Court Opinion

ID: 4235781
Source: CourtListenerOpinion
Date Created: 2018-01-10 21:04:11.885712+00
Date Added: 2024-06-11T09:24:08.392677
License: Public Domain

In the United States Court of Federal Claims
                                    No. 12-312V
                               Filed: August 8, 2017
                    Re-issued for Publication: January 10, 20181
       * * * * * * * * * * * * * * * * **
                                             *
    K.L.,                                    *
                                             *
                    Petitioner,              *   Vaccine Act; HPV Vaccine; Special
              v.                             *   Master; Althen v. Secretary of Health
                                             *   and Human Services; Due Process;
    SECRETARY OF THE DEPARTMENT              *   Expert Testimony; Vaccine Rule 3;
    OF HEALTH AND HUMAN                      *   Vaccine Rule 8.
    SERVICES,                                *
                    Respondent.              *
                                             *
       * * * * * * * * * * * * * * * * **

Paul S. Dannenberg, Huntington, Vermont for petitioner.

Robert P. Coleman, III, Torts Branch, Civil Division, United States Department of Justice,
Washington, D.C. for Respondent. With him were Chad A. Readler, Acting Assistant
Attorney General, Catherine E. Reeves, Deputy Director, Alexis B. Babcock, Assistant
Director, Torts Branch, Civil Division.

                                      OPINION

HORN, J.

       On May 11, 2012 petitioner K.L.2 filed a timely petition for compensation with the
National Vaccine Injury Compensation Program, under the National Childhood Vaccine
Injury Act of 1986, 42 U.S.C. §§ 300aa-1 to -34 (2012) (Vaccine Act). On March 17, 2017,

1 This opinion was issued under seal on August 8, 2017. The parties did not propose
redactions to the August 8, 2017 opinion, thus, the court issues the decision without
redactions for public distribution.
2Pursuant to an August 10, 2016 Order filed by Special Master Brian H. Corcoran,
petitioner’s name was redacted at her request in order to protect her privacy.
Special Master Brian H. Corcoran3 of the United States Court of Federal Claims denied
petitioner’s claim for an award of compensation, finding that the weight of evidence was
insufficient to support petitioner’s causation theory. See K.L. v. Sec’y of Health & Human
Servs., No. 12-0312V, 2017 WL 1713110, at *17 (Fed. Cl. Spec. Mstr. March 17, 2017).
Subsequently, on April 16, 2017, petitioner moved this court to review the Special
Master’s decision to deny her claim, pursuant to Rule 23 of the Vaccine Rules of the
United States Court of Federal Claims (RCFC) Appendix B (2017). This case comes to
the court upon that motion.

                                   FINDINGS OF FACT

         Petitioner K.L. was born on March 25, 1993. Petitioner alleges that she was healthy
prior to receiving a third dose of the human papillomavirus (HPV) vaccine Gardasil on
February 9, 2010. The record before the court indicates that K.L. was healthy during her
childhood, with the exceptions of recurring otitis media,4 anxiety disorder, reading
difficulties, and one instance of vasovagal attack with syncope.5 Regarding K.L.’s family
history, according to notes in K.L.’s medical records taken on March 22, 2010 by K.L.’s
physician, Dr. Melissa Volansky, and reconfirmed in notes taken on June 2, 2010 by
Dr. Annapurna Poduri, another of K.L.’s treating physicians, K.L. has some family history
of seizures, including three paternal cousins, one of whom had a formal epilepsy
diagnosis. Dr. Volansky’s March 22, 2010 notes further indicate that K.L.’s father once
had a seizure after sleep deprivation.

        K.L. received doses of Gardasil on May 18, 2009, August 18, 2009, and February
9, 2010. K.L. does not allege any injury or adverse effects from either of the first two
doses. On February 11, 2010, two days after she received the third dose of Gardasil, K.L.
was hospitalized after suffering a seizure. According to petitioner’s hospital record, before
the seizure, K.L’s mother witnessed K.L.’s right hand twitching, and then, within minutes,
K.L. slumped against a cabinet and hit her head on a door handle. Her mother then helped
her to the floor where K.L. “had foaming at the mouth, was biting her tongue, and was
somewhat blue around the mouth” for approximately four minutes, after which she was
conscious, but disoriented. K.L. was taken via ambulance to the Emergency Room (ER)
of Copley Hospital in Morrisville, Vermont. K.L. complained of headaches at the ER, but
according to ER records, testing indicated she had no fever, respiratory distress, or other
underlying or concurrent symptoms. K.L.’s head and neck computed tomography (CT)

3 The case originally was assigned to Special Master Christian J. Moran and transferred
to Special Master Corcoran on April 2, 2014.
4Otitis media is defined as “inflammation of the middle ear.” Dorland’s Illustrated Medical
Dictionary 1351 (32nd ed. 2012).
5Vasovagal syncope is defined as “a transient vascular and neurogenic reaction marked
by pallor, nausea, sweating, bradycardia, and rapid fall in arterial blood pressure which,
when below a critical level, results in loss of consciousness and characteristic
electroencephalographic changes.” Dorland’s Illustrated Medical Dictionary 1818.

                                             2
scan, complete blood count (CBC), and electrocardiogram (EKG) tests also were normal.
K.L.’s hospital records show her mother told ER physicians that before the seizure, K.L.
had been experiencing ear pain and had taken Benadryl and Sudafed for a recent cold.

        On the same day, K.L. was transferred to the Fletcher Allen Health Care facility at
the Vermont Children’s Hospital (FAHC), where she was admitted to the Pediatric
Intensive Care Unit (PICU), sedated and intubated. At FAHC, K.L. had a lumbar puncture
to test her cerebrospinal fluid (CSF) for indications of a central nervous system infection,
which was negative. K.L. also had a magnetic resonance imaging test (MRI), which was
normal, and an electroencephalogram (EEG),6 which indicated an impaired arousal
mechanism, but no epileptiform features.7

        On February 13, 2010, K.L. had her intubation tube removed and regained
consciousness, and was then transferred out of the PICU and discharged from Vermont
Children’s Hospital. Upon discharge, K.L. was given a diagnosis of “Single Seizure – right
body onset, mild [T]odd’s paralysis of right face.” Notes in her patient record indicate that
“[a]t transfer the cause of her seizure was thought to be multifactorial with potential
contributors including a mild URI [upper respiratory infection], OTC [over the counter]
pharmacotherapy with benadryl and sudafed, and recent HPV vaccine administration.”

       On February 15, 2010, K.L. had a follow-up appointment with Dr. Volansky who
noted K.L. complained of headaches, vomiting, nausea, and dizziness. Dr. Volansky also
noted that K.L.’s recent seizure was caused by an “unclear etiology, may have been new
onset epilepsy, may have been effect of recent Gardasil and/or decongestants.” She
confirmed K.L.’s prior imaging test results showed no sign of infection or brain trauma.

       On February 27, 2010, K.L. exhibited pre-seizure symptoms of twitching, arm
jerking and leg buckling, and she was admitted to FAHC, where she experienced a
seizure that was treated with 1000 mg of Keppra 8 and lorazepam.9 Notes from this visit
6 An electroencephalogram is defined as “a recording of the potentials on the skull
generated by currents emanating spontaneously from nerve cells in the brain . . . .
Fluctuations in potential are seen in the form of waves, which correlate well with different
neurologic conditions and so are used as diagnostic criteria.” Dorland’s Illustrated Medical
Dictionary 600.
7  Epileptiform is defined as “resembling epilepsy or its manifestations.” Dorland’s
Illustrated Medical Dictionary 633.
8 Keppra is defined as a “trademark for a preparation of levetiracetam,” which is “an
anticonvulsant administered orally as an adjunct in the treatment of partial and myoclonic
seizures and idiopathic generalized epilepsy.” Dorland’s Illustrated Medical Dictionary
979, 1031.
9 Lorazepam is defined as “a benzodiazepine with anxiolytic and sedative effects,
administered orally in the treatment of anxiety disorders and short-term relief of anxiety
symptoms.” Dorland’s Illustrated Medical Dictionary 1074.

                                             3
indicate this was her first seizure since the February 11, 2010 hospitalization, and that
she had a stomach illness a few days before. On February 28, 2010, K.L. was discharged
and instructed to take 500 mg doses of Keppra and to consult a pediatric neurologist.

       On March 22, 2010, Dr. Louisa Kalsner, a pediatric neurologist in Burlington,
Vermont, evaluated K.L.’s condition. In her report, Dr. Kalsner noted that K.L. had
experienced no seizures since February 27, 2010, was having some difficulty using her
right hand and recalling words, and complained she had been having headaches since
her third dose of Gardasil. Dr. Kalsner prescribed K.L. Ativan10 and recommended that
she increase her Keppra dosage to 750 mg twice daily.

        On June 1, 2010, K.L. had an appointment with Dr. Poduri, a neurologist and
epileptologist11 at the Boston Children’s Hospital, who reviewed K.L.’s medical records
and symptoms, and who noted that K.L. had complained of a stomach illness and had
received a Gardasil vaccination two days prior to her first seizure. At this visit, K.L.
informed Dr. Poduri that she had experienced a dead feeling in her right arm after
throwing a baseball or while after writing before her third Gardasil vaccination. Dr. Poduri
also noted that based on anecdotes K.L. related during their appointment, K.L. may have
had episodes of hand-twitching similar to her February 11, 2010 seizure “in the past,” as
well as other seizure symptoms, and Dr. Poduri wrote “there is certainly the possibility
that she has had some sensory only seizures as well.” Based on her examination, K.L.’s
family history, and the association between epilepsy and a certain brain abnormality and
reading difficulties at K.L.’s age, Dr. Poduri determined that K.L. had a juvenile onset form
of idiopathic partial onset epilepsy.12 She noted this was “the most likely diagnosis given
her otherwise normal developmental history and her normal examination.” Dr. Poduri’s
notes do not indicate a diagnostic connection between the seizures and Gardasil. She
also recommended that K.L. have a more detailed MRI for additional evaluation.

        On June 22, 2010, K.L. had a follow-up appointment with Dr. Kalsner, who noted
that K.L. was responding well to the Keppra and had experienced no seizures since
February. Dr. Kalsner noted that “[t]here was some concern about having Gardasil
vaccination, third dose, 2 days prior to having her first seizure onset and maybe that
indicates seizures should improve; however, would continue antiseizure medication for a
total duration of 2 years and then gradually try to taper it off.” Her notes gave no indication
as to whether she agreed or disagreed with a Gardasil-related theory. She recommended

10 Ativan is defined as “a trademark for preparations of lorazepam,” defined in the
preceding footnote. Dorland’s Illustrated Medical Dictionary 173.
11Epileptologist is defined as “a specialist in the study, diagnosis, and treatment of
epilepsy.” Dorland’s Illustrated Medical Dictionary 634.
12Idiopathic epilepsy is defined as “epilepsy of unknown origin, possibly associated with
some inherited predisposition for seizures.” Dorland’s Illustrated Medical Dictionary 633.

                                              4
a follow-up visit at the neurology clinic in six months. Dr. Kalsner was aware of K.L.’s prior
evaluation by an epileptologist, but had not received a record of Dr. Poduri’s evaluation.

       On June 30, 2010, Dr. Poduri performed and reviewed the results of the more
detailed MRI she had recommended and found no brain abnormalities. Thereafter, she
diagnosed K.L. with “partial-onset epilepsy that appears to be truly idiopathic.”

       In the following months, records from K.L.’s visits with her physicians on July 27,
2011, August 11, 2011, and January 19, 2012 indicate that although K.L. did not have
any additional seizures, she suffered from frequent headaches and vomiting, which was
controlled by migraine medication, and from functional dyspepsia13 and gastroparesis,14
which improved after she eliminated dairy from her diet. On January 9, 2012, K.L. had a
comprehensive educational evaluation because of difficulties she was having in college,
and was diagnosed with a language-based disorder of written expression. She was
advised to obtain a tutor and reduce her course load, and also began to see a psychiatrist
and take antidepressants to reduce her anxiety.

       On May 4, 2012, Dr. Kalsner recommended that K.L. reduce her Keppra
medication to 500 mg twice a day, because she thought it “might help with her symptoms
of anxiety and difficulty with sleep.” The record indicates that K.L. informed Dr. Katherine
A. Wayman, a physician who evaluated K.L. at FAHC on January 29, 2013, that she had
reduced her Keppra dosage to 500 mg “around September.” K.L. reported to Dr. Wayman
that “about [one] week ago” she had started having partial seizures every few minutes, in
the form of twitching in various places on her body. To control them, Dr. Wayman
prescribed her Ativan for five days and advised K.L. to return to the higher dose of Keppra,
750 mg twice a day, which controlled her seizures.

        On May 11, 2012, petitioner filed her timely petition for compensation under the
Vaccine Act in the United States Court of Federal Claims, Office of Special Masters, and
her case was assigned to Special Master Christian J. Moran. Because the petition was
filed without all the statutorily required supporting medical records, see 42 U.S.C. §
300aa-11(c), petitioner twice requested, and Special Master Moran granted, extensions
of time for petitioner to file all the necessary medical records. On October 26, 2012,
petitioner filed some of the missing records and a statement of completion. On November
26, 2012, respondent submitted a status report regarding the lack of completeness of
petitioner’s medical records filed to date, and noted a number of remaining deficiencies.

13 Functional dyspepsia is defined as “dyspepsia with no physical cause, usually resulting
from nervousness or anxiety; it can have serious manifestations, resembling the
symptoms of peptic ulcer, although no ulcer is detectable.” Dorland’s Illustrated Medical
Dictionary 579.
14Gastroparesis is defined as “paralysis of the stomach, usually from damage to its nerve
supply, so that food empties out much more slowly, if at all. Symptoms include early
satiety, nausea, and vomiting.” Dorland’s Illustrated Medical Dictionary 765.

                                              5
         The parties had a status conference on December 11, 2012. On the same date,
Special Master Moran issued an Order for petitioner to file the remaining required medical
records and an amended petition “clearly stating the alleged injury or injuries caused by
her . . . vaccinations.” On January 25, 2013, petitioner filed notice of her intent to continue
her petition because the statutory 240-day time period for the Special Master’s issuance
of a decision had lapsed. See Vaccine Rule 10(b). Pursuant to the December 11, 2012
Order and an April 12, 2013 Order, petitioner filed an amended petition and additional
medical records.

        On June 10, 2013, respondent filed a Report pursuant to Vaccine Rule 4(c), the
due date for which had been suspended up to this point pending petitioner’s filing of
complete medical records. Respondent argued that compensation was not appropriate
under the terms of the Vaccine Act, since petitioner had not met her burden of proof.
Respondent argued that, because petitioner was alleging non-Table injuries from the
Gardasil vaccination, she was required to demonstrate, by a preponderance of the
evidence, that her injuries were caused-in-fact by the vaccine. Respondent further argued
that no compensation should be awarded because (1) petitioner had failed to offer a
reputable scientific or medical theory that Gardasil could or did cause epilepsy or
migraines, (2) that a merely “possible” causal link between the vaccination and injury is
insufficient to meet petitioner’s burden under the Vaccine Act, and (3) that temporal
proximity alone is insufficient to prove causation.

       On December 23, 2013, Special Master Moran issued a draft Order regarding the
parties’ proposed expert witnesses, instructing the parties that “the expectation is that the
expert’s written report will constitute the expert’s direct testimony,” in lieu of offering direct
testimony at trial, and allowing the parties until January 10, 2014 to file any response.
Neither party filed an objection. The draft Order was discussed further at a status
conference held on January 15, 2014, at which Special Master Moran “reminded the
parties” that after the expert reports were filed, “further direct testimony from their experts
should not be expected at hearing.” At the January 15, 2014 conference, once again,
neither party objected. Also on January 15, 2014, Special Master Moran issued a final
version of the draft Order and an “Order Regarding Expert Reports,” which described “the
minimum information necessary from the expert,” along with an Order directing that the
parties’ “expert’s report will constitute that expert’s direct testimony.” Finally, given the
multiple extensions already given to petitioner and her counsel, Special Master Moran’s
January 15, 2014 Order instructed petitioner to file her expert report by March 21, 2014.
It was not until January 24, 2014 that petitioner’s counsel moved for reconsideration,
arguing that petitioner had a right to have her expert give direct testimony at trial. In a
January 29, 2014 Order denying the Motion for Reconsideration, Special Master Moran
explained that the January 15, 2014 Order was intended to expedite the proceedings,
and that the “practice of submitting direct testimony in writing as part of a non-jury case
has been used in a variety of contexts,” as it gives the parties “flexibility in presenting the
expert’s opinions and basis for those opinions” through a “more developed and more
thoroughly presented report.”

      As noted above, on April 2, 2014, petitioner’s case was reassigned to Special
Master Brian H. Corcoran. Petitioner finally filed her expert report on June 20, 2014,

                                                6
followed by a supplemental expert report on December 31, 2014. Petitioner produced Dr.
Beatrice C. Engstrand as her medical expert. Dr. Engstrand is board-certified in neurology
and has completed three residencies, one in medicine and two in neurology. Regarding
Dr. Engstrand’s credentials, Special Master Corcoran noted in his decision, “[a]s she
acknowledged at hearing, however, Dr. Engstrand lacks specialized expertise in the
condition of epilepsy (whether in her education, or through research or study), other than
from what she has learned from those patients she has seen with it.” K.L. v. Sec’y of
Health & Human Servs., 2017 WL 1713110, at *4. In her expert report submitted to the
Special Master on June 20, 2014, Dr. Engstrand offered her opinion that “[s]eizure is
confirmed as an adverse event following HPV Gardasil vaccine” and that “[K.L.’s]
persistent neurological sequelae, poor concentration, migraines, learning disorder and
seizure disorder were caused by a postvaccinal reaction to her HPV/Gardasil vaccine of
February 9, 2010.” Dr. Engstrand’s report indicated that “[t]he most likely mechanism(s)
of injury and it’s [sic] biological basis in this case, is that the release of the cytokine[15]
interleukin-1 beta in the course of the immune response to a [sic] infectious agent such
as a vaccine, could in turn trigger a cluster of afebrile convulsions or seizures.” Dr.
Engstrand’s report placed significant weight on the temporal proximity of the Gardasil
vaccination and K.L.’s first seizure. Dr. Engstrand offered three scientific articles to
support her opinion, the first of which reported on two patients who had experienced
seizures (one of whom had a prior epilepsy diagnosis) out of approximately 700,000
Gardasil vaccinations,16 the second of which did not mention Gardasil,17 and the last of
which described autoimmune reactions to HPV without reference to epilepsy or
seizures.18

        Respondent produced Dr. Shlomo Shinnar as an expert witness, who is board
certified in neurology with special competence in child neurology, and who has additional
qualifications in clinical neurophysiology and epilepsy. Dr. Shinnar produced his expert
report, along with twenty pieces of supporting medical literature on August 25, 2014. Dr.
Shinnar’s report maintained that there neither was any evidence persuasively linking HPV

15 A cytokine is defined as “a generic term for nonantibody proteins released by one cell
population (e.g., primed T lymphocytes) on contact with specific antigen, which act as
intercellular mediators, as in the generation of an immune response.” Dorland’s Illustrated
Medical Dictionary 466.
16Tara Harris, et al., Adverse Events Following Immunization in Ontario’s Female School-
Based HPV Program, 32 Vaccine 1061 (2014), filed as petitioner’s Exhibit 25.
17David C. Wraith, et al., Vaccination and Autoimmune Disease, 362 The Lancet 1659
(2003), filed as petitioner’s Exhibit 26.
18Paolo Pellegrino, et al., On the Relationship Between Human Papilloma Virus Vaccine
and Autoimmune Diseases, 13 Autoimmunity Revs., 736 (2014), filed as petitioner’s
Exhibit 27.

                                              7
with epilepsy, nor any indication that K.L. had experienced an autoimmune reaction from
Gardasil.

        Consistent with Dr. Poduri, referred to by Dr. Shinnar as a “renowned epilepsy
expert,” but in contrast with K.L.’s other treating physicians, who Dr. Shinnar referred to
as “general neurologists,” after a review of K.L.’s medical history, Dr. Shinnar concluded
that the most likely explanation for K.L.’s seizures was idiopathic epilepsy. Dr. Shinnar
specifically contrasted K.L.’s condition with autoimmune epilepsy, which he identified as
a rare condition that is characterized by intractable seizures and a markedly abnormal
EEG with epileptiform activity, none of which were symptoms K.L. demonstrated.
Furthermore, Dr. Shinnar explained that K.L.’s normal MRI and lumbar puncture, lack of
fever, and lack of epileptiform features in her EEG after the first seizure all showed no
evidence of autoinflammation. Regarding Dr. Engstrand’s theory identifying the cytokine
interleukin-1 beta as the mechanism for injury, Dr. Shinnar stressed that scientific
evidence strongly supports that interleukin-1 beta is the chief cytokine that mediates
fever, and, thus, it has been associated with febrile seizures,19 but not afebrile seizures
like the one K.L. experienced. Among the articles Dr. Shinnar included in his expert report
was Lisen Arnheim-Dahlstrom et al., Autoimmune, Neurological and Venous
Thromboembolic Adverse Events After Immunization of Adolescent Girls with
Quadrivalent Human Papillomavirus Vaccine in Denmark and Sweden: Cohort Study, 347
BMJ (2013), filed as respondent’s Exhibit S20 (the Arnheim-Dahlstrom study), which was
a population-based study that compared seizure rates of girls who did and did not receive
the Gardasil vaccine. This study found that the seizure rate was higher for girls who did
not receive the vaccine, which Dr. Shinnar explained meant that it is unlikely the vaccine
causes seizures, and that the data was reliable because it analyzed actual observed
cases, not self-reported events. Dr. Shinnar also pointed out that K.L.’s January 2013
seizure was explainable by her doctor’s failed attempt to reduce her dosage of the Keppra
medication, as opposed to showing that the medication was ineffective against her
condition.

       On December 30, 2014, petitioner filed Dr. Engstrand’s first supplemental expert
report, in which Dr. Engstrand asserted that K.L. had evidenced no seizure symptoms
before petitioner’s February 11, 2010 seizure and offered answers to questions, as
ordered by Special Master Corcoran in an October 9, 2014 Order. Dr. Engstrand’s report
also cited to an article from a Spanish medical journal, M.A. Rodriguez-Galan, et al.,
Adverse Reactions to the Human Papillomavirus Vaccine in the Valencian Community
(2007-2011), 81 Anales Pediatria 303 (2014), filed as petitioner’s Exhibit 29 (the
Valencian study), which analyzed self-reported adverse events following vaccination; out
of 194 events analyzed in the article, six were seizures, and four of these were related to
syncope. Dr. Engstrand’s second supplemental report was filed on May 18, 2015. In it,

19A febrile seizure is one associated with high fever; an afebrile seizure occurs without a
fever. Dorland’s Illustrated Medical Dictionary 411.
20 Petitioner filed exhibits using numerical designations, and respondent filed exhibits
using alphabetical designations.

                                            8
she sought to rebut Dr. Shinnar’s expert report by asserting that autoimmune-related
epilepsy was more common than Dr. Shinnar had suggested, and that a patient could
have it even without an abnormal EEG or prior or concurrent fever. Dr. Engstrand then
asserted that K.L.’s observed symptoms could be associated with autoimmune epilepsy,
and denied the importance of the absence of autoimmune inflammation indicated in K.L.’s
tests. Dr. Engstrand attached literature that described risks associated with Gardasil
generally,21 and articles about epilepsy that did not mention Gardasil.21

       On July 22, 2016 and August 19, 2016, respectively, the parties filed their
prehearing submissions. Petitioner argued that she would be able to meet her burden of
proof under the test laid out by the United States Court of Appeals for the Federal Circuit
in Althen v. Secretary of Health and Human Services, 418 F.3d 1274 (Fed. Cir. 2005), to
prove a causal connection between the vaccine and her alleged injuries by a
preponderance of the evidence. Petitioner emphasized that she was not required to prove
a scientifically certain theory of causation, but only “a plausible medical theory causally
connecting the vaccination and the injury” by a preponderance of the evidence.

        Respondent argued petitioner had failed to meet her burden of proof under the
Althen standard to establish that Gardasil had more likely than not caused K.L.’s alleged
injuries because (1) her causation theory was not supported by reliable scientific
evidence, (2) there was not a sufficient logical relationship between the vaccine and
alleged injury, and (3) petitioner did not establish that her condition began within a
medically appropriate timeframe. Respondent also emphasized that the Special Master
has authority to weigh the credibility of expert testimony and supporting evidence offered,
including their scientific validity.

      An entitlement hearing was held before Special Master Corcoran on September
27, 2016. Although both Special Masters had indicated earlier that the expert reports
would operate as the experts’ direct testimony, and that the experts would only appear at
the hearing for cross examination, at the hearing, Special Master Corcoran did allow both

21  Charlotte Haug, The Risks and Benefits of HPV Vaccination, 302 JAMA 795 (2009),
filed as petitioner’s Exhibit 34; Lucija Topmlijenovic, et al., Too Fast or Not Too Fast: the
FDA’s Approval of Merck’s HPV Vaccine Gardasil, J.L. Med. & Ethics 673 (2012), filed as
petitioner’s Exhibit 36; and Gardasil Prescribing Information, Merck & Co., Inc. (2015),
filed as petitioner’s Exhibit 37.
21 Ignacio Valencia, Epilepsy in Systemic Autoimmune Disorders, 21 Seminars in
Pediatric Neurology 226 (2014), filed as petitioner’s Exhibit 32; Jehan Suleiman, et al.
Autoimmune Epilepsy in Children: Case Series and Proposed Guidelines for
Identification, 54 Epilepsia 1036 (2013), filed as petitioner’s Exhibit 33; and Barbara A.
Slade, et al. Post Licensure Safety Surveillance for Quadrivalent Human Papillomavirus
Recombinant Vaccine, 302 JAMA 750 (2009), filed as petitioner’s Exhibit 35.

                                             9
parties’ experts to give brief direct testimony. At the opening of the hearing, Special
Master Corcoran stated,

       What I am going to allow each side to do is to very briefly, in less than five
       minutes, if not quicker, allow the expert to provide the essence of what their
       testimony is going to be or what their report says, and then we will go into
       cross examination and then we’ll have redirect, and then, at that time,
       counsel will have the opportunity to follow up with their expert. That’s the
       process that I’m going to follow today.

It is noteworthy that in her direct testimony, petitioner’s expert witness, Dr. Engstrand,
abandoned the theory she had proposed in her first submitted report, which specified the
interleukin-1 beta cytokine as the mechanism of K.L.’s injury, and instead suggested that
K.L.’s brain had been irritated and become hyper-excitable from “an immune-mediated
response, like an interleukin or any other cytokine, not knowing which one in particular,”
triggered by the vaccine. In response to questioning at the hearing by Special Master
Corcoran, Dr. Engstrand said she had modified her theory because she realized that
K.L.’s cytokines had never been tested, so there was no way to be certain that interleukin-
1 beta had been the specific trigger. When Special Master Corcoran asked Dr. Engstrand
to elaborate on her modified theory of causation, Dr. Engstrand admitted that she was
relying heavily on the fact of the seizure, and not on direct evidence of cytokines,
inflammation or indicia in K.L.’s MRI. Dr. Engstrand contended that even though K.L.’s
tests were normal, her lumbar puncture did not include testing for cytokines, and stated,
“But I don’t fault them because that’s not routinely done.” She also testified that the
temporal association between the February 9, 2010 vaccination and K.L.’s seizure two
days later was medically appropriate.

         During cross examination, counsel for the respondent asked Dr. Engstrand
questions about the evidence in the record regarding K.L.’s learning, literacy, and social
difficulties which predated her HPV vaccination, which Dr. Engstrand maintained had
worsened after K.L. received the vaccine. On re-direct examination, petitioner’s counsel
asked questions about petitioner’s Exhibit 17, K.L.’s comprehensive learning evaluation,
and Dr. Engstrand responded that K.L. had experienced a decline in her cognitive abilities
post-seizure. On re-cross, however, Dr. Engstrand admitted that K.L. may have had a
cognitive problem well before her seizure, as indicated in notes about learning difficulties
early in K.L.’s education in the comprehensive learning evaluation.

       In response to questioning regarding the fact that K.L.’s seizure was afebrile, Dr.
Engstrand was unable to point to anything in the literature she had cited in her expert
reports that showed a connection between the HPV vaccination and afebrile seizures. Dr.
Engstrand referenced data reported in the Valencian study to support her theory that
there was a logical relationship between K.L.’s vaccination and seizures. Dr. Engstrand
remarked that the fact that the Valencian study made no mention of whether the seizures
were febrile meant that they must have been afebrile, because “if they were febrile
seizures, [the authors] would have to comment on it and they didn’t comment on it.”
Regarding K.L.’s consultation with Dr. Poduri, Dr. Engstrand noted Dr. Poduri had
included in her records that K.L. “notably had her Gardasil vaccination two days prior to

                                            10
the first seizure,” but on re-cross examination admitted that even with this knowledge, Dr.
Poduri had diagnosed K.L.’s epilepsy as idiopathic.

        In his testimony, Dr. Shinnar stated that interleukin-1 beta was irrelevant in this
case because patients cannot have interleukin-1 beta-mediated reactions without fever,
and K.L. did not have a fever with her seizure. Dr. Shinnar indicated that K.L. had
idiopathic epilepsy, likely caused by her genetic predisposition and not by Gardasil, based
on his review of her medical records, including her normal test results, family history of
epilepsy, response to treatment, and other co-morbidities. Dr. Shinnar also noted that
K.L.’s learning deficits predated and were not exacerbated by her vaccine, based on
notes about K.L.’s cognitive abilities over time in the comprehensive learning evaluation
and supported in his report by relevant medical literature. Dr. Shinnar noted that the
literature Dr. Engstrand relied on that cited seizures associated with syncope was
irrelevant to K.L.’s case because such seizures are “very different than an epileptic
seizure.” Dr. Shinnar also noted that, while K.L.’s normal EEG was not inconsistent with
an epileptic seizure, it was inconsistent with autoimmune epilepsy and made Dr.
Engstrand’s theory “extremely unlikely.” He also pointed out that cytokine testing is not
even available in a lumbar puncture, as Dr. Engstrand had suggested.

       On cross examination, Dr. Shinnar stated that “[t]emporal relationship is one of the
factors used” in a causation analysis, “but does not stand by itself,” especially when
analyzing a common type of seizure experienced by adolescents. Dr. Shinnar also
explained that “there is no evidence in this case that the prolonged seizure is a cause of
her epilepsy; it is the onset of her epilepsy.” When questioned about the large “population-
based study” he cited in his expert report (the Arnheim-Dahlstrom study), Dr. Shinnar
noted that the study’s finding that the seizure rate was higher in patients who never
received the Gardasil vaccine indicated that it was unlikely the vaccine caused an
increased risk of seizures. By comparison, Dr. Shinnar testified that the Valencian study
was not reliable evidence for petitioner’s theory because its journal of publication was “an
obscure journal” and the study relied on self-reported adverse events, compared to
studies like Arnheim-Dahlstrom, which analyzed actual diagnosed and observed
vaccination cases, and was published in a “highly regarded peer-reviewed journal.” Dr.
Shinnar also pointed to the publication by the Institute of Medicine22 he had cited in his
expert report, which, pursuant to a contract, was charged by the Health Resources and
Services Administration (HRSA)23 with reviewing the available data on adverse events or
complications resulting from vaccines, including neurological events like seizures.24 See

22 The Institute of Medicine is now affiliated with the Health and Medicine Division of the
National     Academies      of    Sciences,       Engineering    and     Medicine.     See
http://www.nationalacademies.org/hmd/.
23The HRSA is an agency of the United States Department of Health and Human
Services that administers the Vaccine Injury Compensation Program (VICP) under the
Vaccine Act. See www.hrsa.gov.
24   The Report Brief explains,

                                            11
Institute of Medicine, National Academies of Science, Adverse Effects of Vaccines:
Evidence and Causality (2012). This report did not list epilepsy among the possible
complications of Gardasil, and noted that there was insufficient data connecting it with
other neurologic complications. See id.

       The parties filed post-hearing briefs on November 14, 2016. Respondent’s post-
hearing brief reiterated its arguments from its Vaccine Rule 4(c) report that petitioner’s
claim should fail because she did not meet her burden of proof under Althen to
demonstrate by a preponderance of the evidence that the vaccine was more likely than
not the cause of her alleged injuries. Respondent further argued, as Dr. Shinnar had
explained at the hearing, that petitioner’s expert’s theory of K.L.’s condition was
unsupported by scientific evidence or by K.L.’s clinical symptoms, whereas K.L.’s
symptoms were consistent with other known causes of epileptic seizures, as her treating
physician’s diagnosis had indicated. Petitioner’s post-hearing memorandum relied on Dr.
Engstrand’s expert report and testimony regarding the cause of K.L.’s medical condition,
and argued that Dr. Poduri’s diagnosis should not be considered in evaluating K.L.’s right
to compensation because “a diagnosis of an idiopathic disease or injury cannot be used
to deny a petitioner compensation [under the Vaccine Act] because it is of an unknown
cause.”

        The Special Master subsequently granted petitioner’s request to file an additional
post-hearing affidavit from Dr. Engstrand with additional exhibits. On September 6, 2016,
petitioner’s expert filed the affidavit, attaching three more scientific studies and the
introduction to a book discussing adverse effects of many types of vaccines, Committee
to Review Adverse Effects of Vaccines: Institute of Medicine 27, Adverse Effects of
Vaccines: Evidence and Causality, (Kathleen Stratton et al., eds., 2011), filed as
petitioner’s Exhibit 44. Dr. Engstrand stated in her affidavit that one of the scientific studies
supported the possibility of afebrile seizures following an HPV vaccine, Nigel W. Crawford
et al., Syncope and Seizures Following Human Papillomavirus Vaccination: A
Retrospective Case Series, 194 Med. J. Austl. 16 (2011), filed as petitioner’s Exhibit 41
(the Crawford study), which was a retrospective study of passive surveillance reporting

       Under the National Childhood Vaccine Injury Act of 1986, Congress
       established the National Vaccine Injury Compensation Program (VICP) to
       provide compensation to people injured by vaccines . . . . The Health
       Resources and Services Administration (HRSA), the agency within the
       Department of Health and Human Services that administers VICP, can use
       evidence that demonstrates a causal link between an adverse event and a
       vaccine to streamline the claims process. As such, HRSA asked the
       Institute of Medicine (IOM) to review a list of adverse events associated with
       vaccines covered by VICP and to evaluate the scientific evidence about the
       event-vaccine relationship.

Adverse Events of Vaccines: Evidence and Causality, Report Brief, Chapter 9, Human
Papillomavirus Vaccine, 505-524, Institutes of Medicine, National Academies Press,
2012.

                                               12
adverse vaccine events. The affidavit also referenced a report that studied the
involvement of cytokines in epilepsy, Gang Li et al., Cytokines and Epilepsy, 20 Seizure
249 (2011), filed as petitioner’s Exhibit 42 (the Li study). The third study, Sarah von
Spiczak et al., A Retrospective Population-Based Study on Seizures Related to Childhood
Vaccination, 52 Epilepsia 1506 (2011), filed as petitioner’s Exhibit 43 (the Spiczak study),
referenced afebrile seizures experienced by children under six years old, none of whom
had been vaccinated with Gardasil.

        After reviewing the administrative record, on March 17, 2017, Special Master
Corcoran denied petitioner’s claim seeking compensation for her alleged injuries, which
petitioner argued were the result of her Gardasil vaccination, finding that petitioner had
failed to carry her burden of proof to show by a preponderance of the evidence that the
vaccine had caused her injuries under the three-pronged Althen test. See K.L. v. Sec’y of
Health & Human Servs., 2017 WL 1713110, at *14. Specifically, Special Master Corcoran
found:

       Beyond the close temporal relationship between K.L.’s receipt of the third
       dose of Gardasil and onset of her first diagnosed seizure, the medical
       record does not support the conclusion that her epilepsy was vaccine-
       caused. More fundamentally, she has not established a reliable scientific
       theory that the HPV vaccine could cause epilepsy of the kind experienced
       by Petitioner.

Id. Special Master Corcoran was not persuaded by petitioner’s expert witness or the
literature submitted by petitioner, finding also that petitioner’s theory of causation
“exceed[ed] the expertise of Dr. Engstrand to espouse,” because the crux of her theory
required expertise in immunology and Dr. Engstrand had not demonstrated any
competence or skill as an immunologist. See id.

        With regard to the first prong of the Althen test, whereby petitioner must show a
reliable medical theory causally connecting the vaccination and injury, the Special Master
found overall that petitioner’s causation theory was not supported by reliable and
reasonable scientific evidence. See id. The Special Master determined that “[w]hile the
individual articles offered proved reasonable and reliable individually, taken as a whole
they do not assist Petitioner’s case,” because “much of the literature offered either
involved autoimmune forms of epilepsy (which are irrelevant under the facts of the case),
different vaccines, or involved the relationship between the HPV vaccine and febrile
seizures, which K.L. unquestionably never experienced.” Id. The Special Master further
wrote:

       The epidemiologic evidence, such as the Valencian Article, Crawford
       [study], and Spiczak [study], offered to suggest that afebrile seizures are
       also possible not only involved VAERS [Vaccine Adverse Event Reporting
       System]-like passive surveillance (which is inherently less trustworthy than
       a retrospective study observing actual diagnosed instances of illness or
       conditions like epilepsy following vaccination) but was commonly
       distinguishable when examined closely.

                                            13
See id. Special Master Corcoran noted that while petitioner need not prove scientific
causation to a certainty, the court is permitted to scrutinize the evidence a claimant offers
in support of her theory, including its scientific validity. The Special Master found that the
authority cited by petitioner’s expert in support of her theory “was insufficiently related to
vaccines, or did not even facially support the concept.” See id.

       The Special Master highlighted how Dr. Shinnar had refuted Dr. Engstrand’s
original theory of causation in her first expert report of interleukin-1 beta as the primary
cytokine involved in causing K.L.’s symptoms when “[i]n response, Dr. Shinnar noted that
this cytokine was associated with fever – but K.L. unquestionably had experienced an
afebrile seizure, making it impossible for that particular cytokine to have been involved in
the alleged process by which the HPV vaccine caused K.L.’s seizure.” Id. at *15. The
Special Master noted that Dr. Engstrand subsequently had modified her theory of
causation at the hearing and in a post-hearing affidavit. See id. The Special Master also
analyzed the literature Dr. Engstrand attached to her reports and affidavit and found the
studies “largely unpersuasive.” See id. For example, the Valencian study “[made] no
mention of whether the few reported instances of seizure were afebrile.” Id. At the hearing,
during cross examination by petitioner’s counsel, Dr. Engstrand made the following
assertion:

              Q: So, you’re assuming that they did not have fevers; it doesn’t say
       they did not have fevers. You’re not quoting the article.

             A: If they were febrile seizures, they would have to comment on it
       and they didn’t comment on it. They would have said seizures with fever
       and there’s no mention of a fever with the seizures.

The Special Master noted in his decision that this assumption was “a somewhat
unreasonable inference.” Id.

        Regarding the Li study, the Special Master found that the study showed an
association between the effect seizures have on cytokine upregulation and not “the other
way around,” i.e., upregulation of cytokines causing seizures per Dr. Engstrand’s theory.
See id. The Special Master went on to closely analyze and explain how other studies
provided by petitioner following the hearing were similarly unhelpful to her case. See id.
The Special Master found that the evidence respondent cited in support of its theory of
the causes of K.L.’s medical condition by respondent was supported by more reliable and
more persuasive evidence, including studies that tended to show that Gardasil was not a
likely cause of injuries of the kind K.L. experienced, because those studies had analyzed
observed cases rather than self-reported reactions. See id.

        Because the Special Master found that petitioner had failed to carry her burden of
proof under the first Althen prong, he noted that it was “unnecessary to discuss
Petitioner’s showings under the other two Althen prongs,” but, nevertheless, considered
and addressed each. See id. at *16. Regarding the second Althen prong, whereby
petitioner must show by a preponderance of the evidence that there is a logical sequence
of cause and effect between the vaccine and her alleged injury, the Special Master found

                                             14
that petitioner “had not successfully demonstrated with preponderant evidence that the
HPV vaccine did cause her initial seizure as alleged.” See id. The Special Master
considered the testimony of respondent’s expert more convincing, and found:

       K.L.’s medical records indicated no signs of an autoimmune process
       occurring contemporaneous with her initial hospitalization, or the kind of
       biologic markers that would reflect the cytokine upregulation that Dr.
       Engstrand opined was happening herein. Rather, her test results
       throughout treatment were normal, including an MRI and multiple EEGs.
       Dr. Shinnar also effectively distinguished K.L.’s presentation with that of a
       patient with autoimmune epilepsy . . . . In addition, particularly trustworthy
       treaters with significant epilepsy expertise, like Dr. Poduri, were aware of
       the vaccine’s administration but concluded, based on their review of the
       developing medical record, that more likely than not K.L.’s epilepsy was
       idiopathic.

Id.

       As to the third Althen prong, whereby petitioner must show that there is a proximate
temporal relationship between vaccination and the injury, the Special Master noted that
temporal proximity would not alone support a claim for compensation under the Vaccine
Act. See id. Moreover, the Special Master determined petitioner’s expert had “offered little
authority to support Petitioner’s conclusion that [the timeframe between her vaccination
and the alleged injury was] medically appropriate.” See id. The Special Master
“acknowledge[d] that a two-day period between vaccination and seizure has been
deemed medically acceptable in other [Vaccine Injury] Program cases involving epilepsy.”
See id. Regarding the third Althen prong, the Special Master emphasized that “even were
[he] to find that the balance of evidence on this matter barely favored K.L., that
determination would not alter” his decision denying entitlement, because he had already
found that petitioner’s causation theory was “too deficient” and “unsupported by the actual
medical history,” and, thus, failed to meet the first Althen prong. See id. at *17. Moreover,
the Special Master noted that defining a “medically appropriate” timeframe necessarily
refers to a theory of causation. See id. Therefore, given that petitioner’s claim alleged a
non-Table injury, and finding that the weight of evidence did not support her claim, Special
Master Corcoran denied compensation. See id.

       On April 16, 2017, petitioner filed a Motion for Review of the Special Master’s
decision, and the case was assigned to the undersigned. In her motion, petitioner alleges
that the Special Master violated due process, that he impermissibly increased petitioner’s
burden of proof, and that the Special Master’s ruling was arbitrary and capricious.

       On May 17, 2017, the Secretary of Health and Human Services’ filed a
Memorandum in Response to Petitioner’s Motion for Review asserts that the Vaccine
Rules expressly confer discretionary authority on the Special Master to decide the best
manner in which to proceed, including to allow direct testimony by the experts or to take
into evidence the experts’ written reports as the direct testimony. Regarding petitioner’s
argument that the Special Master increased petitioner’s burden of proof, respondent

                                             15
argues that the Special Master correctly applied the Althen test to petitioner’s case.
Respondent also argues that, as the factfinder, the Special Master’s weighing and
evaluation of evidence is entitled to substantial deference by this court. According to
respondent, because Special Master Corcoran carefully considered the relevant
evidence, his decision was not arbitrary or capricious and this court should affirm his
decision.

                                        DISCUSSION

         Although petitioner’s Motion for Review is confusingly structured and the filings are
repetitive and poorly articulated, petitioner appears to assert three main grounds to argue
why the Special Master’s decision should be reversed. First, petitioner alleges that the
procedures followed by the Special Master during the September 27, 2016 entitlement
hearing violated due process. Specifically, petitioner alleges that the Order by the Special
Master previously assigned to this case, that the parties’ expert reports would constitute
their direct testimony, violated petitioner’s “fundamental right to a full and fair hearing,” as
guaranteed by Vaccine Rules 3(b)(2) and 8. Second, petitioner alleges that the Special
Master erred by applying the incorrect legal standard to analyze whether petitioner met
her burden of proof for compensation under the Vaccine Act. Third, petitioner alleges that
the Special Master’s decision was arbitrary and capricious because it did not address
alleged flaws in the testimony of respondent’s expert, while, simultaneously, unfairly
criticizing petitioner’s expert, it improperly discounted the medical literature presented by
petitioner, and it misinterpreted or failed to review “numerous exhibits” included in the
record. The government, however, argues that the Special Master did not violate due
process because the Special Master has the discretion to have the experts’ written reports
serve as direct testimony, that the Special Master properly considered the credibility of
the expert witnesses and evidence presented, and that the Special Master’s decision was
not arbitrary or capricious because it was based on a thorough review of the evidence in
the record, including the expert testimony presented.

       When reviewing a Special Master's decision, the assigned Judge of the United
States Court of Federal Claims shall:

       (A) uphold the findings of fact and conclusions of law of the special master
       and sustain the special master's decision,

       (B) set aside any findings of fact or conclusions of law of the special master
       found to be arbitrary, capricious, an abuse of discretion, or otherwise not in
       accordance with law and issue its own findings of fact and conclusions of
       law, or

       (C) remand the petition to the special master for further action in accordance
       with the court's direction.

42 U.S.C. § 300aa-12(e)(2). The legislative history of the Vaccine Act states: “The
conferees have provided for a limited standard for appeal from the [special] master's
decision and do not intend that this procedure be used frequently, but rather in those

                                              16
cases in which a truly arbitrary decision has been made." H.R. Rep. No. 101-386, at 517
(1989) (Conf. Rep.), reprinted in 1989 U.S.C.C.A.N. 3018, 3120.

       In order to recover under the Vaccine Act, petitioners must prove that the vaccine
caused the purported injury. See W.C. v. Sec’y of Health & Human Servs., 704 F.3d
1352, 1355-56 (Fed. Cir. 2013) (“The Vaccine Act created the National Vaccine Injury
Compensation Program, which allows certain petitioners to be compensated upon
showing, among other things, that a person ‘sustained, or had significantly aggravated’ a
vaccine-related ‘illness, disability, injury, or condition.’” (quoting 42 U.S.C. § 300aa–
11(c)(1)(C))); Lombardi v. Sec’y of Health & Human Servs., 656 F.3d 1343, 1350 (Fed.
Cir. 2011) (“A petitioner seeking compensation under the Vaccine Act must prove by a
preponderance of the evidence that the injury or death at issue was caused by a
vaccine.”); see also Shapiro v. Sec’y of Health & Human Servs., 105 Fed. Cl. 353, 358
(2012), aff’d, 503 F. App’x 952 (Fed. Cir. 2013); Jarvis v. Sec’y of Health & Human Servs.,
99 Fed. Cl. 47, 54 (2011).

       Regarding the standard of review, articulated in Markovich v. Secretary of Health
and Human Services, the United States Court of Appeals for the Federal Circuit wrote,
“[u]nder the Vaccine Act, the Court of Federal Claims reviews the Chief Special Master's
decision to determine if it is ‘arbitrary, capricious, an abuse of discretion, or otherwise not
in accordance with the law.’ 42 U.S.C. § 300aa-12(e)(2)(B).” Markovich v. Sec’y of Health
& Human Servs., 477 F.3d 1353, 1355-56 (Fed. Cir.), cert. denied, 552 U.S. 816 (2007);
see also Deribeaux ex rel. Deribeaux v. Sec’y of Health & Human Servs., 717 F.3d 1363,
1366 (Fed. Cir.) (The United States Court of Appeals for the Federal Circuit stated that
“we ‘perform[ ] the same task as the Court of Federal Claims and determine[ ] anew
whether the special master's findings were arbitrary or capricious.’” (quoting Lampe v.
Sec’y of Health & Human Servs., 219 F.3d 1357, 1360 (Fed. Cir. 2000))) (brackets in
original), reh’g and reh’g en banc denied (Fed. Cir. 2013); W.C. v. Sec’y of Health &
Human Servs., 704 F.3d at 1355; Hibbard v. Sec’y of Health & Human Servs., 698 F.3d
1355, 1363 (Fed. Cir. 2012); Avera v. Sec’y of Health & Human Servs., 515 F.3d 1343,
1347 (Fed. Cir.) (“Under the Vaccine Act, we review a decision of the special master
under the same standard as the Court of Federal Claims and determine if it is ‘arbitrary,
capricious, an abuse of discretion, or otherwise not in accordance with law.’” (quoting 42
U.S.C. § 300aa-12(e)(2)(B))), reh’g and reh’g en banc denied (Fed. Cir. 2008); de Bazan
v. Sec’y of Health & Human Servs., 539 F.3d 1347, 1350 (Fed. Cir.), reh’g and reh’g en
banc denied (Fed. Cir. 2008); Althen v. Sec’y of Health & Human Servs., 418 F.3d at
1277; Dodd v. Sec’y of Health & Human Servs., 114 Fed. Cl. 43, 47 (2013); Taylor v.
Sec’y of Health & Human Servs., 108 Fed. Cl. 807, 817 (2013). The arbitrary and
capricious standard is “well understood to be the most deferential possible.” Munn v.
Sec’y of Health & Human Servs., 970 F.2d 863, 870 (Fed. Cir. 1992).

       Therefore, this court may set aside a Special Master’s decision only if the court
determines that the “findings of fact or conclusion of law of the special master . . . [are]
arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law . . . .”
42 U.S.C. § 300aa-12(e)(2)(B); see also Lombardi v. Sec’y of Health & Human Servs.,
656 F.3d at 1350 (“We uphold the special master's findings of fact unless they are arbitrary
or capricious.”) (internal citations omitted); Moberly ex rel. Moberly v. Sec’y of Health &

                                              17
Human Servs., 592 F.3d 1315, 1321 (Fed. Cir. 2010); Markovich v. Sec’y of Health &
Human Servs., 477 F.3d at 1356-57; Lampe v. Sec’y of Health & Human Servs., 219 F.3d
at 1360. The United States Court of Appeals for the Federal Circuit has indicated that:

       These standards vary in application as well as degree of deference. Each
       standard applies to a different aspect of the judgment. Fact findings are
       reviewed by us, as by the Claims Court judge, under the arbitrary and
       capricious standard; legal questions under the “not in accordance with law”
       standard . . . ; and discretionary rulings under the abuse of discretion
       standard. The latter will rarely come into play except where the special
       master excludes evidence.

Munn v. Sec’y of Dep’t of Health & Human Servs., 970 F.2d at 871 n.10; see also Carson
ex rel. Carson v. Sec’y of Health & Human Servs., 727 F.3d 1365, 1369 (Fed. Cir. 2013);
Deribeaux ex rel. Deribeaux v. Sec’y of Health & Human Servs., 717 F.3d at 1366; W.C.
v. Sec’y of Health & Human Servs., 704 F.3d at 1355; Griglock v. Sec’y of Health &
Human Servs., 687 F.3d 1371, 1374 (Fed. Cir. 2012); Porter v. Sec'y of Health & Human
Servs., 663 F.3d 1242, 1249 (Fed. Cir. 2011) (citing Broekelschen v. Sec'y of Health &
Human Servs., 618 F.3d 1339, 1345 (Fed. Cir. 2010)) (explaining that the reviewing court
“do[es] not reweigh the factual evidence, assess whether the special master correctly
evaluated the evidence, or examine the probative value of the evidence or the credibility
of the witnesses—these are all matters within the purview of the fact finder”); Dodd v.
Sec’y of Health & Human Servs., 114 Fed. Cl. at 56. “With regard to both fact-findings
and fact-based conclusions, the key decision maker in the first instance is the special
master. The Claims Court owes these findings and conclusions by the special master
great deference – no change may be made absent first a determination that the special
master was ‘arbitrary and capricious.’” Munn v. Sec’y of Health & Human Servs., 970
F.2d at 870; see also 42 U.S.C. § 300aa-12(e)(2)(B).

       Generally, “if the special master ‘has considered the relevant evidence of record,
drawn plausible inferences and articulated a rational basis for the decision, reversible
error will be extremely difficult to demonstrate.’” Hibbard v. Sec'y of Health & Human
Servs., 698 F.3d at 1363 (quoting Hines on Behalf of Sevier v. Sec’y of Dep’t of Health &
Human Servs., 940 F.2d 1518, 1528 (Fed. Cir. 1991)); see also Porter v. Sec'y of Health
& Human Servs., 663 F.3d at 1253-54; Lampe v. Sec’y of Health & Human Servs., 219
F.3d at 1360; Avila ex rel. Avila v. Sec’y of Health & Human Servs., 90 Fed. Cl. 590, 594
(2009); Dixon v. Sec’y of Health & Human Servs., 61 Fed. Cl. 1, 8 (2004) (“The court’s
inquiry in this regard must therefore focus on whether the special master examined the
‘relevant data’ and articulated a ‘satisfactory explanation for its action including a “rational
connection between the facts found and the choice made.” (quoting Motor Vehicle Mfrs.
Ass’n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983) (quoting Burlington Truck
Lines, Inc. v. United States, 371 U.S. 156, 168 (1962)))).

       As noted by the United States Court of Appeals for the Federal Circuit:

       Congress assigned to a group of specialists, the special masters within the
       Court of Federal Claims, the unenviable job of sorting through these painful

                                              18
       cases and, based upon their accumulated expertise in the field, judging the
       merits of the individual claims. The statute makes clear that, on review, the
       Court of Federal Claims is not to second guess the special masters [sic]
       fact-intensive conclusions; the standard of review is uniquely deferential for
       what is essentially a judicial process. Our cases make clear that, on our
       review . . . we remain equally deferential. That level of deference is
       especially apt in a case in which the medical evidence of causation is in
       dispute.

Deribeaux ex rel. Deribeaux v. Sec'y of Health & Human Servs., 717 F.3d at 1366 (quoting
Hodges v. Sec'y of Health & Human Servs., 9 F.3d 958, 961 (Fed. Cir. 1993))
(modification in original); Hibbard v. Sec'y of Health & Human Servs., 698 F.3d at 1363;
Locane v. Sec'y of Health & Human Servs., 685 F.3d 1375, 1380 (Fed. Cir. 2012). The
Court of Appeals for the Federal Circuit has further explained that the reviewing courts
“‘do not sit to reweigh the evidence. [If] the special master's conclusion [is] based on
evidence in the record that [is] not wholly implausible, we are compelled to uphold that
finding as not being arbitrary and capricious.’” See Deribeaux ex rel. Deribeaux v. Sec'y
of Health & Human Servs., 717 F.3d at 1367 (quoting Lampe v. Sec'y of Health & Human
Servs., 219 F.3d at 1363) (modification in original); see also Hibbard v. Sec'y of Health &
Human Servs., 698 F.3d at 1363 (citing Cedillo v. Sec’y of Health & Human Servs., 617
F.3d 1328, 1338 (Fed. Cir. 2010)).

        The Special Master has discretion to determine the relative weight of evidence
presented, including contemporaneous medical records and oral testimony. See Burns v.
Sec’y of Health & Human Servs., 3 F.3d 415, 417 (Fed. Cir. 1993) (finding that the Special
Master had thoroughly considered evidence in record, had discretion not to hold an
additional evidentiary hearing); Hibbard v. Sec’y of Health & Human Servs., 698 F.3d at
1368 (finding it was not arbitrary or capricious for the Special Master to weigh diagnoses
of different treating physicians against one another, including when their opinions
conflict). “‘Clearly it is not then the role of this court to reweigh the factual evidence, or to
assess whether the special master correctly evaluated the evidence. And of course we
do not examine the probative value of the evidence or the credibility of the witnesses.
These are all matters within the purview of the fact finder.’” Dodd v. Sec’y of Health &
Human Servs., 114 Fed. Cl. at 56 (quoting Munn v. Sec'y of Dept. of Health & Human
Servs., 970 F.2d at 870 n.10); see also Rich v. Sec’y of Health & Human Servs., 129 Fed.
Cl. 642, 655 (2016); Paluck v. Sec'y of Health & Human Servs., 104 Fed. Cl. 457, 467
(2012) (“A special master's findings regarding the probative value of the evidence and the
credibility of witnesses will not be disturbed so long as they are ‘supported by substantial
evidence.’” (quoting Doe v. Sec'y of Health & Human Servs., 601 F.3d 1349, 1355 (Fed.
Cir.), cert. denied, 562 U.S. 1029 (2010))).

        Additionally, as instructed by the United States Court of Appeals for the Federal
Circuit, “[u]nder the Vaccine Act, Special Masters are accorded great deference in
determining the credibility and reliability of expert witnesses. Indeed, we have held that a
Special Master's ‘credibility determinations are virtually unreviewable.’” Cedillo v. Sec’y
of Health & Human Servs., 617 F.3d at 1347 (quoting Hanlon v. Sec’y of Health & Human
Servs., 191 F.3d 1344, 1349 (Fed. Cir. 2010) (quotation omitted)); see also Porter v. Sec’y

                                               19
of Health & Human Servs., 663 F.3d at 1253-54 (“’Reversible error will be extremely
difficult to demonstrate’ where the Special Master ‘has considered the relevant evidence
of record, drawn plausible inferences and articulated a rational basis for the decision.’”)
(quoting Hines on behalf of Sevier v. Sec’y of Health & Human Servs., 940 F.2d at 1528);
Lombardi v. Sec’y of Health & Human Servs., 656 F.3d at 1353; Anderson v. Sec’y of
Health & Human Servs., 131 Fed. Cl. 735, 752 (2017); Holt v. Sec’y of Health & Human
Servs., 132 Fed. Cl. 194, 199 (2017). Additionally, a Special Master is “not required to
discuss every piece of evidence or testimony in [his or] her decision.” Snyder ex rel.
Snyder v. Sec’y of Health & Human Servs., 88 Fed. Cl. 706, 728 (2009); see also Paluck
ex rel. Paluck v. Sec’y of Health & Human Servs., 104 Fed. Cl. at 467 (“[W]hile the special
master need not address every snippet of evidence adduced in the case, see id. [Doe v.
Sec’y of Health & Human Servs., 601 F.3d at 1355], he cannot dismiss so much contrary
evidence that it appears that he ‘simply failed to consider genuinely the evidentiary record
before him.’” (quoting Campbell v. Sec’y of Health & Human Servs., 97 Fed. Cl. 650, 668
(2011))).

     Regarding the causation analysis, as indicated by the United States Court of
Appeals for the Federal Circuit in Althen v. Secretary of Health and Human Services:

       The [Vaccine] Act provides for the establishment of causation in one of two
       ways: through a statutorily-prescribed presumption of causation upon a
       showing that the injury falls under the Vaccine Injury Table (“Table injury”),
       see 42 U.S.C. § 300aa-14(a); or where the complained-of injury is not listed
       in the Vaccine Injury Table (“off-Table injury”), by proving causation in fact,
       see 42 U.S.C. §§ 300aa-13(a)(1), -11(c)(1)(C)(ii)(I).

Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1278; W.C. v. Sec'y of Health &
Human Servs., 704 F.3d at 1356; Broekelschen v. Sec'y of Health & Human Servs., 618
F.3d at 1346; Pafford v. Sec’y of Health & Human Servs., 451 F.3d 1352, 1356 (Fed.
Cir.), reh’g and reh’g en banc denied (Fed. Cir. 2006), cert. denied, 551 U.S. 1102 (2007);
Dodd v. Sec’y of Health & Human Servs., 114 Fed. Cl. at 50; Paluck v. Sec'y of Health &
Human Servs., 104 Fed. Cl. 467-68; Fesanco v. Sec’y of Health & Human Servs., 99 Fed.
Cl. 28, 31 (2011). The United States Supreme Court has explained that:

       Claimants who show that a listed injury first manifested itself at the
       appropriate time are prima facie entitled to compensation. No showing of
       causation is necessary; the Secretary bears the burden of disproving
       causation. A claimant may also recover for unlisted side effects, and for
       listed side effects that occur at times other than those specified in the Table,
       but for those the claimant must prove causation.

Bruesewitz v. Wyeth LLC, 131 S. Ct. 1068, 1073-74 (2011) (footnotes omitted); Kennedy
v. Sec’y of Health & Human Servs., 99 Fed. Cl. 535, 539 (2011), aff’d, 485 F. App’x. 435
(Fed. Cir. 2012).

      As both parties recognize, the injuries petitioner alleges she suffered as a result of
the Gardasil vaccination are not included on the Vaccine Injury Table. See 42 U.S.C.

                                             20
§ 300aa-14. Petitioner, therefore, must proceed under an off-Table theory of recovery.
Under the off-Table theory of recovery, a petitioner is entitled to compensation if he or
she can demonstrate, by a preponderance of the evidence, see 42 U.S.C. § 300aa-
13(a)(1)(A), that the recipient of the vaccine sustained, or had significantly aggravated,
an illness, disability, injury, or condition not set forth in the Vaccine Injury Table, but which
was caused by a vaccine that is listed on the Vaccine Injury Table. See 42 U.S.C. §
300aa-11(c)(1)(C)(ii)(I); see also LaLonde v. Sec’y of Health & Human Servs., 746 F.3d
1334, 1339 (Fed. Cir. 2014); W.C. v. Sec’y of Health & Human Servs., 704 F.3d at 1356
(“Nonetheless, the petitioner must do more than demonstrate a ‘plausible’ or ‘possible’
causal link between the vaccination and the injury; he must prove his case by a
preponderance of the evidence.” (quoting Moberly ex rel. Moberly v. Sec’y of Health &
Human Servs., 592 F.3d at 1322)); Althen v. Sec’y of Health & Human Servs., 418 F.3d
at 1278; Hines on Behalf of Sevier v. Sec’y of Dep’t of Health & Human Servs., 940 F.2d
at 1525. While scientific certainty is not required, the Special Master “is entitled to require
some indicia of reliability to support the assertion of the expert witness.” Moberly ex rel.
Moberly ex rel. v. Sec’y of Health & Human Servs., 592 F.3d at 1324; see also Hazlehurst
v. Sec’y of Health & Human Servs., 88 Fed. Cl. 473, 439 (2009), aff’d, 604 F.3d 1343
(Fed. Cir. 2010) (quoting Andreu ex rel. Andreu v. Sec’y of Health & Human Servs., 569
F.3d 1367, 1379 (Fed. Cir. 2009)).

        Additionally, petitioner must prove causation-in-fact. See Grant v. Sec'y of Health
& Human Servs., 956 F.2d 1144, 1147-48 (Fed. Cir. 1992). The United States Court of
Appeals for the Federal Circuit has held that causation-in-fact in the Vaccine Act context
is the same as the “legal cause” in the general torts context. See Shyface v. Sec’y of
Health & Human Servs., 165 F.3d 1344, 1352 (Fed. Cir. 1999). Therefore, drawing from
the Restatement (Second) of Torts, the vaccine is a cause-in-fact when it is “a substantial
factor in bringing about the harm.” de Bazan v. Sec’y of Health & Human Servs., 539 F.3d
at 1351 (quoting the Restatement (Second) of Torts § 431(a)); see also Deribeaux ex rel.
Deribeaux v. Sec’y of Health & Human Servs., 717 F.3d at 1367 (“To prove causation, a
petitioner must show that the vaccine was ‘not only a but-for cause of the injury but also
a substantial factor in bringing about the injury.’” (quoting Shyface v. Sec’y of Health &
Human Servs., 165 F.3d at 1352–53)). A “‘substantial factor’ standard requires a greater
showing than ‘but for’ causation.” de Bazan v. Sec’y of Health & Human Servs., 539 F.3d
at 1351 (quoting Shyface v. Sec’y of Health & Human Servs., 165 F.3d at 1352).
“However, the petitioner need not show that the vaccine was the sole or predominant
cause of her injury, just that it was a substantial factor.” Id. (citing Walther v. Sec'y of
Health & Human Servs., 485 F.3d 1146, 1150 (Fed. Cir. 2007)). A Judge of the United
States Court of Federal Claims has explained the relationship between “but-for” causation
and “substantial factor” causation in our court’s decision in Deribeaux ex rel. Deribeaux
v. Secretary of Health and Human Services:

       The de Bazan court defined but-for causation as requiring that “the harm be
       attributable to the vaccine to some nonnegligible degree,” and noted that,
       although substantial is somewhere beyond the low threshold of but-for
       causation, it does not mean that a certain factor must be found to have
       definitively caused the injury. Id. [de Bazan v. Sec’y of Health & Human
       Servs., 539 F.3d at 1351] Accordingly, a factor deemed to be substantial is

                                               21
      one that falls somewhere between causing the injury to a non-negligible
      degree and being the “sole or predominant cause.” Id.

      This definition of substantial—somewhere between non-negligible and
      predominant—is applicable to respondent's burden to prove a sole
      substantial factor unrelated to the vaccine. Accordingly, a respondent's
      burden is to prove that a certain factor is the only substantial factor—one
      somewhere between non-negligible and predominant—that caused the
      injury.

Deribeaux ex rel. Deribeaux v. Sec’y of Health & Human Servs., 105 Fed. Cl. 583, 595
(2012), aff’d, 717 F.3d 1363 (Fed. Cir.), reh’g and reh’g en banc denied (Fed. Cir. 2013)
(emphasis in original).

        A petitioner must prove his or her case by a preponderance of the evidence. See
42 U.S.C. § 300aa-13(a)(1)(A). According to the United States Court of Appeals for the
Federal Circuit, the preponderance of evidence standard is “one of proof by a simple
preponderance, of ‘more probable than not causation.’” Althen v. Sec’y of Health &
Human Servs., 418 F.3d at 1279-80 (citing concurrence in Hellebrand v. Sec’y of Dep’t
of Health & Human Servs., 999 F.2d 1565, 1572-73 (Fed. Cir. 1993)); see also W.C. v.
Sec’y of Health & Human Servs., 704 F.3d at 1356 (“In this off-table case, the petitioner
must show that it is ‘more probable than not’ that the vaccine caused the injury.” (quoting
Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1279-80)). A petitioner who meets
this burden is then entitled to recovery under the Vaccine Act, unless the respondent
proves by preponderant evidence that the injury was caused by factors unrelated to the
vaccine. See Stone v. Sec’y of Health & Human Servs., 676 F.3d 1373, 1379-80 (Fed.
Cir. 2012); see also Rus v. Sec’y of Health & Human Servs., 129 Fed. Cl. 672, 680 (2016)
(citing 42 U.S.C. § 300aa-13(a)(1)(B); Shalala v. Whitecotton, 514 U.S. 268, 270-71
(1995)); Walther v. Sec’y of Health & Human Servs., 485 F.3d at 1551. “But, regardless
of whether the burden of proof ever shifts to the respondent, the special master may
consider the evidence presented by the respondent in determining whether the petitioner
has established a prima facie case.” Rus v. Sec’y of Health & Human Servs., 129 Fed.
Cl. at 680 (citing Stone v. Sec’y of Health & Human Servs., 676 F.3d at 1379; de Bazan
v. Sec’y of Health & Human Servs., 539 F.3d at 1353).

       For petitioner to establish a prima facie case, decisions of the Federal Circuit
permit the use of circumstantial evidence, which the court described as “envisioned by
the preponderance standard” and by the vaccine system created by Congress, in which
“close calls regarding causation are resolved in favor of injured claimants” without the
need for medical certainty. See Althen v. Sec’y of Health & Human Servs., 418 F.3d at
1280; see also Cloer v. Sec’y of Health & Human Servs., 654 F.3d 1322, 1332 n.4 (Fed.
Cir. 2011), cert. denied, 566 U.S. 956 (2012); Andreu ex rel. Andreu v. Sec’y of Health &
Human Servs., 569 F.3d at 1379 (“In Althen, however, we expressly rejected the Stevens
test, concluding that requiring ‘objective confirmation’ in the medical literature prevents
‘the use of circumstantial evidence . . . and negates the system created by Congress’
through the Vaccine Act.”) (modification in original); LaLonde v. Sec’y of Health & Human
Servs., 110 Fed. Cl. 184, 198 (2013) (“Causation-in-fact can be established with

                                            22
circumstantial evidence, i.e., medical records or medical opinion.”), aff’d, 746 F.3d 1334
(Fed. Cir. 2014). The Althen court further noted that “the purpose of the Vaccine Act’s
preponderance standard is to allow the finding of causation in a field bereft of complete
and direct proof of how vaccines affect the human body.” Id. (citing Knudsen ex rel.
Knudsen v. Sec’y of Health & Human Servs., 35 F.3d 543, 549 (Fed. Cir. 1994)); see also
W.C. v. Sec’y of Health & Human Servs., 704 F.3d at 1356. When proving eligibility for
compensation for an off-Table injury under the Vaccine Act, however, petitioner may not
rely on her testimony alone. According to the Vaccine Act, “[t]he special master or court
may not make such a finding based on the claims of a petitioner alone, unsubstantiated
by medical records or by medical opinion.” 42 U.S.C. § 300aa-13(a)(1).

      The Federal Circuit in Althen defined a three-prong test which a petitioner must
meet to establish causation in an off-Table injury case:

       To meet the preponderance standard, [petitioner] must “show a medical
       theory causally connecting the vaccination and the injury.” Grant v. Sec'y
       of Health & Humans Servs., 956 F.2d 1144, 1148 (Fed. Cir. 1992) (citations
       omitted). A persuasive medical theory is demonstrated by “proof of a logical
       sequence of cause and effect showing that the vaccination was the reason
       for the injury[,]” the logical sequence being supported by “reputable medical
       or scientific explanation[,]” i.e., “evidence in the form of scientific studies or
       expert medical testimony[.]” Grant, 956 F.2d at 1148. [Petitioner] may
       recover if she shows “that the vaccine was not only a but-for cause of the
       injury but also a substantial factor in bringing about the injury.” Shyface, 165
       F.3d at 1352-53. Although probative, neither a mere showing of a proximate
       temporal relationship between vaccination and injury, nor a simplistic
       elimination of other potential causes of the injury suffices, without more, to
       meet the burden of showing actual causation. See Grant, 956 F.2d at 1149.
       Concisely stated, [petitioner’s] burden is to show by preponderant evidence
       that the vaccination brought about [the] injury by providing: (1) a medical
       theory causally connecting the vaccination and the injury; (2) a logical
       sequence of cause and effect showing that the vaccination was the reason
       for the injury; and (3) a showing of a proximate temporal relationship
       between vaccination and injury.

Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1278 (brackets in original); see
also Deribeaux ex rel. Deribeaux v. Sec’y of Health & Human Servs., 717 F.3d at 1367;
Porter v. Sec’y of Health & Human Servs., 663 F.3d at 1249; Moberly ex rel. Moberly v.
Sec’y of Health & Human Servs., 592 F.3d at 1322; Pafford v. Sec’y of Health & Human
Servs., 451 F.3d at 1355; Capizzano v. Sec’y of Health & Human Servs., 440 F.3d 1317,
1324 (Fed. Cir. 2006); C.K. v. Sec’y of Health & Human Servs., 113 Fed. Cl. 757, 766
(2013).

       With regard to the first Althen prong, “a medical theory causally connecting the
vaccination and the injury,” Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1278,
the Federal Circuit in Althen analyzed the preponderance of evidence requirement as
allowing medical opinion as proof, even without scientific studies in medical literature that

                                              23
provide “objective confirmation” of medical plausibility. Id. at 1278, 1279-80; see also
Shapiro v. Sec’y of Health & Human Servs., 105 Fed. Cl. at 358. In rejecting a requirement
that a claimant under the Vaccine Act prove confirmation of medical plausibility from the
medical community and medical literature, the Althen court turned to the analysis
undertaken in Knudsen ex rel. Knudsen v. Secretary of Health and Human Services, 35
F.3d at 549. See Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1279-80. In
Knudsen ex rel. Knudsen v. Secretary of Health and Human Services, the United States
Court of Appeals for the Federal Circuit wrote, “to require identification and proof of
specific biological mechanisms would be inconsistent with the purpose and nature of the
vaccine compensation program. The Vaccine Act does not contemplate full blown tort
litigation in the Court of Federal Claims.” Knudsen ex rel. Knudsen v. Sec’y of Health &
Human Servs., 35 F.3d at 549. The Federal Circuit stated further:

       [t]he Court of Federal Claims is therefore not to be seen as a vehicle for
       ascertaining precisely how and why DTP and other vaccines sometimes
       destroy the health and lives of certain children while safely immunizing most
       others. This research is for scientists, engineers, and doctors working in
       hospitals, laboratories, medical institutes, pharmaceutical companies, and
       government agencies. The special masters are not “diagnosing” vaccine-
       related injuries. The sole issues for the special master are, based on the
       record evidence as a whole and the totality of the case, whether it has been
       shown by a preponderance of the evidence that a vaccine caused the
       [petitioner’s] injury or that the [petitioner’s] injury is a table injury, and
       whether it has not been shown by a preponderance of the evidence that a
       factor unrelated to the vaccine caused the child's injury. See 42 U.S.C.
       § 300aa-13(a)(1), (b)(1).

Id. (brackets added). The Federal Circuit has also indicated that:

       Although a finding of causation “must be supported by a sound and reliable
       medical or scientific explanation,” causation “can be found in vaccine
       cases…without detailed medical and scientific exposition on the biological
       mechanisms.” Knudsen v. Sec'y of the Dep't of Health & Human Servs., 35
       F.3d 543, 548-49 (Fed. Cir. 1994). It is not necessary for a petitioner to point
       to conclusive evidence in the medical literature linking a vaccine to the
       petitioner's injury, as long as the petitioner can show by a preponderance
       of the evidence that there is a causal relationship between the vaccine and
       the injury, whatever the details of the mechanism may be.

Simanski v. Sec'y of Health & Human Servs., 671 F.3d 1368, 1384 (Fed. Cir. 2012)
(omission in original).

        The second prong of the Althen test requires the petitioner to demonstrate “a
logical sequence of cause and effect, showing that the vaccination was the reason for the
injury” by a preponderance of the evidence. Althen v. Sec'y of Health & Human Servs.,
418 F.3d at 1278; see also Pafford v. Sec’y of Health & Human Servs., 451 F.3d at 1355.
In order to prevail, the petitioner must show “that the vaccine was not only a but-for cause

                                             24
of the injury but also a substantial factor in bringing about the injury.” Althen v. Sec'y of
Health & Human Servs., 418 F.3d at 1278 (quoting Shyface v. Sec’y of Health & Human
Servs., 165 F.3d at 1352). In Capizzano v. Secretary of Health and Human Services, 440
F.3d at 1326, the Federal Circuit stated, “‘[a] logical sequence of cause and effect’ means
what it sounds like – the claimant's theory of cause and effect must be logical. Congress
required that, to recover under the Vaccine Act, a claimant must prove by a
preponderance of the evidence that the vaccine caused his or her injury.” Capizzano v.
Sec'y of Health & Human Servs., 440 F.3d at 1326 (quoting 42 U.S.C. §§ 300aa-11(c)(1)
– 13(a)(1) (2006)); see also Cozart v. Sec’y of Health & Human Servs., 126 Fed. Cl. 488,
498 (2016) (quoting Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1278).

        The third prong of the Althen test requires the petitioner to demonstrate, by a
preponderance of evidence, “a proximate temporal relationship between vaccination and
injury.” Althen v. Sec'y of Health & Human Servs., 418 F.3d at 1278. The United States
Court of Appeals for the Federal Circuit emphasized the importance of a temporal
relationship in Pafford v. Secretary of Health and Human Services, when it noted that,
“without some evidence of temporal linkage, the vaccination might receive blame for
events that occur weeks, months, or years outside of the time in which scientific or
epidemiological evidence would expect an onset of harm.” Pafford v. Sec'y of Health &
Human Servs., 451 F.3d at 1358. Requiring evidence of strong temporal linkage is
consistent with the third requirement articulated in Althen because “[e]vidence
demonstrating petitioner’s injury occurred within a medically acceptable time frame
bolsters a link between the injury alleged and the vaccination at issue under the ‘but-for’
prong of the causation analysis.” Id. (citing Capizzano v. Sec’y of Health & Human Servs.,
440 F.3d at 1326). The Capizzano court further explained,

       [i]f, for example, symptoms normally first occur ten days after inoculation
       but petitioner's symptoms first occur several weeks after inoculation, then it
       is doubtful the vaccination is to blame. In contrast, if symptoms normally
       first occur ten days after inoculation and petitioner's symptoms do, in fact,
       occur within this period, then the likelihood increases that the vaccination is
       at least a factor. Strong temporal evidence is even more important in cases
       involving contemporaneous events other than the vaccination, because the
       presence of multiple potential causative agents makes it difficult to attribute
       "but-for" causation to the vaccination. After all, credible medical expertise
       may postulate that any of the other contemporaneous events may have
       been the sole cause of the injury.

Id. at 1358. 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 at 1352. Determining what constitutes a medically appropriate
timeframe, thus, is linked to the petitioner’s theory of how the vaccine can cause
petitioner’s injury. See id.; see also K.T. v. Sec’y of Health & Human Servs., 132 Fed. Cl.
175, 186 (2017); Shapiro v. Sec’y of Health & Human Servs., 101 Fed. Cl. at 542.

                                             25
       According to the court in Capizzano v. Secretary of Health and Human Services,
evidence used to satisfy one of the Althen prongs may overlap with and be used to satisfy
another prong. Capizzano v. Sec’y of Health & Human Servs., 440 F.3d at 1326 (“We see
no reason why evidence used to satisfy one of the Althen III prongs cannot overlap to
satisfy another prong.”). If a petitioner satisfies the Althen burden and meets all three
prongs of the test, the petitioner prevails, “unless the [government] shows, also by a
preponderance of the evidence, that the injury was in fact caused by factors unrelated to
the vaccine.” Knudsen ex rel. Knudsen v. Sec'y of Health & Human Servs., 35 F.3d at
547 (brackets in original; citation omitted).

        In cases in which a petitioner relies upon expert testimony to prove causation, the
expert testimony must rest upon an objective and reliable scientific basis and must prove
causation to a degree of legal certainty, but not to a medical or scientific certainty. See
Moberly ex rel. Moberly v. Sec'y of Health & Human Servs., 592 F.3d at 1322 (“A petitioner
must provide a reputable medical or scientific explanation that pertains specifically to the
petitioner's case, although the explanation need only be “legally probable, not medically
or scientifically certain.’”); see also Cedillo v. Sec’y of Health & Human Servs., 617 F.3d
at 1339; Terran ex rel. Terran v. Sec’y of Health & Human Servs., 195 F.3d 1302, 1316
(Fed. Cir. 1999), cert. denied, 531 U.S. 812 (2000). While a petitioner may rely solely on
expert testimony, “[a]n expert opinion is no better than the soundness of the reasons
supporting it.” Perreira v. Sec’y of Health & Human Servs., 33 F.3d 1375, 1377 n.6 (Fed.
Cir. 1994). Therefore, a Special Master does not need to credit “expert opinion testimony
that is connected to the existing data or methodology ‘only by the ipse dixit[25] of the
expert,’ or where ‘there is simply too great an analytical gap between the data and the
opinion proffered.’” Jarvis v. Sec’y of Health & Human Servs., 99 Fed. Cl. at 61 (quoting
Cedillo v. Sec’y of Health & Human Servs., 617 F.3d at 1339). The Special Master may
conduct an inquiry into the scientific reliability of expert testimony as may be reasonable
and necessary, and may consider the experts’ credentials when determining the relative
weight to afford opinion testimony. See Terran v. Sec’y of Health & Human Servs., 195
F.3d at 1316; see also Copenhaver v. Sec’y of Health & Human Servs., 129 Fed. Cl. 176,
183 (2014); Tompkins v. Sec’y of Health & Human Servs., 117 Fed. Cl. 713, 719 (2014);
Holmes v. Sec’y of Health & Human Servs., 115 Fed. Cl. 469, 490 (2014); Locane v.
Sec’y of Health & Human Servs., 99 Fed. Cl. 715, 727 (2011), aff’d, 685 F.3d 1375, 1380
(Fed. Cir. 2012).

     I.   The Manner in Which the Special Master Conducted the September 27, 2016
          Hearing Did Not Violate Vaccine Rule 3(b)(2) or Vaccine Rule 8.

      Petitioner argues in her Motion for Review that this court should reverse the
Special Master’s Decision Denying Entitlement because the Special Master violated

25 Ipse dixit is Latin for “he himself said it.” Black's Law Dictionary 956 (10th ed. 2014).
The term is defined as “[s]omething asserted but not proved. . . . The phrase is commonly
used in court decisions analyzing the admissibility of expert testimony. A court may reject
expert-opinion evidence that is connected to existing data only by the expert’s ‘ipse dixit.’”
Id.

                                             26
Vaccine Rules 3(b)(2) and 8, which she alleges resulted in a “fundamental abuse of
petitioner’s right to a full and fair opportunity to present her case.” Petitioner initially argues
that Special Master Corcoran, to whom the case had been reassigned, erred when,
regarding the September 27, 2016 entitlement hearing, he indicated he intended to follow
the January 15, 2014 Order issued by Special Master Moran that the parties’ expert
witness reports would be entered into the record, without the need for oral, direct expert
testimony. Although Special Master Corcoran, in fact, allowed limited, direct, expert
testimony at the September 27, 2016 hearing, petitioner alleges that the limitations were
inappropriate and that the restrictions imposed on the direct testimony by the experts
were “not uniformly enforced” by Special Master Corcoran. Petitioner asserts that
respondent’s expert, Dr. Shinnar, was allowed to give more direct testimony than
petitioner’s expert, Dr. Engstrand. Petitioner claims that because Dr. Engstrand was not
allowed to give full direct testimony at the hearing, it “set up the petitioner to fail by
preventing [Dr. Engstrand] from fully explaining her opinions,” i.e., “her medical theory,
the logical sequence of cause and effect, or the appropriate time period for reactions to
the vaccination to comply with the Althen prongs.” Petitioner argues that the Special
Master’s actions violated Vaccine Rule 3(b)(2) because, pursuant to this rule,
“[p]etitioner’s position is that she has a right to present her expert witness testimony at
the hearing including direct testimony,” and that Dr. Engstrand had insufficient time to
“fully elucidate her opinions.” According to petitioner, it was “unreasonable” for the Special
Master to expect petitioner’s expert to fully explain her theory in written format. 26

       Petitioner also argues in her Motion for Review that the Special Master violated
Vaccine Rule 8, on the grounds that, after the Special Master had elected to hold a
hearing, petitioner had the right to fully examine her witness and petitioner was allegedly
denied this right by the procedures employed by the Special Master. During oral
argument, held on May 31, 2017, this court asked petitioner’s counsel to identify legal
authority in support of this alleged absolute right, and counsel was unable to do so.
Petitioner’s counsel stated: “[The Special Master] can take written testimony if there is no
hearing. If there is a hearing, the rules don’t address that,” and cited Vaccine Rule 8. The
only case law petitioner cites in his brief is Richardson v. Secretary of Health and Human
Services, 89 Fed. Cl. 657 (2009), which, although not helpful to petitioner, is a case in
which a Judge of this court found that a Special Master at a hearing had “failed to

26Petitioner also alleges that “this new rule developed by the special masters, further puts
additional financial burdens on petitioner” because “[t]he rule requires petitioner’s experts
to devote much more time into preparing and drafting their reports then [sic] would take
them to orally explain their opinions at hearing, consequently increasing their retainer
requirements.” In this argument, petitioner and petitioner’s counsel seem to suggest that
a petitioner should prepare a less complete expert report and save a more complete
theory of causation to be presented by the expert on direct examination at the hearing.
The court roundly rejects this theory of how to prepare a case. To proceed in this manner
would automatically place respondent at a disadvantage, with the inability to review
petitioner’s theory of causation in order to be prepared for a response and for the hearing.

                                                27
satisfy . . . fundamental due process requirements.” 27 Richardson v. Sec’y of Health &
Human Servs., 89 Fed. Cl. at 660.28

        In its Memorandum in Response to Petitioner’s Motion for Review, the government
argues that the Special Master is authorized by 42 U.S.C. § 300aa-12(d)(2)(D) and by
Vaccine Rules 8(d) and (e) to direct that written expert reports can serve as direct
testimony, and that the procedures the Special Master followed provided both parties with
a full and fair opportunity to present their cases in furtherance of the goals in Vaccine
Rule 3(b)(2). The government additionally asserts that petitioner’s Motion for Review is
deficient because it fails to specify how her case has been prejudiced by the procedures
the Special Master followed.

        First, Vaccine Rule 3(b) sets forth the Special Master’s “Duties” regarding the
manner in which to conduct the proceedings, emphasizing that proceedings should be
“expeditious, flexible, and less adversarial, while at the same time affording each party a
full and fair opportunity to present its case and creat[e] a record sufficient to allow review
of the special master’s decision.” Vaccine Rule 3(b)(2); see also Campbell ex rel.
Campbell v. Sec’y of Health & Human Servs., 69 Fed. Cl. 775, 778 (2006) (finding that
the concept of “fundamental fairness” incorporated into Vaccine Rule 3(b) “surely entails

27 At oral argument, counsel for petitioner also attempted to assert the Fourth Amendment
of the United States Constitution as a source of petitioner’s alleged denied right to due
process of law, but was unable to articulate the basis for this position and was unable to
cite any case law in support of his baseless Fourth Amendment due process argument.
28 In Richardson, a Judge of this court “conclude[d] that the procedures used by the
Special Master . . . failed to satisfy these fundamental due process requirements,”
referring to Vaccine Rules 3(b)(2) and 8(b)(1). Richardson v. Sec’y of Health & Human
Servs., 89 Fed. Cl. at 660 The Richardson court so found because the Special Master
had “precluded any coherent direct examination” and effectively “functioned as a third
adversary to the proceedings, rather than as a judicial officer” when he repeatedly, and
disproportionately (e.g., 113 interruptions by the Special Master, compared to petitioner’s
counsel’s 25 questions during direct testimony), interrupted the proceedings such that
“the [petitioner’s] witness essentially had to endure two cross-examinations instead of
one,” which the court found “eviscerate[d] the fairness of the proceedings.” Id. at 659. In
Richardson, the Special Master also rejected the testimony of all fact witnesses, making
his decision solely on the written record and “applied every conceivable inference against
Petitioners.” Id. at 659-60. The Richardson court wrote, “[Vaccine Rule 8(c)(1)] permit[s]
a Special Master to propound questions to a witness . . . but not in a way that eviscerates
the fairness of the proceedings.” Id. at 660. By contrast, here, Special Master Corcoran
gave both expert witnesses significant and relatively equal opportunity to summarize their
reports, albeit with shortened expert direct testimony, and allowed each counsel to cross-
examine and re-direct both witnesses. The only time Special Master Corcoran interrupted
a witness was at the beginning of Dr. Shinnar’s testimony when he instructed
respondent’s expert, not petitioner’s, not to give more direct testimony than a brief
summary of his report.

                                             28
notice and an effective opportunity to be heard at a meaningful time and in a meaningful
manner.”); Plavin v. Sec’y of Health & Human Servs., 40 Fed. Cl. 609, 622 (1998) (“The
Vaccine Act contemplates evidentiary flexibility and informality in proceedings. . . . In
addition, ‘[i]n conducting a proceeding on a petition a special master . . . may require the
testimony of any person . . . as may be reasonable and necessary.’” (quoting 42 U.S.C.
§ 300aa-12(d)(3)(B)(iii))).

       Contrary to petitioner’s argument, the procedures followed by the Special Masters
in the present case complied with the discretionary responsibilities outlined in Vaccine
Rule 3(b)(2). Special Master Moran issued his draft Order on December 23, 2013, which
gave advance notice that “the expectation is that the expert’s written report will constitute
the expert’s direct testimony.” The draft Order further explained:

       The purpose of this requirement is two-fold. First, because everyone
       understands that the expert report constitutes the direct testimony, the
       report will be complete. A complete report is likely to present the considered
       views of the expert. Thus, the expert’s opinion will not be based upon an
       oral presentation, during which the expert may not express her (or his)
       opinions as clearly as the expert could have presented them in written
       format. Second, the amount of time spent at hearing will decrease because
       the expert will not need to repeat the content of the report.

This language suggests that Special Master Moran was attempting to fulfill his duty to
“endeavor[] to make the proceedings expeditious, flexible, and less adversarial.” Vaccine
Rule 3(b)(2). Special Master Moran subsequently followed up his draft Order with a final
Order, issued on January 15, 2014, to the same effect. The Special Master, thus, gave
notice to the parties of how the case would proceed well in advance of the filing by both
parties of their expert reports.29 Further, prior to issuing the final Order, Special Master
Moran offered both parties over two weeks to file objections. Petitioner failed, during these
two weeks, to object to the draft or final Orders, but instead waited until January 24, 2014
to ask that the January 15, 2014 final Order be reconsidered, a request Special Master
Moran denied in an Order issued on January 29, 2014.

       At the September 27, 2016 entitlement hearing, however, Special Master Corcoran
ultimately allowed each expert a roughly equal opportunity to briefly, orally summarize his
or her expert report in truncated, direct testimony, in addition permitted each counsel to
cross-examine the other party’s expert, and to re-direct their own experts. Further, Special
Master Corcoran questioned both witnesses himself to be sure he understood their
theories of causation. Petitioner, nonetheless, alleges that

       petitioner’s expert neurologist Dr. Beatrice Engstrand, could not discuss the
       detailed meaning of the medical articles she filed because she was not

29 Petitioner’s brief acknowledges that when the case was transferred to the present
Special Master, petitioner was informed that Special Master Moran’s Order curtailing
direct testimony at the hearing would be followed.

                                             29
       afforded the opportunity to testify directly at the hearing, neither could she
       fully explain her medical theory, the logical sequence of cause and effect,
       or the appropriate time period for reactions to the vaccination to comply with
       the Althen prongs.

Contrary to petitioner’s allegations, in Dr. Engstrand’s first expert report, two subsequent,
supplemental expert reports, and her post-hearing affidavit, as well as during her brief
direct testimony,30 in her much more extensive cross examinations, and in her re-direct
testimony, Dr. Engstrand was given more than sufficient opportunities to address her
reasons and explanation for her theory of causation.

       To the extent petitioner argues that more time for direct testimony would have
given Dr. Engstrand “the opportunity to more fully expound upon her cytokine induced
seizure medical theory,” petitioner’s argument is not supported by the facts of this case.
During the course of the hearing before Special Master Corcoran, he permitted Dr.
Engstrand multiple opportunities to discuss her theory. Moreover, he asked Dr. Engstrand
several times to elaborate on the details of her modified cytokine theory and particularly
why she had changed her theory of causation from the theory included in her first expert
report. Further, not only did Special Master Corcoran permit Dr. Engstrand, prior to the
hearing, to file two supplemental reports in addition to her initial, filed expert report, but,
even after the hearing, Special Master Corcoran permitted Dr. Engstrand to file a
supplementary post-hearing affidavit to “more fully expound upon” her theory, which she
had, by her own admission, modified by the time of the hearing. The record before this
court indicates that the Special Master gave petitioner multiple opportunities to fully
present Dr. Engstrand’s view of causation. Furthermore, Special Master Corcoran offered
a detailed discussion in his final opinion which addressed the evidence upon which Dr.
Engstrand relied to offer her expert opinion. See K.L. v. Sec’y of Health & Human Servs.,
2017 WL 1713110, at *4-6.

        Finally, contrary to petitioner’s allegations, the record before this court contains no
evidence that the procedures followed “were not uniformly enforced” on both parties. The
Special Master does not appear to have given Dr. Shinnar a significantly greater
opportunity at the hearing to summarize his report in the brief direct testimony than he
gave to Dr. Engstrand. In the hearing transcript, Dr. Shinnar’s direct testimony takes up
four pages, each of twenty-five lines, plus ten lines, and Dr. Engstrand’s covers three
pages, each of twenty-five lines, plus eight lines. The method of conducting the
proceedings in K.L.’s case complied with the responsibilities of a Special Master included
as specified in Vaccine Rule 3(b)(2), to “endeavor[] to make the proceedings expeditious,
flexible, and less adversarial,” including by avoiding repetition, “while at the same time
affording each party a full and fair opportunity to present its case.” The Special Master
was not arbitrary and capricious, and did not prevent K.L. from fully explaining her theory
of causation.

30At the September 27, 2016 hearing, petitioner’s counsel directly examined his expert,
Dr. Engstrand, albeit briefly, about her opinions regarding all three of the Althen prongs.

                                              30
        Next, petitioner argues that, under Vaccine Rule 8, “she has a right to present her
expert witness testimony at the hearing including direct testimony.” Vaccine Rule 8
provides the Special Master with broad discretionary authority to “determine the format
for taking evidence and hearing argument based on the specific circumstances of each
case and after consultation with the parties.” Vaccine Rule 8(a). In doing so, the Special
Master “will not be bound by common law or statutory rules of evidence, but must consider
all relevant and reliable evidence governed by principles of fundamental fairness to both
parties.” Vaccine Rule 8(b)(1). According to Rule 8, the Special Master “may conduct an
evidentiary hearing to provide for the questioning of witnesses either by the special
master or by counsel, or for the submission of sworn testimony in written form.” Vaccine
Rule 8(c)(1) (emphasis added).31 The plain language of the Vaccine Act and the Vaccine
Rules allows broad discretion to the Special Master, including the choice of whether or
not to schedule a hearing, and, if so, which witnesses, including the experts, should testify
on direct and/or only on cross examination, in addition to submitting expert reports and
affidavits. Indeed, the Federal Circuit, explicitly, has approved of a Special Master’s
decision to forego any expert testimony and decide a case solely on the written record.
See Burns v. Sec’y of Health & Human Servs., 3 F.3d at 416-17 (finding it was proper for
the Special Master not to hear oral expert medical testimony, after holding an evidentiary
hearing and reviewing the expert reports); see also D’Tiole v. Sec’y of Health & Human
Servs., 132 Fed Cl. 421, 434-35 at *11 (2017) (finding that the Special Master did not
violate Vaccine Rule 3(b) when he or she decided not to hold an evidentiary hearing on
an otherwise fully developed record); Murphy v. Sec’y of Health & Human Servs., 23 Cl.
Ct. 726, 730 (1991) (finding that, if the Special Master finds that the written record is fully
developed, the Special Master may decide the case without an evidentiary hearing,
notwithstanding the desires of one or both of the parties).

31   The relevant underlying statute states:

         (B) In conducting a proceeding on a petition the special master –

                (i) may require such evidence as may be reasonable and necessary,

                (ii) may require the submission of such information as may be
                reasonable and necessary,

                (iii) may require the testimony of any person and the production of
                any documents as may be reasonable and necessary,

                (iv) shall afford all interested persons an opportunity to submit
                relevant written information . . . , and

                (v) may conduct such hearings as may be reasonable and
                necessary.

42 U.S.C. § 300aa-13(12)(B).

                                               31
       In the case before this court, Special Master Corcoran’s instructions to the parties
at the beginning of the September 27, 2016 hearing were:

       [T]he expert testimony, the direct portion of their testimony will be
       considered to have been provided in the form of their expert report or
       reports. What I am going to allow each side to do is to very briefly, in less
       than five minutes, if not quicker, allow the expert to provide the essence of
       what their testimony is going to be or what their report says, and then we
       will go into cross examination and then we’ll have redirect, and then, at that
       time, counsel will have the opportunity to follow up with their expert. That’s
       the process that I’m going to follow today.

Although in advance of the hearing, Special Master Corcoran stated he would follow
Special Master Moran’s Order excluding direct, expert, oral testimony, he ultimately
allowed brief, direct, expert oral testimony. The Special Master also allowed cross
examination, as well as, re-direct examination of both expert witnesses. Moreover, at the
hearing, the Special Master asked each witness multiple, clarifying questions, to better
understand the testimony and the expert reports, which had been submitted for the
record. Finally, the Special Master allowed Dr. Engstrand to file her original expert report
and multiple supplements thereto, including one following the hearing.

        The Vaccine Rules give the Special Master broad discretion to establish the
manner in which evidence will be taken into the record, including the power to “determine
the format for taking evidence and hearing argument based on the specific circumstances
of each case and after consultation with the parties.” Vaccine Rule 8(a). Special Master
Corcoran did not abuse his broad discretion when he permitted only abbreviated direct
oral testimony by the expert witnesses at the September 27, 2016 hearing and by
accepting the experts’ reports and supplemental reports as their primary direct testimony.
As prescribed by Vaccine Rule 8, the previous Special Master “consult[ed] with the
parties” regarding the format for taking evidence at the January 15, 2014 status
conference and through issuance of draft and final Orders. See Vaccine Rule 8(a).
Petitioner’s argument that she had an absolute right to full direct examination of her expert
witness at the hearing and that the failure of the Special Master to do so “set up the
petitioner to fail” because it “prevent[ed] her expert from fully explaining her opinions” is
meritless.

       The court is satisfied that petitioner had a “full and fair opportunity to present [her]
case.” Vaccine Rule 3(b)(2). Contrary to petitioner’s argument, the Special Master acted
within the discretionary authority afforded him by Vaccine Rules 3 and 8. Additionally,
because the Special Master offered both sides essentially equal opportunities, and his
decision considered the evidentiary record in its entirety, his actions were not arbitrary or
capricious, and the procedures he followed did not subject petitioner to any unfair
prejudice. Petitioner, therefore, has failed to demonstrate that the Special Master’s
decision should be reversed as arbitrary and capricious because it failed to provide
fundamental due process to the petitioner.

                                              32
   II.    The Special Master Correctly Applied the Althen Standard to Petitioner’s Case.

        Petitioner’s Motion for Review also alleges that the Special Master erred in finding
that K.L. had not carried her burden of proof to meet all three Althen prongs. Petitioner
claims that the Special Master improperly applied a heightened burden of proof,
effectively requiring petitioner to prove her case with scientific certainty, rather than
applying the preponderance of the evidence standard for causation, as required by the
Vaccine Act and Althen v. Secretary of Health and Human Services, 418 F.3d at 1278.
Petitioner further argues that, in any event, petitioner met her burden of proof satisfying
all three prongs of the Althen standard. As noted above, for a non-Table injury such as
petitioner alleges, petitioner carries the burden to satisfy all three elements established
by the Federal Circuit in Althen, namely: “(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.” Id. The court notes that, at the oral argument
before this court on May 31, 2017, counsel for petitioner admitted that the Special Master
correctly had applied Althen when petitioner’s counsel stated that “the three prongs were
appropriately applied.”

        Petitioner states that the Special Master improperly raised petitioner’s burden of
proof because he allegedly “review[ed] the evidence ‘through the lens of the
laboratorian,’” quoting Andreu ex rel. Andreu v. Secretary of Health and Human Services,
569 F.3d at 1378-79, instead of applying the preponderance of the evidence standard
prescribed in Althen. Although petitioner’s brief acknowledges that the Special Master
“cit[ed] numerous precedents saying the special masters must be careful not to increase
petitioners [sic] burden of proof,” petitioner’s counsel argues, however, that the Special
Master’s analysis of the evidence effectively required the petitioner to prove her causation
theory with scientific certainty. Petitioner alleges that the Special Master “disallowed
[petitioner’s] claim because of its novelty and the fact that no specific scientific study
conforms to the specific facts of this case” in violation of the Althen test, arguing in a
footnote that the fact that petitioner’s causation theory is scientifically unproven should
not preclude her from compensation under the Vaccine Act.

        Although petitioner is correct that the Special Master may not raise a petitioner’s
burden of proof to one of “scientific certainty,” this does not lessen petitioner’s burden to
prove a plausible theory of causation supported by reliable scientific evidence. See
Andreu ex rel. Andreu v. Sec’y of Health & Human Servs., 569 F.3d at 1379 (“Although . . .
a claimant need not produce medical literature or epidemiological evidence to establish
causation under the Vaccine Act, where such evidence is submitted, the special master
can consider it in reaching an informed judgment as to whether a particular vaccination
likely caused a particular injury.” (citations omitted)); Capizzano v. Sec’y of Health &
Human Servs., 440 F.3d at 1327 (“The proper inquiry is whether a petitioner in an off-
Table injury case establishes a logical sequence of cause and effect . . . by a
preponderance of the evidence.”(citations omitted)); Knudsen ex rel. Knudsen v. Sec’y of
Health & Human Servs., 35 F.3d at 548-49 (“The determination of causation in fact under
the Vaccine Act involves ascertaining whether a sequence of cause and effect is ‘logical’
and legally probable, not medically or scientifically certain.” (citations omitted)). The

                                             33
Federal Circuit has found that it is not error for a Special Master to consider the medical
literature offered by an expert witness in the context of a petitioner’s alleged injury and
after review find it does not support the petitioner’s theory of causation, so long as the
Special Master provides logical reasoning for finding certain articles unreliable. See
Cedillo v. Sec’y of Health & Human Servs., 617 F.3d at 1345-46; see also K.T. v. Sec’y
of Health & Human Servs., 132 Fed. Cl. 175, 186 (2017) (finding that the Special Master
was not arbitrary or capricious when he considered the reliability and persuasiveness of
scientific literature on which the experts relied “in evaluating the reliability of the expert’s
testimony,” and that the literature petitioner cited did not persuasively support petitioner’s
theory of causation, nor did his analysis constitute a “heightened legal standard”).

        In the present case, Special Master Corcoran neither required petitioner to prove
her case with scientific certainty, nor did he require petitioner to produce a scientific study
that directly conformed to petitioner’s causation theory. Special Master Corcoran’s
decision does not mention the “novelty” of petitioner’s theory of causation, nor does it
state that his decision was in any way related to the fact that no scientific study conforms
to the facts of petitioner’s case. Rather, the Special Master concluded that the literature
petitioner cited “did not assist [her] case,” because “much of the literature [Dr. Engstrand]
offered either involved autoimmune forms of epilepsy (which are irrelevant under the facts
of the case), different vaccines, or involved the relationship between the HPV vaccine
and febrile seizures, which K.L. unquestionably never experienced,” and, thus, were
distinguishable from K.L.’s case. K.L. v. Sec’y Health & Human Servs., 2017 WL
1713110, at *14. Special Master Corcoran concluded that petitioner had failed to carry
her burden of proof because “the weight of evidence does not support Petitioner’s
causation theory and there is insufficient evidence to support an award of compensation,”
not because petitioner’s causation theory lacked scientific certainty. Id. at *17.

        Special Master Corcoran also correctly applied the Althen standard to the facts of
petitioner’s case. The Special Master began his opinion by noting that he was applying
Althen to petitioner’s case, and acknowledging that, “[i]n attempting to establish an
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.” K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at *10. The Special
Master’s opinion went on to explain and apply each prong of Althen to petitioner’s case,
specifically quoting the same language as petitioner did from Andreu ex rel. Andreu v.
Secretary of Health and Human Services, 569 F.3d at 1377, and further noting that a
Special Master “must take care not to increase the burden placed on petitioners in offering
a scientific theory linking vaccine to injury.” Id. at *13-14 (citation omitted). Specifically, at
the end of this section of his opinion, which Special Master Corcoran titled “Althen Prong
One,” id. at *13, he concluded:

       Vaccine Act claimants are not required to prove a causation theory to a
       scientific certainty, but the theory must be based on ‘sound and reliable
       medical or scientific explanation.’ Knudsen [v. Sec’y of Health & Human
       Servs.], 35 F.3d at 548. I do not find that Petitioner has satisfied this
       standard.

                                               34
Id. at *16. Furthermore, in the next section of his opinion, titled “Althen Prongs Two and
Three,” the Special Master analyzed K.L.’s medical records and doctors’ visits, and
determined that “K.L. has not successfully demonstrated with preponderant evidence that
the HPV vaccine did cause her initial seizure as alleged, and thus has not satisfied the
second Althen prong.” Id. With respect to the third Althen prong, the Special Master noted
that its “[r]esolution . . . [is] less easily accomplished,” but determined that the evidence
petitioner had presented on this prong did not “constitute particularly robust support for
Petitioner’s proposed timeframe,” and, even “were [the Special Master] to find that the
balance of evidence on this matter barely favored K.L., that determination would not alter
[the Special Master’s] ultimate decision about causation, because Petitioner’s causation
theory itself is too deficient, and unsupported by the actual medical history.” Id. at *17.
The record before the court establishes that the Special Master analyzed petitioner’s case
under the correct legal standard.

        Petitioner’s Motion for Review also asserts that the Special Master “failed to
considered [sic] the relevant evidence of [sic] record, failed to draw plausible inferences
from such evidence or failed to articulated [sic] a rational basis for the decision.” Petitioner
argues that the Special Master’s reading of the record was arbitrary and capricious
because he improperly “discounted,” “misinterpreted,” and/or did not discuss several of
the studies cited by petitioner’s expert, which allegedly supported her theory. At oral
argument, petitioner’s counsel again asserted that the Special Master’s decision was
arbitrary and capricious “primarily because of the way he reviewed some of the medical
articles.” In response, the government argues that “[f]inding petitioner’s evidence
unpersuasive does not mean that the Special Master misread the evidence or imposed a
higher burden on petitioner than the law requires.”

        With respect to petitioner’s argument that Special Master Corcoran “discounted”
certain evidence, this court finds that the Special Master was not arbitrary or capricious
because, based on his final opinion, he appears to have considered the relevant evidence
in the record, and made reasonable determinations regarding the scientific reliability of
the evidence offered by both parties. According to the relevant statute, the Special Master
is required to weigh and consider “all . . . relevant medical and scientific evidence
contained in the record,” including evidence related to the petitioner’s medical condition.
42 U.S.C. § 300aa-13(b)(1). The Vaccine Act further specifies that the evidence the
Special Master must consider, “in addition to all other medical and scientific evidence
contained in the record,” includes “any diagnosis, conclusion, [or] medical judgment, . . .
which is contained in the record regarding the nature, causation, and aggravation of the
petitioner’s illness, disability, injury, condition, or death . . . and the results of any
diagnostic or evaluative test which are contained in the record and the summaries and
conclusions.” 42 U.S.C. § 300aa-13(b)(1)(A)-(B). After considering the relevant medical
and scientific evidence in the record, the Special Master has discretion to determine the
relative weight to give to evidence in the record, provided he or she offers a rational basis.
See Andreu ex rel. Andreu v. Sec’y of Health & Human Servs., 569 F.3d at 1379 (finding
that the Special Master may make a determination of witness credibility to determine the
weight oral testimony should be afforded in relation to contemporaneous medical
records); Capizzano v. Sec’y of Health & Human Servs., 440 F.3d at 1326 (finding the
Special Master erred when he did not consider the diagnosis of the treating physician,

                                              35
although the treating physician had affirmatively concluded the vaccine caused
petitioner’s injury); Burns v. Sec’y of Health & Human Servs., 3 F.3d at 417 (finding that
the Special Master has discretion to determine whether to afford greater weight to
contemporaneous medical records than to other evidence, so long as the decision is
based on a rational basis); Cucuras v. Sec’y of Health & Human Servs., 993 F.2d 1525,
1528-29 (Fed. Cir. 1993) (finding that when contemporaneous medical records conflict
with later oral testimony, the Special Master was not arbitrary or capricious when he relied
on the medical records to find that petitioner failed to satisfy her burden of proof).

       Petitioner’s motion specifically alleges that the Special Master “apparently did not
review numerous exhibits, including Exhibit 31, Exhibit 33, and Exhibit 37.” Dr.
Engstrand’s third expert report, Exhibit 31, however, was explicitly discussed in the
Special Master’s decision, which states, “[i]n the Spring of 2015, Dr. Engstrand filed her
third report, which mainly sought to rebut points made by Respondent’s expert, Dr.
Shinnar, in his report. She maintained that autoimmune-related epilepsy was more
common than Dr. Shinnar allowed, and that it could manifest without evidence on an EEG
and without a prior or concurrent fever.” K.L. v. Sec’y of Health & Human Servs., 2017
WL 1713110, at *5. The Special Master goes on to describe the literature cited by Dr.
Engstrand in her third report, which included Exhibits 33 and 37. Thus, petitioner’s
argument that the Special Master failed to consider these exhibits is incorrect.

        Petitioner also objects to the Special Master’s treatment of the Li study, attached
to Dr. Engstrand’s affidavit filed on November 4, 2016 after the September 27, 2016
hearing, arguing that the Li study “specifically support[s]” and “confirm[s]” Dr. Engstrand’s
theory, “despite the special master misinterpreting it.” Petitioner alleges in a separate
section of the brief that “the special master simply emphasized a conclusory statement in
the article discussing cytokine activation by seizures, without reviewing the details of the
article which clearly shows that cytokines can indeed cause seizures.” It remains unclear
whether petitioner argues that the Special Master failed to consider the Li study entirely,
or that the Special Master failed to give the article sufficient weight. Both of these
allegations are specious, because Special Master Corcoran, in fact, referenced and
analyzed the Li study two separate times in his opinion, including an in-depth analysis
that quoted directly from the article. See id. at *6, 14. In the first instance, the Special
Master’s decision stated:

       The authors of [the] Li [study] reviewed studies involving cytokines’s role in
       epilepsy. Li concluded that an array of different cytokines were involved –
       but more importantly (for present purposes), that the cytokines were
       activated only after the patient had suffered a seizure, as opposed to
       causing them, and it could not be fully ascertained in any event whether
       post-seizure cytokines exacerbated seizure activity. Li at 256 (“[cytokines]
       are activated by seizures, but their precise role in epilepsy is not yet clear”).
       (emphasis in original).

Id. at *6. In the second instance, the Special Master determined that the Li study “speaks
more of the causative effect seizures have on the upregulation of cytokines than the other

                                              36
way around, thus further undermining Dr. Engstrand’s efforts to restore credibility to her
theory.” Id. at *14.

        Moreover, a Special Master need not discuss in his or her final decision every
piece of medical literature a petitioner files or references, and failing to discuss every
piece of evidence will not alter the presumption that a Special Master has considered the
entire record in his or her decision to grant or deny compensation. See Moriarty v. Sec’y
of Health & Human Servs., 844 F.3d 1322, 1328 (Fed. Cir. 2016) (“We generally presume
that a special master considered the relevant record evidence even though he does not
explicitly reference such evidence in his decision.”). Therefore, the fact that Special
Master Corcoran did not discuss every piece of evidence submitted into the record in his
decision does not, in and of itself, constitute reversible error. In addition, petitioner has
not identified a relevant, critical item of evidence in the record which was not addressed
by the Special Master.

        Furthermore, the level of scrutiny with which the Special Master reviewed the
scientific studies the parties produced was appropriate. The Special Master is required to
“consider all relevant and reliable evidence,” Vaccine Rule 8(a), specifically, any medical
records or reports “contained in the record regarding the nature, causation, and
aggravation of the petitioner’s . . . injury” and “all other relevant medical and scientific
evidence contained in the record.” 42 U.S.C. § 300aa-13(1). Moreover, if the Special
Master considers certain items of medical evidence, but ultimately deems them
unreliable, that does not constitute reversible error. See Cedillo v. Sec’y of Health &
Human Servs., 617 F.3d at 1345-46 (no error found when the Special Master found one
study petitioner cited unreliable because it was inconclusive, and found another
insufficiently detailed in methodology and explanation of findings); see also Hines v. Sec’y
of Health & Human Servs., 940 F.2d at 1527 (finding no error when the Special Master
considered the entire record, although he did not give certain evidence “the controlling
weight [the petitioner] urge[d] he should have”). As the factfinder, the Special Master has
discretion to make determinations regarding the credibility of all the information provided
orally and in writing by fact and expert witnesses, whether they testify in person at a
hearing or submit reports or affidavits for the record. This discretion includes review of
the medical literature submitted in support of a party’s causation theories. See LaLonde
v. Sec’y of Health & Human Servs., 746 F.3d at 1340-41 (finding no error when petitioner’s
expert posited a number of theories, but the Special Master found them unpersuasive
because the theories were not supported by peer-reviewed medical literature).

        In the present case, the Special Master considered and discussed each of Dr.
Engstrand’s four filed reports, Dr. Shinnar’s reports, the experts’ testimony at the hearing
and the parties’ arguments. In his opinion, the Special Master found the support for Dr.
Engstrand’s theory limited, stating: “[b]eyond Dr. Engstrand’s qualifications, there is the
issue of the reliability of the scientific basis for Petitioner’s theory. While the individual
articles offered proved reasonable and reliable individually, taken as a whole they do not
assist Petitioner’s case.” K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at
*14. By contrast, Special Master Corcoran found the literature Dr. Shinnar produced more
persuasive. The Special Master stated in his decision:

                                             37
       Respondent, by contrast, offered far more reliable and credible medical and
       scientific articles suggesting the HPV vaccine would not likely cause injuries
       of the kind experienced by K.L. Studies like Arnheim-Dahlstrom were more
       scientifically reliable (both given the larger population groups studied, as
       well as the fact that they involved observed cases rather than simply
       reported reactions) and more persuasively demonstrated no link between a
       number of neurological events, including epilepsy, and receipt of the HPV
       vaccine.

Id. at *15. From the opinion he issued, it is clear that the Special Master reviewed the
medical literature submitted by both Dr. Engstrand and Dr. Shinnar, and the Special
Master explained why he found that the studies Dr. Engstrand cited were either
insufficiently related to petitioner’s case or less scientifically reliable than those Dr.
Shinnar cited. Contrary to petitioner’s allegation that Special Master Corcoran
“discounted” or “ignored” certain evidence, the Special Master stated in his decision that
he had reviewed all evidence in the record in making his decision. See id. at *1 (“After
considering the record as a whole, and for the reasons explained below, I find that
Petitioner has failed to carry her burden in establishing causation, and therefore is not
entitled to compensation under the Vaccine Program.”). In the decision he laid out a
thorough discussion and analysis of the evidence and the reasoning for his conclusions.
The court finds that the Special Master did not act arbitrarily or capriciously and properly
exercised his discretion.22

        Regarding petitioner’s argument that the Special Master “misinterpreted” certain
evidence, petitioner appears specifically to highlight and object to the limited weight the
Special Master gave to the Li article. At oral argument before this court, petitioner’s
counsel asserted that the Special Master had not “read the Li article thoroughly” because
“there’s a specific part of the Li article that addresses IL-1 beta.” The thoroughness of the
Special Master’s decision and the fact that Dr. Engstrand herself abandoned the
interleukin-1 beta theory during her testimony both demonstrate that petitioner’s
allegation is not supported by the record. Likewise, although counsel asserted that “the
[Li] article says that the balance of the studies they looked at showed an increase in
seizure activity,” the Li study actually concludes:

22 Petitioner’s reliance on Moriarty v. Secretary of Health and Human Services, 844 F.3d
1322, cited to support her assertion that a Special Master committed reversible error
when he allegedly failed to consider the entirety of the record is misplaced. In Moriarty,
the Federal Circuit determined that “[t]here is thus no indication that the special master
considered [petitioner’s expert’s] written testimony in his second report and the articles
cited therein, and there is, in fact, an affirmative indication that he did not do so.” Whereas
the Special Master in Moriarty explicitly stated in his decision that he had not included
certain of the expert’s evidence in his analysis of petitioner’s claim for compensation,
Special Master Corcoran plainly considered Dr. Engstrand’s oral and written testimony,
as well as the articles she provided to the court. See K.L. v. Sec’y of Health & Human
Servs., 2017 WL 1713110, at *14-15.

                                              38
       A growing body of evidence suggests that there is an array of cytokines
       involved in epilepsy. These substances are activated by seizures, but their
       precise role in epilepsy is not yet clear . . . . Levels of these substances
       increase quickly after either generalized tonic-clonic or complex partial
       seizures . . . Seizures not only induce the expression of cytokines in the
       brain but also change peripheral cytokine levels.

See Gang Li et al., Cytokines and Epilepsy, 20 Seizure 249, 253 (emphasis added).
Special Master Corcoran provided a rational basis for the lower evidentiary weight he
gave the Li study, based on the study itself and the evidence in the record, when he stated
that the Li study “speaks more of the causative effect seizures have on the upregulation
of cytokines than the other way around, thus further undermining Dr. Engstrand’s efforts
to restore credibility to her theory after abandoning the opinion she initially offered in her
first submitted expert report about the role of the IL-beta [sic] cytokine.” K.L. v. Sec’y of
Health & Human Servs., 2017 WL 1713110, at *14.

        Petitioner additionally alleges that the Special Master acted arbitrarily and
capriciously when, according to petitioner, he gave “little weight” to the fact that
“numerous treating physicians considered the HPV vaccine to be a possible causative
agent in their differential diagnosis.” Petitioner’s argument lacks merit on multiple
grounds. First, by statute, the Special Master is not bound by “[a]ny such diagnosis,
conclusion, judgment, test result, report, or summary” that is “contained in the record
regarding the nature, causation, and aggravation of the petitioner’s illness,” but rather has
the discretion to “evaluat[e] the weight to be afforded to any such diagnosis” in the record,
in light of “the entire record and the course of the injury, disability, illness, or condition.”
42 U.S.C. § 300aa-13(1). Thus, Special Master Corcoran was not required to conclude
that the Gardasil vaccination caused petitioner’s epilepsy simply because it was noted in
physicians’ notes in the records, and in petitioner’s case, only as a possible cause.
Rather, the Special Master’s decision reflects that he considered the entire record,
including the medical records which recorded the progression of K.L.’s symptoms and
illness over time, the opinions and the diagnoses of her treating physicians, including of
Dr. Poduri, who was also an epilepsy specialist, as well as the opinions of the parties’
expert witnesses.

       Second, petitioner’s brief asserts, “[t]he diagnosis of treating physicians is entitled
to some weight,” citing to Andreu ex rel. Andreu v. Secretary of Health and Human
Services, 569 F.3d at 1367, and Capizzano v. Secretary of Health and Human Services,
440 F.3d at 1326. While petitioner’s statement of the law is correct, the cases petitioner
cites do not assist petitioner. In both Andreu and Capizzano, the treating physician
unequivocally stated that the vaccine was the cause of petitioner’s injury and the treating
physician’s conclusion was undisputed by the government’s witness. See Andreu ex rel.
Andreu v. Sec’y of Health & Human Servs., 569 F.3d at 1376; Capizzano v. Sec’y of
Health & Human Servs., 440 F.3d at 1326. In the current case, in contrast to the facts in
Andreu and Capizzano, the record before the court does not contain any conclusive
statements by any of the petitioner’s treating physicians that indicate that the Gardasil
vaccination was the cause of petitioner’s epilepsy. Instead, none of K.L.’s treating
physicians concluded with any certainty that the vaccine was the causative agent. The

                                              39
record before the court demonstrates that petitioner’s treating physicians simply made
note of K.L’s recent HPV vaccine in K.L.’s medical history, and when any relationship
between Gardasil and her seizures was indicated, it was in purely speculative terms. For
example, at the time of K.L.’s first emergency room visit, her medical records noted that
her recent HPV vaccine was one among several “potential contributors” for her first
seizure. Similarly, the medical record from her February 12, 2010 treatment at FAHC
states: “At transfer the cause of her seizure was thought to be multifactorial with potential
contributors including a mild URI, OTC pharmacotherapy with benadryl and sudafed, and
recent HPV vaccine administration.” Dr. Volansky’s notes from February 15, 2010 state:
“Assessment: seizures, unclear etiology, may be new onset epilepsy, may have been
effect of recent Gardasil and/or decongestants.” Dr. Kalsner’s notes from March 22, 2010
state: “Of note, she did receive the Gardasil vaccine two days prior to the first seizure. It
was her third in a series of vaccinations.” Dr. Poduri’s notes from June 6, 2010 state: “She
had also notably had her Gardasil vaccination two days prior to the first seizure.” Dr.
Volansky’s notes from June 22, 2010, state: “There was some concern about having
Gardasil vaccination, third dose, 2 days prior to having her first seizure onset and maybe
that indicates the seizures should improve; however, would continue antiseizure
medication for a total duration of 2 years and then gradually try to taper it off.” As the
Federal Circuit determined in Moberly v. Secretary of Health and Human Services, if
contemporaneous physician’s notes are “all speculative,” the Special Master is permitted
to find that such evidence is not dispositive. See Moberly ex rel. Moberly v. Sec’y of Health
& Human Servs., 592 F.3d at 1323-25 (finding that speculative notations by treating
physicians were properly not dispositive on causation because “[while] several of
petitioner’s treating physicians noted the temporal relationship between [petitioner’s]
vaccination and petitioner’s initial brief seizures, none ever offered a solid statement
that . . . [the] vaccination caused probably petitioner’s condition”); see also Cedillo v.
Sec’y of Health & Human Servs., 617 F.3d at 1348 (“The Special Master clearly
articulated why he declined to afford significant weight to the notations made by
[petitioner’s] treating physicians, and we see no error in his treatment of that evidence.”).

       Finally, petitioner’s arguments overlook the fact that Dr. Poduri was one of K.L.’s
treating physicians, who had multiple appointments with petitioner, conducted a review of
a detailed MRI study, and conducted a careful analysis of her medical history. Dr. Poduri
diagnosed K.L. with idiopathic epilepsy and did not attribute her seizures to Gardasil. The
Special Master did not err when he gave greater weight to Dr. Poduri and to the expert
report of Dr. Shinnar.

        Petitioner also argues in her brief, with little elaboration, that the Special Master
erred because he did not address the “flaws” in the testimony of respondent’s expert, Dr.
Shinnar, but did so for petitioner’s expert, Dr. Engstrand. According to petitioner,
“[n]umerous critical comments of Dr. Engstrand appear in the Decision, without
corresponding critical analysis of Dr. Shinnar.” Petitioner alleges that Dr. Shinnar’s
testimony and report were unreliable because they contained “many errors,” although
petitioner fails to specify any particular errors in her filings before this court.32 Petitioner

32  K.L.’s Motion for Review simply referenced Petitioner’s post-hearing brief, previously
filed with Special Master Corcoran on November 14, 2016. During oral argument before
                                              40
also argues that the Special Master erred when he “questioned the ability of Dr. Engstrand
to even testify concerning her medical theory because she did not have ‘specialized
expertise in the condition of epilepsy’ even though she is a highly qualified and
experienced neurologist.”

        Contrary to petitioner’s allegations, Special Master Corcoran did not treat the
parties’ experts disparately. Special Master Corcoran permitted both expert witnesses the
opportunity to make clarifications in their testimonies at the September 27, 2016 hearing,
and he directed clarifying questions to each witness. Additionally, after Dr. Engstrand
abandoned her first theory of causation and offered a modified theory at the September
27, 2016 entitlement hearing, Special Master Corcoran permitted her to file a post-hearing
affidavit to support her new theory, which he specifically discussed in his opinion. See
K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at *6. In addition, Special
Master Corcoran separately analyzed the articles cited by both experts in similar terms.
See, e.g., id. at *6 (“Dr. Engstrand offered an article that she represented further
supported the possibility of afebrile seizures following the HPV vaccine . . . . [The]
Crawford [study], like the Valencian Article, involved a retrospective study of passive
surveillance reporting of alleged vaccine adverse events, here based on the HPV
vaccine’s administration in Australia to young females.”); id. at *8 (“Dr. Shinnar opined
that the HPV vaccine could not affirmatively be linked to epilepsy. In support, he cited a
large population study of young girls in Denmark and Sweden . . . . That study found no
increased risk for autoimmune or neurological events among the nearly 300,000 patients
who received multiple doses of the HPV vaccine.”).

        Petitioner’s argument that the Special Master erred by questioning Dr. Engstrand’s
qualifications, but not Dr. Shinnar’s, fails for several reasons. Petitioner has the burden
of proof to establish causation. See 42 U.S.C § 300aa-13(a). Petitioner’s expert, Dr.
Engstrand, ultimately offered a causation theory that relied on an immunological
mechanism and, logically, the Special Master compared it to the evidence Dr. Shinnar
offered, in part, based on their relative expertise in immunology. See Milik v. Sec’y of
Health & Human Servs., 822 F.3d 1367, 1381-82 (Fed. Cir. 2016) (finding that the Special
Master did not act arbitrarily and capriciously when determining that the government
expert’s specific medical qualifications made his testimony more reliable than that of
petitioner’s expert); Porter v. Sec’y of Health & Human Servs., 663 F.3d at 1250 (“[T]his
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.”). In doing so, Special Master Corcoran acted within his proper discretion. The
credibility of an expert witness is an appropriate matter for the Special Master to consider,
given the importance of expert testimony in a petitioner’s ability to carry his or her burden
of proof when alleging a non-Table injury. See, e.g., Cedillo v. Sec’y of Health & Human
Servs., 617 F.3d at 1347 (finding no error when the Special Master determined an expert
witness lacked credibility when the Special Master explained his reason for so

this court on May 31, 2017, when prompted by the court, petitioner’s counsel conceded
that of the four alleged “flaws,” one was “minor” and he was unable to find support in the
record for the others.

                                             41
determining); Hazlehurst v. Sec’y of Health & Human Servs., 604 F.3d at 1349-50 (finding
it was within the Special Master’s discretion to admit and assess the reliability of expert
testimony); H.L., on Behalf of A.I., v. Sec’y of Health & Human Servs., 129 Fed. Cl. 169,
175 (2016) (finding no error for the Special Master to find the government’s witness more
credible than petitioner’s after he “thoroughly reviewed the record, expert testimony, and
the articles each expert cited”). Because a Special Master acts within his discretion when
he or she makes determinations regarding the credibility of any witness, including an
expert witness, it was proper for Special Master Corcoran to consider the credentials of
the expert witnesses in relation to the causation theories they posited and in relation to
each other’s expertise. So long as the Special Master provides a reasonable explanation
in his opinion to show how he reached his conclusions regarding an experts’ credibility,
such credibility determinations will survive review. See, e.g., Broekelschen v. Sec’y of
Health & Human Servs., 618 F.3d at 1347 (finding no error when the Special Master
assessed the credibility of experts and found the government’s more persuasive, and
included a reasoned explanation in the opinion).

       Special Master Corcoran’s decision noted that Dr. Engstrand is a general
neurologist, not an immunologist or epileptologist, and that Dr. Engstrand relied on an
immunological mechanism which linked the Gardasil vaccine to petitioner’s injury and a
rare form of epilepsy based on an immunological mechanism, but that she did not have
the relevant specialized expertise. See K.L. v. Sec’y of Health & Human Servs., 2017 WL
1713110, at *14. Special Master Corcoran stated:

       Dr. Engstrand is not an immunologist—although neither is Dr. Shinnar, for
       that matter. However, this lack of specific expertise on a matter relevant to
       the resolution of the case cuts more against Petitioner than Respondent,
       since Petitioner bears the initial, and ultimate, burden of proof.

Id. at *4 n.12. Special Master Corcoran found that the experts’ respective areas of
expertise cut against Dr. Engstrand, because her causation theory incorporated and
required specialized knowledge of immunology, and in favor of Dr. Shinnar, whose
alternative theory of causation was narrowly focused on epilepsy. Id. at *15. Contrary to
what petitioner argues, the Special Master did not question Dr. Engstrand’s qualifications
as a neurologist, but rather her lack of qualifications as an immunologist. The Special
Master expressed doubt as to the credibility of her expertise, specifically as it related to
her theory of causation in K.L.’s case, which linked the Gardasil vaccine to petitioner’s
injuries, based on an immunological mechanism, and on her selection and discussion of
relevant medical literature. Id. at *14-15. A Special Master may compare the evidence
offered by each side’s expert and make a decision “based on the credibility of the experts
and the relative persuasiveness of their competing theories.” Broekelschen v. Sec’y of
Health & Human Servs., 618 F.3d at 1347 (quoting Lampe v. Sec’y of Health & Human
Servs., 219 F.3d at 1362); see also Milik v. Sec’y of Health & Human Servs., 822 F.3d at
1381-82 (finding that the Special Master was not arbitrary and capricious when he
determined that the government’s expert’s specific medical qualifications made his
testimony more reliable than testimony of petitioner’s expert); Porter v. Sec’y of Health &
Human Servs., 663 F.3d at 1250 (“[S]pecial masters are expected to consider the
credibility of expert witnesses in evaluating petitions for compensation under the Vaccine

                                            42
Act.”); Moberly ex rel. Moberly v. Sec’y of Health & Human Servs., 592 F.3d at 1325-26
(“[a]ssessments as to the reliability of expert testimony often turn on credibility
determinations,” and the Special Master may analyze the credibility of experts);
Copenhaver v. Sec’y of Health & Human Servs., 129 Fed. Cl. 713, 7139 (2014) (finding
that Special Masters may consider the expert’s credentials when determining the relative
weight to afford opinion testimony). Moreover, a Special Master’s credibility findings are
“virtually unchallengeable on appeal.” Broekelschen v. Sec’y of Health & Human Servs.,
618 F.3d at 1347 (quoting Lampe v. Sec’y of Health & Human Servs., 219 F.3d at 1362);
see also Cedillo v. Sec’y of Health & Human Servs., 617 F.3d at 1347 (“Under the Vaccine
Act, Special Masters are accorded great deference in determining the credibility and
reliability of expert witnesses.”). This court, therefore, finds that Special Master Corcoran
acted reasonably and within his discretion when he considered Dr. Engstrand’s relative
qualifications and the literature she included as part of her submissions in support of
petitioner’s theory, in comparison to the relative weight he gave to Dr. Shinnar’s
qualifications, expert report, and testimony, which were offered as a rebuttal to petitioner’s
theory.

        Petitioner also argues that, based on the record before the Special Master,
including Dr. Engstrand’s expert opinion and the literature offered by petitioner’s expert,
she met her burden of proof under the Althen test and that the Special Master’s failure to
so find was in error. She asserts, again, as part of this argument, that the Special Master
raised her burden of proof and that she should not be denied compensation merely
because her theory is novel and “no specific scientific study conforms to the specific facts
of this case.” The government disagrees, arguing that petitioner failed to meet her burden
of proof under Althen and did not prove, by a preponderance of the evidence, that the
Gardasil vaccination caused her injuries. Respondent asserts that “the Special Master’s
conclusion was based on a thorough review of the evidence and is supported by both
plausible inferences and a rational basis,” so it should not be overturned.

       Petitioner first argues that she satisfied her burden under prong one of the Althen
test by showing a plausible theory of causation. Unfortunately for petitioner, her assertion
that she has met Althen prong one with “clear plausibility” by showing a mechanism of
causation that is “supported by credible medical studies” is based on a theory of causation
that petitioner’s own expert abandoned when pressed at the September 27, 2016 hearing.
Even during oral argument before this court on May 31, 2017, petitioner’s counsel
asserted that the interleukin-1 beta theory was “Dr. Engstrand’s entire theory.” Moreover,
the brief submitted by petitioner’s counsel argues:

       Dr. Engstrand has stated that K.L. suffered from an autoimmune reaction
       stimulated by the HPV vaccine which caused release of cytokine interleukin
       1 beta in the course of the immune response to the vaccine (the infectious
       agent), which in turn triggered a cluster of afebrile convulsions or
       seizures . . . .

As noted above, at the September 27, 2016 hearing before the Special Master, however,
when asked about her interleukin-1 beta theory, Dr. Engstrand responded: “I’m not sure
it’s Interleukin-1 beta . . . the more I read about it and reread all the papers again, it is the

                                               43
cytokine — I’m not certain which cytokine — that sets up an inflammatory reaction in K.L.”
Not only did petitioner’s own expert abandon the original theory of causation that
petitioner’s counsel on behalf of petitioner asserts in the Motion for Review, the Special
Master also found that the theory was unsupported by K.L.’s medical records or by any
of the scientific literature petitioner cited, and that it was convincingly debunked by Dr.
Shinnar’s report and testimony. See K.L. v. Sec’y of Health & Human Servs., 2017 WL
1713110, at *16. The Special Master found Dr. Shinnar’s explanation more credible
because Dr. Shinnar supported his opinion with articles that were “more scientifically
reliable (both given the larger population groups studied, as well as the fact that they
involved observed cases rather than simply reported reactions) and more persuasively
demonstrated no link between a number of neurological events, including epilepsy, and
receipt of the HPV vaccine.” Id. at *15.

        In support of her argument, petitioner cites language from the United States Court
of Federal Claims decision in Contreras v. Secretary of Health and Human Services that
“[p]lausibility . . . in many cases may be enough to satisfy Althen prong one” (emphasis
in original), suggesting that petitioner had a lowered burden of proof with respect to this
prong. Contreras v. Sec’y of Health & Human Servs., 121 Fed. Cl. 230, 245 (2015). The
United States Court of Federal Claims’ Contreras decision petitioner cited, however, was
ultimately vacated and remanded by the United States Court of Appeals for the Federal
Circuit on January 3, 2017, three months before petitioner’s counsel filed the Motion for
Review on petitioner’s behalf. See Contreras v. Sec’y of Health & Human Servs., 844
F.3d 1363 (Fed. Cir. 2017). Petitioner’s counsel fails to note the Federal Circuit’s decision
to vacate and remand the case in the briefs he filed. Furthermore, petitioner’s
understanding of the Contreras decision in the Court of Federal Claims is also incomplete,
because the Court of Federal Claims’ Contreras decision separated a petitioner’s burden
with respect to Althen prong one from a petitioner’s overall burden of proof, noting that
even if plausibility may be sufficient for Althen prong one, this does not alter petitioner’s
overall burden to establish causation-in-fact by more than plausibility alone, stating, “while
plausibility is not enough to show that a particular vaccine caused a particular injury, this
is a separate question from the inquiry required by Althen prong one.” 121 Fed. Cl. at 245
(citing Veryzer v. Sec’y of Health & Human Servs., 100 Fed. Cl. 344, 352 (2011)). In the
present case, because the Special Master determined that petitioner had not produced
sufficient evidence to meet her burden of proof to show a plausible theory of causation
demonstrating that the vaccine caused her injury, and the Special Master supported this
determination with a reasonable and thorough analysis of the evidence in his decision,
the Special Master did not act arbitrarily or capriciously with respect to his conclusions on
the Althen prong one.

        In addition, petitioner argues in her Motion for Review that the Special Master erred
when he found petitioner had failed to satisfy her burden to prove Althen prong two by a
preponderance of the evidence. Specifically, petitioner alleges that Dr. Engstrand’s
explanation of the biological events in K.L.’s illness was sufficient to show a logical
sequence of causation, that her medical records support this explanation, and that
respondent’s alternative theory of causation should be excluded. Under Althen prong two,
a petitioner must show a logical sequence of cause and effect between the vaccine and
petitioner’s injuries, usually supported by evidence from petitioner’s medical records. See

                                             44
Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1278. In the present case, the
Special Master found that petitioner did not sufficiently show that Gardasil caused her
initial seizures, as alleged, because K.L.’s medical records showed no signs that K.L. had
an autoimmune response contemporaneous with her initial seizure after the vaccination
or an upregulation of cytokines, upon which Dr. Engstrand’s causation theory relied. See
K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at *16. The Special Master
also found that the evidence presented by the treating physicians and the government’s
expert provided a more persuasive alternative explanation for K.L.’s illness. Id. In
particular, the Special Master found that Dr. Shinnar had “effectively distinguished K.L.’s
medical presentation with that of a patient with autoimmune epilepsy, who would likely
have displayed abnormal EEG results demonstrating the presence of a neurologic injury,
while at the same time being resistant to treatment.” Id. Similarly, the Special Master
found treating physician Dr. Poduri’s diagnosis of idiopathic epilepsy to be persuasive
because Dr. Poduri was K.L.’s continuing, treating physician, she reviewed numerous
medical tests performed on K.L., and she had expertise in epilepsy. The Special Master
stated in his opinion: “[i]n addition, particularly trustworthy treaters with significant
epilepsy expertise, like Dr. Poduri, were aware of the vaccine’s administration [to K.L.]
but concluded, based on their review of the developing medical record, that more likely
than not K.L.’s epilepsy was idiopathic.” Id. (citations omitted). Provided the Special
Master does so in a reasonable manner and “consider[s] the relevant evidence of record,
draw[ing] plausible inferences and articulat[ing] a rational basis for the decision,” it is
within a Special Master’s discretion to weigh the reliability and credibility of the evidence
a petitioner provides to support his or her theory of causation. Broekelshen v. Sec’y of
Health & Human Servs., 618 F.3d at 1348 (quoting Hines v. Sec’y of Health & Human
Servs., 940 F.2d at 1528). Special Master Corcoran acted reasonably and did not err
when he found the evidence from Drs. Shinnar and Poduri explaining K.L.’s medical
records “more persuasive than Dr. Engstrand’s statements to the contrary.” K.L. v. Sec’y
of Health & Human Servs., 2017 WL 1713110, at *16; see also Burns v. Sec’y of Health
& Human Servs., 3 F.3d at 417 (finding no error when the Special Master found
contemporaneous medical records more persuasive than later oral testimony, because
“such a determination of credibility is uniquely within the purview of the special master”).

        Moreover, the government is permitted to present an alternative theory of
causation to explain the petitioner’s injury, which the Special Master may then consider
in making his or her determination of whether the petitioner has met her burden of proof
demonstrating that the vaccine caused petitioner’s injury. See de Bazan v. Sec’y of Health
& Human Servs., 539 F.3d at 1353 (“The government, like any defendant, is permitted to
offer evidence to demonstrate the inadequacy of the petitioner's evidence on a requisite
element of the petitioner's case[-]in-chief.”); see also Rus v. Sec’y of Health & Human
Servs., 129 Fed. Cl. 672, 680 (2016) (“[R]egardless of whether the burden of proof ever
shifts to the respondent, the special master may consider the evidence presented by the
respondent in determining whether the petitioner has established a prima facie case.”
(citations omitted)). Therefore, it was proper for Special Master Corcoran to consider both
Dr. Engstrand’s causation theory and Dr. Shinnar’s alternative causation theory in the
context of K.L.’s medical records. The United States Court of Appeals for the Federal
Circuit has interpreted 42 U.S.C § 300a-13(2)(b) to mean that a Special Master is
expected to consider the record as a whole in making his or her decision regarding
                                             45
entitlement to compensation, which includes all relevant evidence cited by both parties
throughout the proceedings. See Moriarty v. Sec’y of Health & Human Servs., 844 F.3d
at 1327-28 (“Thus, this statutory language indicates that a special master, reviewing the
entire record of the case before him, must consider all relevant medical and scientific
evidence contained in the record, which includes any relevant medical records or reports.
It also instructs that the special master ‘shall’ consider the entire record, which includes
this relevant evidence, when assigning the weight given to particular evidence.”
(emphasis in original)); see also Stone v. Sec’y of Health & Human Servs., 676 F.3d 1373,
1379 (Fed. Cir. 2012) (“Evidence of other possible sources of injury can be relevant not
only to the ‘factors unrelated’ defense, but also to whether a prima facie showing has
been made that the vaccine was a substantial factor in causing the injury in question.”).

        Petitioner also argues that K.L.’s diagnosis of idiopathic epilepsy by Drs. Shinnar
and Poduri should be discounted because evidence of idiopathic illnesses cannot be used
to deny her recovery. In support of this argument, petitioner cites 42 U.S.C. § 300aa-
13(a)(2)(A) and Wagner v. Secretary of Health and Human Services, 37 Fed. Cl. 134
(1997). Petitioner’s argument misconstrues 42 U.S.C. § 300aa-13(a)(2)(A) and Wagner.
The section of the statute petitioner relies on is only applied when the burden of proof is
on the government to show that a petitioner’s injuries were caused by a factor “unrelated
to the administration of the vaccine,” 42 U.S.C. § 300aa-13(2) either after causation is
presumed because the injury is on-Table or after petitioner has proven causation-in-fact.
See Althen v. Sec’y of Health & Human Servs., 418 F.3d at 1281; see also Rus v. Sec’y
of Health & Human Servs., 129 Fed. Cl. at 680 (“[I]f a petitioner establishes a prima facie
case, the burden shifts to the respondent to show, by a preponderance of the evidence,
that the injury was caused by a factor unrelated to the vaccine.” (citations omitted));
Kotson v. Sec’y of Health & Human Servs., 974 F.2d 157, 158 (Fed. Cir. 1992) (finding
that because the petitioner had an on-Table injury, causation was presumed, so per the
statute an idiopathic illness could not defeat recovery); Doe ex rel. Estate of Doe v. Sec’y
of Health & Human Servs., 83 Fed. Cl. 157, 169 (2008) (finding that the Special Master
misallocated the burden of proof by failing to shift burden to government after petitioner
proved a prima facie case per the statute). In K.L.’s case, 42 U.S.C. § 300aa-13(a)(2)(A)
does not apply because the petitioner’s alleged injury is an off-Table injury and she has
failed to prove causation-in-fact. Therefore, the burden of proof has not shifted to the
government to show that petitioner’s injuries were caused by a factor unrelated to the
vaccine.

       The Wagner case also is not applicable to petitioner’s claim because in Wagner,
the Special Master determined that the petitioner had proven that her injuries were
caused-in-fact by the vaccine by a preponderance of the evidence, and, therefore, that
the burden had shifted to the government to prove that “factors unrelated to the
administration of the vaccine” caused her injury. Wagner v. Sec’y of Health & Human
Servs., 37 Fed. Cl. at 139. The court in Wagner held that an unknown cause could not be
used to deny compensation after a determination that petitioner had proven causation-in-
fact by a preponderance of the evidence. See id. at 138-39. In K.L.’s case, the Special
Master determined that the petitioner has not met her burden of proof, and, thus, the
burden of showing an alternative cause by “factors unrelated to the administration of the
vaccine” by a preponderance of the evidence did not shift to the government. 42 U.S.C.

                                            46
§ 300aa-13(2). Therefore, the Special Master did not act arbitrarily or capriciously with
respect to Althen prong two because he appropriately considered the relevant evidence
in the record regarding the causation of petitioner’s alleged injury, including Dr. Shinnar’s
opinion that K.L.’s epilepsy was idiopathic and Dr. Poduri’s diagnosis reflecting the same.
This court should not re-weigh the evidence the Special Master reasonably reviewed and
evaluated. See Moberly ex rel. Moberly v. Sec’y of Health & Human Servs., 592 F.3d at
1326.

        Petitioner also alleges that she “clearly proved Prong 3” of the Althen test, arguing
that she produced sufficient evidence to show a proximate temporal relationship between
the vaccine and her injury, listing several of the articles Dr. Engstrand cited in her reports.
Petitioner’s motion additionally asserts that the Special Master made a “grudging
admission that petitioner had a strong showing of proof” of Althen prong three. In support
of this assertion, petitioner cites to the portion of the Special Master’s opinion which reads:
“At the same time, however, I acknowledge that a two-day period between vaccination
and seizure has been deemed medically acceptable in other [Vaccine Injury] Program
cases involving epilepsy.” See K.L. v. Sec’y of Health & Human Servs., 2017 WL
1713110, at *15. Petitioner, therefore, argues that the Special Master indicated Althen
prong three favored the petitioner, quoting the following language from the decision: “Yet
even were I to find that the balance of evidence on this matter barely favored K.L.,
that determination would not alter my ultimate decision about causation.” Id. at *16
(emphasis added by petitioner).

        Under Althen prong three, a petitioner must show a “proximate temporal
relationship” between the vaccine and injury alleged that is “medically acceptable.” Althen
v. Sec’y of Health & Human Servs., 418 F.3d at 1281. To meet this standard, a petitioner
must show by a preponderance of the evidence that “the onset of symptoms occurred
within a timeframe for which, given the medical understanding of the disorder’s etiology,
it is medically acceptable to infer causation,” which also corresponds with petitioner’s
theory of how the vaccine caused her injury. de Bazan v. Sec’y of Health & Human Servs.,
539 F.3d at 1352; see also Pafford v. Sec’y of Health & Human Servs., 451 F.3d at 1358-
59 (finding that a temporal relationship is a required element of petitioner’s claim under
Althen). A petitioner, however, cannot rely on a temporal association between her vaccine
and alleged injury alone to show causation. See Moberly ex rel. Moberly v. Sec’y of Health
& Human Servs., 592 F.3d at 1323 (“[A] proximate temporal association alone does not
suffice to show a causal link between the vaccination and the injury.”) (quoting Grant v.
Sec’y of Health & Human Servs., 956 F.3d at 1148); de Bazan v. Sec’y of Health & Human
Servs., 539 F.3d at 1352 (“[T]he proximate temporal relationship prong requires
preponderant proof that the onset of symptoms occurred within a timeframe for which,
given the medical understanding of the disorder's etiology, it is medically acceptable to
infer causation-in-fact.”); Pafford v. Sec’y of Health & Human Servs., 451 F.3d at 1358
(finding that the Special Master properly required evidence of a temporal relationship
between the vaccine and petitioner’s injury); see also K.T. v. Sec’y of Health & Human
Servs., 132 Fed. Cl. at 186. Moreover, because a proximate temporal association alone
cannot prove causation, consistency in the timing of the onset of symptoms with a theory
that is itself scientifically unreliable will not cure the theory’s unreliability or overcome
petitioner’s failure to satisfy her burden of proof. See, e.g., Moberly ex rel. Moberly v.

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Sec’y of Health & Human Servs., 592 F.3d at 1323; see also K.T. v. Sec’y of Health &
Human Servs., 132 Fed. Cl. at 186; Shapiro v. Sec’y of Health & Human Servs., 101 Fed.
Cl. 532, 542 (2011).

        Regarding petitioner’s argument that the Special Master “made a grudging
admission that petitioner made a strong showing of proof” regarding Althen prong three,
petitioner misses the critical word “were” in the sentence cited from the Special Master’s
decision. The sentence33 indicates that the Special Master was addressing the issue
hypothetically, essentially thinking through the issues, not that he was ruling in petitioner’s
favor on prong three of Althen because of the absence of a provable theory of causation.
Petitioner’s counsel overstates the Special Master’s findings regarding Althen prong
three. The Special Master did not make a “grudging admission that petitioner made a
strong showing of proof” on prong three, as petitioner alleges, but rather found that
resolution of this prong was “less easily accomplished” because “Dr. Engstrand’s theory
proposed that cytokine upregulation would occur in the two-day timeframe at issue
herein.” K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at *16. Special
Master Corcoran ultimately determined that petitioner had not proven prong three of
Althen, and finding that, “[a]t bottom, Petitioner’s theory is itself too unreliable to put stock
in the fact that timing as evidenced by the facts herein is consistent with that theory.” Id.
at *17. As the factfinder, the Special Master had discretion to weigh the evidence
presented, and it was not an abuse of that discretion for him to determine that petitioner
also had not clearly met prong three because the medical literature Dr. Engstrand offered
to show that the timeframe was “medically appropriate” was insufficient in K.L.’s case. Id.
at *16. The Special Master provided the requisite “rational basis” for his determination.
See, e.g., Hibbard v. Sec’y of Health & Human Servs., 698 F.3d at 1363. The Special
Master pointed out in his opinion that the Crawford study Dr. Engstrand offered for the
record related to patients with previously diagnosed epilepsy, and the Spiczak study Dr.
Engstrand offered related to vaccines other than HPV. K.L. v. Sec’y of Health & Human
Servs., 2017 WL 1713110, at *16. Thus, this court finds that the Special Master was not
arbitrary or capricious in finding that the petitioner failed to meet her burden to prove
Althen prong three.

                                        CONCLUSION

       Upon review of the record before this court, including testimony taken at the
hearing before Special Master Corcoran, the medical records, exhibits, conflicting expert
reports, and Special Master Corcoran’s decision, this court finds that Special Master
Corcoran employed the proper standards of proof and that his final decision, which
concluded that petitioner failed to prove, by a preponderance of the evidence, a medical
theory of causation between the Gardasil vaccination and petitioner’s medical condition

33“Yet even were I to find that the balance of evidence on this matter barely favored K.L.,
that determination would not alter my ultimate decision about causation, because
Petitioner's causation theory itself is too deficient, and unsupported by the actual medical
history.” K.L. v. Sec’y of Health & Human Servs., 2017 WL 1713110, at *17 (emphasis
added).

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was not arbitrary or capricious. The Special Master’s ruling on entitlement denying
compensation to petitioner is AFFIRMED.

      IT IS SO ORDERED.

                                                s/Marian Blank Horn
                                                MARIAN BLANK HORN
                                                         Judge

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