands—and thus that an active inflammatory response is
    present).
    Id. at 113.
    There is no scientific explanation, Dr. Gelfand contended, for how a single vaccination
    could cause such an ongoing inflammatory milieu. Tr. at 114. Because cytokines do not have a
    long half-life, it could not be assumed that they would simply linger after their creation, but instead
    would have to be continuously replenished.
    Id. In addition,
    what medical science does know about
    MS suggests that the chronic inflammation it features is limited to/occurs within the CNS.
    Id. at 114–15
    (“the theory is that there’s an inflammatory process that takes hold and that even within
    the [CNS], there can be persistent chronic inflammation”). The chronicity of inflammation in MS
    14
    distinguishes it from acute and monophasic processes which may also involve CNS damage (and
    therefore may resemble an MS relapse).
    Id. at 115.
    Besides expressing his views on MS generally and Ms. Samuels’s presentation
    specifically, Dr. Gelfand addressed whether Tdap or any vaccine might be causal in this case. He
    disputed the existence of any scientific or medical literature associating the Tdap vaccine to Ms.
    Samuels’s INO. Tr. at 119. He maintained that more broadly, vaccination was not deemed a risk
    factor in causing MS, citing a recent review article that considered other possible environmental
    triggers but did not include vaccines in its review. Tr. at 120, D. Reich et al., Multiple Sclerosis,
    378 N. Eng. J. Med., 169–80 (2018), filed as Ex. G Tab 2 (ECF No. 46-2) (“Reich”). Reich noted
    risk factors such as gender (women more commonly experience MS) and geographic location
    (possibly associated with sunlight amounts in northern climes where MS is more prevalent), and
    listed environmental triggers like tobacco exposure, obesity, or prior exposure to the Epstein-Barr
    virus. Reich at 172–73. And even for such identified factors, “the mechanisms by which genetic
    polymorphisms and environmental exposures raise the risk of multiple sclerosis remain the subject
    of intense investigation.”
    Id. at 173.
    16
    Dr. Gelfand also referenced an epidemiologic study that specifically considered whether
    there was an association between MS and vaccination. A. Langer-Gould et al., Vaccines and the
    Risk of Multiple Sclerosis and Other Central Nervous System Demyelinating Diseases, 71 JAMA
    Neurology, 12:1506-13 (2014), filed as Ex. C Tab 8 (ECF No. 29-8) (“Langer-Gould”). Langer-
    Gould, a case-control study, specifically analyzed incident events of MS, CIS, and ADEM
    separately, comparing 780 incident cases of CNS injuries versus 3885 controls, but found no
    increased risk of ADEM or CIS in people less than age fifty with respect to all vaccines (including
    Tdap, which accounted for a large proportion of total vaccine exposures). Langer-Gould at 1511–
    12; First Gelfand Rep. at 12–13.
    Other articles reached the same conclusions. Second Gelfand Rep. at 5 (citing M. Mailand
    & J. Frederiksen, Vaccines and Multiple Sclerosis: A Systemic Review, J. Neurology 1, 1–17
    (2017), filed as Ex. G Tab 3 (ECF No. 46-3) (“Mailand”). A 2017 Systematic Review on
    vaccinations and MS risk published in the Journal of Neurology concluded that there was no
    evidence of increased risk of MS following tetanus, diphtheria, or pertussis vaccination, and the
    2012 Institute of Medicine report concluded that the evidence was inadequate to accept or reject a
    causal relationship between diphtheria-toxoid, tetanus toxoid, or acellular pertussis containing
    vaccine and onset of MS in adults. Mailand at 2; Institute of Medicine, Diphtheria Toxoid-,
    16
    Reich also suggests (contrary to the degree Petitioner’s theory relies on a sudden innate immune response in the
    aftermath of vaccination as having triggered Petitioner’s MS) that it is the adaptive arm of the immune response that
    plays a “critical” role in MS’s pathogenesis. Reich at 173.
    15
    Tetanus Toxoid-, and Acellular Pertussis-Containing Vaccines, Adverse Effects of Vaccines, 525,
    553 (2012).
    Taking the above into account, Dr. Gelfand noted that in his clinical practice he
    recommends MS patients receive routine vaccines to ward off infections that (due to
    immunosuppressive treatments they receive) could be especially harmful—and even likely to
    cause MS flares themselves. Tr. at 120–22. He did admit, however, that there was evidence that
    certain vaccines could be causal of or contribute to other demyelinating conditions.
    Id. at 131.
    In addition, Dr. Gelfand challenged Dr. Steinman’s theory that Petitioner’s short onset
    was reflective of an immune memory recall response. He particularly disputed that such a response
    would be “specific for the [CNS],” such that it would generate CNS-oriented inflammation
    sufficient to produce the kind of chronic disease process that characterizes MS. Tr. at 123. He
    agreed that some of Dr. Steinman’s arguments about the speed of tuberculin response after re-
    exposure was reliable evidence of recall as a general matter, but denied that the same kind of recall
    process could reliably explain how a subsequent exposure to Tdap components, or merely its
    adjuvant, would result in a targeted CNS attack.
    Id. at 129.
    Dr. Gelfand also addressed some of the literature referenced by Petitioner in support of
    timing and vaccine association generally. Schonberger, for example, involved GBS—a wholly
    different neuropathic injury that was known to be monophasic and acute, and therefore shed little
    light on the timing of MS’s pathogenesis.
    Id. at 123–24.
    And although he agreed that Baxter did
    observe some statistically-significant association between Tdap and ADEM, that article
    specifically excluded from consideration individuals who experienced MS, either before or after
    vaccination.
    Id. at 125–26,
    140–41; Baxter at 1457. During cross examination, Dr. Gelfand did not
    dispute that epidemiologic studies had to be structured so that they could detect rare events, but he
    denied that studies could not be aimed at determining the likelihood of MS after vaccination simply
    because the injury alleged was rare. Tr. at 141–42. In so maintaining, he noted that MS was more
    common than ADEM or TM (yet Baxter had looked at both), and that existing literature that he
    deemed reliable had not found an association between MS and the Tdap vaccine.
    Id. at 142.
    At bottom, the only association between the Tdap vaccine Petitioner received and onset
    of her MS was temporal in nature. Tr. at 126. But Dr. Gelfand proposed that a sudden onset of a
    first MS flare might only suggest that the disease process had preexisted vaccination, progressing
    in a subclinical manner over time.
    Id. at 127.
    He specifically pointed to the fact that the lesions
    observed from the initial MRIs performed on Ms. Samuels were “clinically silent,” in that they
    were distinguishable from the brainstem injury reflected in her INO symptoms.
    Id. at 130.
    Had
    these lesions only arisen post-vaccination, they should have been enhancing on imaging (which
    would reveal their active/recent character) but were not—and in fact may have preceded her
    vaccination for this reason, although he could not date them.
    Id. at 130,
    153–54. He agreed,
    16
    however, that Petitioner’s treaters had properly classified the lesions as nonspecific, and therefore
    he could not opine with certainty that they were part of her overall MS disease process, at least
    based on strict diagnostic criteria.
    Id. at 130,
    149. The presence of these lesions at the time of
    Petitioner’s first symptoms was suggestive of a longer-term problem, especially given what is now
    known about her overall course, but Dr. Gelfand agreed that her treaters were properly cautious in
    not overstating the significance of such findings (although Dr. Sloane nevertheless proposed a
    “watch and wait” approach based on all the findings together).
    Id. at 150–51.
    Dr. Gelfand could not identify what might have caused Ms. Samuels’s MS. Tr. at 147. He
    stressed his overall view that such matters remained generally scientifically unknown, and at best
    it is believed that MS has multifactorial origins.
    Id. He thus
    deemed the circumstances of the cause
    of Petitioner’s illness not much different from what causes MS for most individuals.
    Id. III. Procedural
    History
    As noted above, this case was filed in January 2017. After the gathering and filing of
    medical records was completed, Respondent submitted his Rule 4(c) Report in August of that same
    year contesting the appropriateness of compensation. ECF No. 14. The parties then began the
    process of filing expert reports, starting with Dr. Steinman’s first report in December 2017, and
    ending with a “second supplemental” report from Dr. Steinman in October 2019. In the interim
    time period, I set the matter for hearing to be held in November 2019, and the parties offered their
    prehearing filings in advance of that hearing. The hearing proceeded as scheduled, and the parties
    declined the opportunity to file post-hearing briefs, making the case now fully ripe for resolution.
    IV.      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 & Human Servs., 
    592 F.3d 1315
    , 1321 (Fed.
    Cir. 2010); Capizzano v. Sec’y of Health & Human Servs., 
    440 F.3d 1317
    , 1320 (Fed. Cir. 2006). 17
    In this case, Petitioner does not assert a Table claim.
    17
    Decisions of special masters (some of which I reference in this ruling) constitute persuasive but not binding
    authority. Hanlon v. Sec’y of Health & Human 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 & Human Servs., 
    59 Fed. Cl. 121
    ,
    17
    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 & Human 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 & Human Servs., 
    165 F.3d 1344
    ,
    1352–53 (Fed. Cir. 1999)); Pafford v. Sec’y of Health & Human 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: “(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.” Althen v.
    Sec’y of Health & Human Servs., 
    418 F.3d 1274
    , 1278 (Fed. Cir. 2005).
    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 & 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, 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
    124 (2003), aff’d 104 F. Appx. 712 (Fed. Cir. 2004); see also Spooner v. Sec’y of Health & Human Servs., No. 13-
    159V, 
    2014 WL 504728
    , at *7 n.12 (Fed. Cl. Spec. Mstr. Jan. 16, 2014).
    18
    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 v.
    Sec’y of Health & Human Servs., 
    121 Fed. Cl. 230
    , 245 (2015) (“[p]lausibility . . . in many cases
    may be enough to satisfy Althen prong one” (emphasis in original)).
    In discussing the evidentiary standard applicable to the first Althen prong, many decisions
    of the Court of Federal Claims and Federal Circuit have emphasized that petitioners need only
    establish a causation theory’s biological plausibility (and thus need not do so with preponderant
    proof). Tarsell v. United States, 
    133 Fed. Cl. 782
    , 792–93 (2017) (special master committed legal
    error by requiring petitioner to establish first Althen prong by preponderance; that standard applied
    only to second prong and petitioner’s overall burden); see also 
    Contreras, 121 Fed. Cl. at 245
    ;
    
    Andreu, 569 F.3d at 1375
    . At the same time, there is contrary authority from the Federal Circuit
    suggesting that the same preponderance standard used overall in evaluating a claimant’s success
    in a Vaccine Act claim is also applied specifically to the first Althen prong. See, e.g., Broekelschen
    v. Sec’y of Health & Human Servs., 
    618 F.3d 1339
    , 1350 (Fed. Cir. 2010) (affirming special
    master’s determination that expert “had not provided a ‘reliable medical or scientific explanation’
    sufficient to prove by a preponderance of the evidence a medical theory linking the [relevant
    vaccine to relevant injury].”) (emphasis added). Regardless, one thing remains: petitioners always
    have the ultimate burden of establishing their Vaccine Act claim overall with preponderant
    evidence. W.C. v. Sec’y of Health & Human Servs., 
    704 F.3d 1352
    , 1356 (Fed. Cir. 2013) (citations
    omitted); 
    Tarsell, 133 Fed. Cl. at 793
    (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 & 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).
    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,
    19
    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 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); Veryzer v. Sec’y of Dept. of Health & Human 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 & Human 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 &
    Human 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 & Human 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 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 & Human Servs., 
    3 F.3d 415
    , 417 (Fed. Cir. 1993) (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
    20
    events in question that was given at a later date, provided that such determination is evidenced by
    a rational determination).
    Medical records that are created contemporaneously with the events they describe are
    presumed to be accurate and “complete” (i.e., presenting all relevant information on a patient’s
    health problems). 
    Cucuras, 993 F.2d at 1528
    ; Doe/70 v. Sec’y of Health & Human 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 sub nom. Rickett v. Sec’y of Health
    & Human Servs., 468 F. Appx. 952 (Fed. Cir. 2011) (non-precedential opinion). This presumption
    is based on the linked propositions that (i) sick people visit medical professionals; (ii) sick people
    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 & Human Servs., No. 11-685V, 
    2013 WL 1880825
    , at *2 (Fed. Cl. Spec. Mstr.
    Apr. 10, 2013); Cucuras v. Sec’y of Health & Human 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 & Human Servs., No. 03-1585V, 
    2005 WL 6117475
    , at *20 (Fed. Cl. Spec. Mstr. Dec. 12, 2005). Indeed, contemporaneous medical
    records are generally 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 Dep’t of Health & Human Servs., 
    23 Cl. Ct. 726
    , 733 (1991) (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.”)).
    There are, however, situations in which compelling oral testimony may be more persuasive
    than written records, such as where records are deemed to be incomplete or inaccurate. Campbell
    v. Sec’y of Health & Human 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 & Human
    Servs., 
    991 F.2d 1570
    , 1575 (Fed. Cir. 1993).
    21
    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 & Human
    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. Lalonde v. Sec’y
    of Health & Human 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 & Human 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 Pharmaceuticals,
    Inc., 
    509 U.S. 579
    , 594–96 (1993). See Cedillo v. Sec’y of Health & Human Servs., 
    617 F.3d 1328
    ,
    1339 (Fed. Cir. 2010) (citing Terran v. Sec’y of Health & Human Servs., 
    195 F.3d 1302
    , 1316
    (Fed. Cir. 1999)). “The Daubert 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.” 
    Terran, 195 F.3d at 1316
    n.2
    (citing 
    Daubert, 509 U.S. at 592
    –95).
    The Daubert factors play a slightly different role in Vaccine Program cases than they do
    when applied in other federal judicial fora (such as the district courts). Daubert factors are usually
    employed by judges (in the performance of their evidentiary gatekeeper roles) to exclude evidence
    that is unreliable and/or could confuse a jury. In Vaccine Program cases, by contrast, these factors
    are used in the weighing of the reliability of scientific evidence proffered. Davis v. Sec’y of Health
    & Human 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
    22
    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 of his own 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, 618 F.3d at 1347
    (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. 136
    , 146 (1997));
    see also Isaac v. Sec’y of Health & Human Servs., No. 08-601V, 
    2012 WL 3609993
    , at *17 (Fed.
    Cl. Spec. Mstr. July 30, 2012), mot. for rev. denied, 
    108 Fed. Cl. 743
    (2013), aff’d, 540 F. Appx.
    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 & Human 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”).
    Expert opinions based on unsupported facts may be given relatively little weight. See
    Dobrydnev v. Sec’y of Health & Human Servs., 556 F. Appx. 976, 992–93 (Fed. Cir. 2014) (“[a]
    doctor’s conclusion is only as good as the facts upon which it is based”) (citing Brooke Group Ltd.
    v. Brown & Williamson Tobacco Corp., 
    509 U.S. 209
    , 242 (1993) (“[w]hen an expert assumes
    facts that are not supported by a preponderance of the evidence, a finder of fact may properly reject
    the expert’s opinion”)). Expert opinions that fail to address or are at odds with contemporaneous
    medical records may therefore be less persuasive than those which correspond to such records. See
    Gerami v. Sec’y of Health & Human Servs., No. 12-442V, 
    2013 WL 5998109
    , at *4 (Fed. Cl. Spec.
    Mstr. Oct. 11, 2013), aff’d, 
    127 Fed. Cl. 299
    (2014).
    D.      Consideration of Medical Literature
    Both parties filed medical and scientific literature in this case, but not every filed item
    factors 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 every individual medical
    23
    record filed. Moriarty v. Sec’y of Health & Human Servs., 
    844 F.3d 1322
    , 1328 (Fed. Cir. 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 & Human Servs., 527 F. Appx. 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.       Consideration of Comparable Special Master Decisions
    In reaching a decision in this case, I have considered other decisions issued by special
    masters (including my own) involving similar injuries, vaccines, or circumstances. I also reference
    some of those cases in this Decision, in an effort to establish common themes, as well as
    demonstrate how prior determinations impact my thinking on the present case.
    There is no error in doing so. It is certainly correct that prior decision in different cases do
    not control the outcome herein. 18 Boatmon v. Sec’y of Health & Human Servs., 
    941 F.3d 1351
    ,
    1358–59 (Fed. Cir. 2019); Hanlon v. Sec’y of Health & Human Servs., 
    40 Fed. Cl. 625
    , 630 (1998).
    Thus, the fact that another special master reasonably determined elsewhere, on the basis of facts
    not in evidence in this case, that preponderant evidence supported the conclusion that vaccine X
    caused petitioner’s injury Y does not compel me to reach the same conclusion in this case.
    Different actions present different background medical histories, different experts, and different
    items of medical literature, and therefore can reasonably result in contrary determinations.
    However, it is equally the case that special masters reasonably draw upon their experience
    in resolving Vaccine Act claims. Doe v. Sec’y of Health & Human Servs., 
    76 Fed. Cl. 328
    , 338–
    39 (2007) (“[o]ne reason that proceedings are more expeditious in the hands of special masters is
    that the special masters have the expertise and experience to know the type of information that is
    most probative of a claim”) (emphasis added). They would therefore be remiss in ignoring prior
    cases presenting similar theories or factual circumstances, along with the reasoning employed in
    reaching such decisions. This is especially so given that special masters not only routinely hear
    from the same experts in comparable cases, but are also repeatedly offered the same items of
    medical literature regarding certain common causation theories. It defies reason and logic to
    obligate special masters to “reinvent the wheel”, so to speak, in each new case before them, paying
    no heed at all to how their colleagues past and present have addressed similar causation theories
    18
    By contrast, Federal Circuit rulings concerning legal issues are binding on special masters. Guillory v. Sec’y of
    Health & Human Servs., 
    59 Fed. Cl. 121
    , 124 (2003), aff’d 104 F. Appx. 712 (Fed. Cir. 2004); see also Spooner v.
    Sec’y of Health & Human Servs., No. 13-159V, 
    2014 WL 504728
    , at *7 n.12 (Fed. Cl. Spec. Mstr. Jan. 16, 2014).
    Special masters are also bound within a specific case by determinations made by judges of the Court of Federal Claims
    after a motion for review is resolved.
    24
    or fact patterns. It is for this reason that prior decisions can have high persuasive value—and why
    special masters often explain how a new determination relates to such past decisions. 19 Even if the
    Federal Circuit does not require special masters to distinguish other relevant cases 
    (Boatmon, 941 F.3d at 1358
    ), it is still wise to do so.
    ANALYSIS
    I.       Overview of ADEM, MS, and Their Overlapping Features
    On several prior occasions, I have considered the relationship between ADEM and MS in
    resolving a Vaccine Act claim. See, e.g., Taylor v. Sec’y of Health & Human Servs., No. 13-700V,
    
    2018 WL 2050857
    , at *20–21 (Fed. Cl. Spec. Mstr. Mar. 9, 2018) (comparing the diagnoses of
    ADEM and MS). In short, reliable science supports the conclusion that ADEM is best understood
    as an acute and monophasic CNS demyelinating illness that does not recur. National Multiple
    Sclerosis      Society,        Acute        Disseminated        Encephalomyelitis        (ADEM),
    https://www.nationalmssociety.org/What-is-MS/Related-Conditions/Acute-Disseminated-
    Encephalomyelitis-(ADEM) (last visited Apr. 9, 2020), filed as Ex. 31 (ECF No. 30-4). Consistent
    with the testimony of Drs. Steinman and Gelfand, ADEM more often than not afflicts children,
    generally does not repeat, and often has encephalopathic features like fever, headache, confusion,
    vomiting, and seizures.
    Id. Consistent with
    its sudden appearance and fast disease course, ADEM has been found to
    be an injury that can be vaccine-caused. Brown v. Sec’y of Health & Human Servs., No. 09-426V,
    
    2011 WL 5029865
    , at *45 (Fed. Cl. Spec. Mstr. Sept. 30, 2011); Kuperus v. Sec’y of Health &
    Human Servs., No. 01-060V, 
    2003 WL 22912885
    , at *11 (Fed. Cl. Spec. Mstr. Oct. 23, 2003). The
    very immune-stimulating effects of different vaccines can theoretically cause a sudden
    autoimmune attack on CNS myelin, resulting in a demyelinating injury. Brown, 
    2011 WL 5029865
    , at *45. 20 However, not all such claimants have succeeded—especially when onset
    19
    Consideration of prior determinations is a two-way street that does not only inure to the benefit of one party. Thus,
    I would likely take into account the numerous decisions finding no association between vaccination and autism when
    confronted with a new claim asserting autism as an injury and have informed such claimants early in the life of their
    case that the claim was not viable for just that reason. But I would also deem a non-Table claim asserting GBS after
    receipt of the flu vaccine as not requiring extensive proof on Althen prong one “can cause” matters, for the simple
    reason that the Program has repeatedly litigated the issue in favor of petitioners.
    20
    Such successful cases also frequently rely, in large or small part, on what is known about how the immune system
    can play a role in causing peripheral nerve injuries, such as GBS. See, e.g., Stewart v. Sec’y of Health & Human
    Servs., No. 06-777, 
    2011 WL 3241585
    , at *16–18, 21 (Fed. Cl. Spec. Mstr. July 8, 2011) (discussing the scientific
    and medical theories for how vaccines can cause GBS).
    25
    appeared too sudden. Orloski v. Sec’y of Health & Human Servs., No. 17-936V, 
    2019 WL 7565495
    , at *15 (Fed. Cl. Spec. Mstr. Oct. 31, 2019) (immediate onset of alleged Tdap/influenza
    vaccine-caused ADEM too short, in light of literature suggesting a median onset of two weeks for
    comparable demyelinating diseases).
    MS, by contrast, is qualitatively different, despite the fact that it too involves CNS
    demyelinating injuries and is believed to be autoimmune in mechanism. MS is a chronic disease
    process that, regardless of its initial presentation, will recur and/or in severe cases progress. Krupp
    at 1263. In addition, MS can be subclinical and symptomatically silent for a long period of time,
    with MS-characteristic brain lesions often discovered in the absence of symptoms, or non-recent
    lesions discovered only after clinical manifestations. See McDonald at 163; Reich at 176. And
    significantly (and of course independent of the burden of proof petitioners bear in Program cases),
    there is little to no direct scientific knowledge as to why MS recurs—and no similar evidence that
    a one-time neurologic “hit” can produce subsequent symptoms months or years later. Tr. at 74; J.
    Gelfand, Risk of Multiple Sclerosis After a Clinically Isolated Syndrome: From Magnetic
    Resonance Imaging to Oligoclonal Bands to Activated T Cells, 74 JAMA Neurology 262, 262
    (2017), filed as Ex. C Tab 3 (ECF No. 29-3).
    Because of the above, special masters have denied compensation in cases alleging MS as
    a vaccine-caused injury despite the overlap between ADEM, TM, and MS. See, e.g., Hunt v. Sec’y
    of Health & Human Servs., No. 12-232V, 
    2015 WL 1263356
    , *15 (Fed. Cl. Spec. Mstr. Feb. 23,
    2015) (denying entitlement where MS was the alleged injury, but the literature offered discussed
    causal relationship between vaccines and ADEM). Admittedly, some special masters have gone in
    the opposite direction, and granted compensation in MS cases—but my review of those decisions
    does not reveal any reasoned efforts to grapple with the distinctions explored above. See, e.g., Hitt
    v. Sec’y of Health & Human Servs., No. 15-1283V, 
    2020 WL 831822
    , at *9–10 (Fed. Cl. Spec.
    Mstr. Jan. 24, 2020). Rather, their assumption appears to have been that if a vaccine can cause one
    kind of CNS autoimmune demyelinating injury, it can cause another.
    II.    Petitioner Has Not Preponderantly Established the Tdap Vaccine Could or
    Did Injure Her
    A.      Petitioner’s Initial Symptoms are Best Characterized as CIS Rather than ADEM
    In many cases, the first step in deciding a claim is to determine the nature of the petitioner’s
    injury—especially if the causal theory is dependent on establishing that a specific injury occurred.
    
    Broekelschen, 618 F.3d at 1345
    ; LaPierre v. Sec’y of Health & Human Servs., No. 17-227V, 
    2019 WL 6490730
    , at *16–17 (Fed. Cl. Spec. Mstr. Oct. 18, 2019). Here, the parties agree that Ms.
    Samuels suffers from MS, but that diagnostic determination could not be made until 2019—well
    26
    after the claim was filed. This placed Petitioner’s overall post-vaccination symptoms in a new
    light, and forced her to recast her claim somewhat—from one arguing that her initial symptoms
    were an acute, one-time event (ADEM), to contending that her subsequent MS only presented as
    ADEM.
    Overall, this is not a case where defining the injury is key to its resolution. Petitioner not
    only does not dispute her MS diagnosis, but alleges that the Tdap vaccine was ultimately
    responsible for her injuries, however her initial presentation is defined. But the parties nevertheless
    dispute the best diagnostic classification for Petitioner’s initial symptoms, and their disagreement
    on this topic has some significance, since ADEM is often deemed a compensable vaccine injury.
    I find that the record and expert testimony best supports CIS, rather than ADEM, as the proper
    descriptor of Petitioner’s presenting symptoms.
    Dr. Gelfand persuasively established that there are meaningful clinical and diagnostic
    differences between ADEM and CIS. Even if ADEM is a type of CNS demyelinating injury, and
    even if it can constitute an initial MS “flare,” from a medical/scientific standpoint it is better
    understood as a narrower condition in most cases than Dr. Steinman allowed, with symptoms
    specific to it that are distinguishable from a first MS presentation. Treatment implications also
    make CIS a better “placeholder” term for what might later become MS. Indeed, Petitioner’s own
    medical history reveals that her treaters not only suspected MS right away and anticipated the
    possibility of an eventual MS diagnosis, but adopted a watch-and-wait approach with her over the
    four-plus years that transpired between flares. In addition, Ms. Samuels’s presenting symptom of
    INO does appear to be common in MS, but was not shown by Petitioner to be as reasonably
    understood to be a feature of ADEM. Dr. Steinman’s ADEM definition was otherwise too broad
    to be diagnostically meaningful.
    It is correct that the medical history establishes that treaters like Dr. Sloane have
    characterized Petitioner’s initial symptoms as ADEM, even in the face of the subsequent MS
    diagnosis. But (putting aside that I need not accept as sacrosanct any treater view) this does not
    alter the fact that however initially characterized, Petitioner’s ultimate, correct diagnosis was not
    ADEM, at least as it is commonly understood as a monophasic and acute demyelinating injury—
    and thus Petitioner needed to preponderantly demonstrate that the Tdap vaccine was responsible
    for her overall disease course. 21 She did not (and I address the Althen prongs below, in order of
    their significance to my determination).
    21
    I note that Petitioner did not advance the theory that her vaccine-caused injury was only ADEM, and that her
    subsequent MS was unrelated.
    27
    B.      The Althen Prongs Have not Been Met in This Case
    1.      Althen Prong One
    Petitioner was unable to preponderantly establish that the Tdap vaccine can cause MS.
    First, as discussed above, reliable scientific evidence does not support the conclusion that any
    vaccine is associated with MS, including Tdap. See generally Reich, Langer-Gould. Articles that
    seem to support a contrary view, like Baxter, do not consider MS at all, and even only weakly
    support the conclusion that the Tdap vaccine is associated with ADEM (which I do not otherwise
    find Petitioner had, at least in its most commonly-understood sense). Thus, what evidence that was
    offered regarding vaccines, and Tdap specifically, did not support Petitioner’s causation theory.
    Second, the mechanism Petitioner embraces—generalized inflammation promoted by an
    innate immune response to the Tdap vaccine’s adjuvant, alum—is not scientifically/medically
    reliable. The literature filed by Petitioner, such as Hauser, at best establishes that cytokines are
    present or involved in an ongoing MS disease process—not that they instigate it, or can
    independently maintain it over a lengthy timeframe. There is far too little known about MS to
    conclude that the expected immune response to a vaccine could quickly inflict the kind of
    neurologic harm ultimately associated with MS well down the road. Here, the chronic nature of
    MS becomes especially important. Even if a vaccine’s upregulation of cytokines could produce a
    one-time injury to the CNS, such as ADEM or TM, how this becomes chronic later was wholly
    unexplained by Petitioner. And the central role the Tdap adjuvant is alleged to play in all of the
    above was also not adequately elucidated. Indeed, despite Dr. Steinman’s protestations to the
    contrary, the theory he embraced about the pathologic impact of an adjuvant is dangerously close
    to the discredited ASIA theory, which assumes that alum lingers in the body for long periods of
    time and causes subsequent harm simply due to its presence. Yalacki, 
    2019 WL 1061429
    , at *24
    n.30.
    Dr. Steinman’s inconsistent treatment of ADEM herein illustrates the deficiencies in
    Petitioner’ causation theory. On the one hand, he correctly noted that ADEM overlaps substantially
    with MS—both are autoimmune-mediated conditions that impact the CNS and have common
    initial presenting symptoms—as well as that MS can, in effect, be initially “mistaken” as ADEM
    (since MS can only be suspected as of the first evidence of symptoms—it cannot be diagnosed
    until a second flare or relapse occurs). But does this make ADEM and MS equivalent? No, by Dr.
    Steinman’s admission, since ADEM is most commonly a one-time, non-recurring event. Tr. at 93–
    94. Indeed, the literature filed in this case better supports the conclusion that ADEM should be so-
    considered—not that ADEM is simply a term that can flexibly be applied to the first MS symptom,
    interchangeable with CIS.
    28
    Another important distinction between ADEM and MS that Dr. Steinman unsuccessfully
    elided is the temporal character of each. ADEM is generally acute and monophasic, while MS is
    chronic. As a result, the causation theory in this case needed to explain how an initial and quite-
    acute neurologic attack could initially be mediated by a vaccine, later becoming an ever-present
    risk for Petitioner that would manifest in a new attack several years later. How would this occur?
    Would the pathologic effects of initial cytokine upregulation remain constant? Or did they injure
    the CNS in such a way that future disease progression was likely? Cases alleging different injuries
    or theories in the Program have successfully answered these questions in connection with different
    injuries, like seizure disorders. See, e.g., Silverio v. Sec’y of Health & Human Servs., No. 15-235V,
    
    2019 WL 6694020
    , at *28–30 (Fed. Cl. Spec. Mstr. Nov. 14, 2019) (varicella and pneumococcal
    conjugate vaccinations triggered fever in infant, which in turn caused a complex febrile seizure
    and subsequent epileptic seizures and disorders). But Dr. Steinman, by his admission, could not
    do the same here.
    The fact that ADEM and MS overlap in some respects does not mean that their differences
    are negligible for purposes of determining entitlement herein. Indeed, their distinguishing
    characteristics are very important in this context. Special masters have often found that vaccines
    might instigate one-time, acute events in short order, such as GBS, that in turn could have
    significant lifelong sequelae—but which do not themselves progress. However, the possibility a
    vaccine can instigate an ever-present chronic process depends heavily on evidence that the initial
    harm itself “turns on” such a process. That evidence is lacking here, as there is little to no reliable
    scientific evidence filed in this case supportive of the conclusion that the first neurologic CNS
    injury that looks like MS will more likely than not create the conditions for a second flare—or
    how this would occur.
    2.       Althen Prong Three
    Dr. Steinman agreed that Petitioner’s INO (the presenting symptom of her alleged vaccine
    injury) began within twenty-four hours of receipt of the Tdap vaccine. This was entirely too short
    a timeframe to be medically acceptable, for several reasons.
    First, the record does not suggest that proinflammatory cytokines upregulated by a vaccine
    could begin to cause autoimmune-mediated demyelinating injuries manifesting as INO in such a
    short timeframe. The fact that vaccines can initially (due to adjuvants) cause cytokines to increase
    does not also mean they become pathologic in that same time period. Dr. Steinman’s say-so to the
    contrary was not persuasive, nor was his reliance on disparate circumstances like the short
    timeframe in which GBS (a peripheral neuropathy featuring acute and monophasic demyelination)
    might manifest post-vaccination. 22 He could not credibly demonstrate how a vaccine administered
    22
    Dr. Steinman cited Schonberger for this proposition—an item of literature invoked in virtually any case where a
    petitioner hopes to prove a vaccine caused an autoimmune demyelinating injury. See, e.g., McKown v. Sec’y of Health
    & Human Servs., No. 15-1451V, 
    2019 WL 4072113
    , at *55 (Fed. Cl. Spec. Mstr. July 15, 2019) (discussing the
    29
    in the periphery of the body could result in a brainstem injury, manifesting initially as INO, within
    a day’s time.
    Second, Petitioner did not persuasively establish that even if the Tdap vaccine had
    instigated an immediate demyelinating injury sufficient to manifest as INO or ADEM, that this
    process would then become sufficiently chronic such that four years later a second flare would
    occur, revealing that Petitioner had MS the entire time. Dr. Steinman was particularly conclusory
    in setting forth this aspect of his opinion, focusing on the locus of CNS inflammation but assuming
    without much explanation that whatever process the vaccine started would continue to smolder in
    the brain for years thereafter. No persuasive showing, arising from reliable evidence, was made
    explaining how a single vaccination could trigger such a lengthy and persistent process. It is not
    enough to simply invoke the fact that vaccine injuries are rare, or that “some” unknown factor
    specific to a petitioner likely contributed to the situation, to make up for the absence of reliable
    explanatory scientific or medical evidence.
    3.       Althen Prong Two
    Petitioner in this case can unquestionably point to treater support for her claim, both for
    her favored presenting diagnosis (ADEM) as well as the purported association of her vaccination
    to the injury (not to mention the temporal relationship between vaccine and initial symptoms). But
    I am not obligated to blindly accept treater views—and I note that the overall medical record
    preponderantly establishes her actual injury was MS, an illness far less associated with vaccination
    than one-time acute CNS demyelinating events, like ADEM or TM. That same record also
    unquestionably reveals that the same treaters early on recognized that Petitioner might actually
    have MS (corroborated by findings such as the oligoclonal band test results 23), and in response
    adopted a watchful waiting treatment approach that unfortunately proved prescient. Dr. Steinman
    himself agreed that he too would have suspected MS, based on Petitioner’s clinical presentation.
    irrelevance of Schonberger where the alleged injury and vaccine differ from those discussed in the study).
    Schonberger, however, addresses only GBS, a peripheral neuropathy known to be mediated by autoantibodies, and
    thus reflects an aberrant adaptive immune response (whereas in this case Dr. Steinman’s theory is that Petitioner’s
    INO was the product not of an autoimmune cross-reaction, but attributable to cytokines generated in an innate immune
    response). In addition, the early-onset cases of GBS observed within one to three days of vaccination were not
    characterized by Schonberger’s authors as vaccine-attributable. Schonberger at 110–12 and Figure 5. As a result, the
    fact that some cases of GBS began so quickly says nothing about whether Petitioner’s twenty-four-hour post-
    vaccination onset was itself medically reasonable.
    23
    Both experts also found somewhat significant the lesions observed from Petitioner’s first MRI as possible proof that
    her disease process predated her INO symptoms (hence allowing for the inference that her MS process was subclinical
    at the time of vaccination). However, Drs. Steinman and Gelfand also seemed to agree with initial treater assessments
    that the lesions were nonspecific to Petitioner’s diagnosis, and Dr. Gelfand admitted they did not explain her INO
    (since the lesions were not found on her brainstem). I accordingly do not give these particular findings significant
    weight in my overall analysis, other than to note that they weakly support the inference that Petitioner’s MS processes
    could have predated vaccination.
    30
    Tr. at 84. Thus, although Petitioner was able to marshal some facts from the record on this
    particular prong to suggest that the Tdap vaccine “did cause” her initial INO, the weight of
    evidence overall does not support that conclusion.
    To be clear—I do not find herein that Petitioner carried her Althen prong two burden, but
    rather that she offered some reliable support favoring this component of her claim, such as Dr.
    Sloane’s opinion. The record ultimately better supports the conclusion that her presenting INO
    symptoms were not vaccine-caused, were not part of a post-vaccine, one-time monophasic event,
    and more likely reflected a disease process that could have begun prior to vaccination. There was
    also nothing in the record corroborating the contention that an innate immune response caused the
    INO symptoms, whether in the form of a test result revealing systemic inflammation elsewhere or
    some other symptom of cytokine reaction, like a fever.
    CONCLUSION
    Ms. Samuels was a highly sympathetic and credible witness, and I have no doubt she has
    suffered greatly with her disease. She is to be commended for her resilience in grappling with its
    deleterious effects, as well as in seeking an explanation for why she experienced it at all. But the
    evidence submitted in this case does not allow me to conclude that the Tdap vaccine could initiate
    a chronic disease process later resulting in MS—however the initial symptoms are defined—or
    that such a process could begin so close-in-time to vaccination. I therefore cannot decide
    entitlement in her favor.
    In the absence of a timely-filed motion for review (see Appendix B to the Rules of the
    Court), the Clerk shall enter judgment in accord with this decision. 24
    IT IS SO ORDERED.
    s/Brian H. Corcoran
    Brian H. Corcoran
    Chief Special Master
    24
    Pursuant to Vaccine Rule 11(a), the parties may expedite entry of judgment by filing a joint notice renouncing their
    right to seek review.
    31