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


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  •                In the United States Court of Federal Claims
    OFFICE OF SPECIAL MASTERS
    Filed: February 19, 2020
    * * * * * * * * * * * * * *                   *
    JAMES F. DUNN,                                *       PUBLISHED
    *
    Petitioner,                    *       No. 16-1506V
    *
    v.                                            *       Special Master Dorsey
    *
    SECRETARY OF HEALTH                           *       Tetanus-Diphtheria-Acellular Pertussis
    AND HUMAN SERVICES,                           *       Vaccine (“Tdap”); Varicella Zoster Virus
    *       (“VZV”) Infection; Meningoencephalitis;
    Respondent.                    *       Reactivation; Alternative Factor Unrelated
    *       to Vaccine
    * * * * * * * * * * * * * *                   *
    Jeffrey A. Golvash, Brennan, Robins & Daley, P.C., Pittsburgh, PA, for petitioner.
    Darryl R. Wishard, United States Department of Justice, Washington, DC, for respondent.
    DECISION1
    I.     INTRODUCTION
    On November 14, 2016, James F. Dunn (“petitioner”) filed a petition under the National
    Vaccine Injury Compensation Program (“Vaccine Act” or “the Program”),2 42 U.S.C. § 300aa-
    10 et seq. (2012), alleging that as a result of receiving a Tetanus-diphtheria-acellular pertussis
    1
    Because this decision contains a reasoned explanation for the undersigned’s action in this case,
    the undersigned intends to post this decision on the website of the United States Court of Federal
    Claims, in accordance with the E- Government Act of 2002, 
    44 U.S.C. § 3501
     note (2012)
    (Federal Management and Promotion of Electronic Government Services). This means the
    Decision will be available to anyone with access to the Internet. As provided by Vaccine
    Rule 18(b), each party has 14 days within which to request redaction “of any information
    furnished by that party: (1) that is a trade secret or commercial or financial in substance and is
    privileged or confidential; or (2) that includes medical files or similar files, the disclosure of
    which would constitute a clearly unwarranted invasion of privacy.” Vaccine Rule 18(b).
    2
    The National Vaccine Injury Compensation Program is set forth in Part 2 of the National
    Childhood Vaccine Injury Act of 1986, Pub. L. No. 99-660, 
    100 Stat. 3755
    , codified as amended,
    42 U.S.C. §§ 300aa-10 to -34 (2012). All citations in this decision to individual sections of the
    Vaccine Act are to 42 U.S.C. § 300aa.
    1
    (“Tdap”) vaccine on December 2, 2014,3 he developed meningoencephalitis. Petition at
    Preamble; Joint Prehearing Submission (“Joint Sub.”), filed May 23, 2019, at 1 (ECF No. 59).
    Petitioner asserts that the Tdap vaccination he received in December 2014, caused an
    “immune-mediated inflammatory response, such as occurs with normal antibody production
    post-Tdap vaccination” resulting in meningoencephalitis. Petitioner’s Prehearing Submission at
    6 (ECF No. 53). Respondent argues against awarding compensation, stating that petitioner failed
    to provide preponderant evidence that his illness was caused by the Tdap vaccine. Respondent’s
    Report at 9. Respondent also contends that petitioner’s meningoencephalitis was caused by a
    varicella zoster virus (“VZV”) infection, an alternative factor, unrelated to the Tdap vaccine.
    Respondent’s Pre-Hearing Brief at 1 (ECF No. 58).
    Petitioner suffered a very serious and significant illness which required hospitalization in
    an intensive care unit. He suffered respiratory failure requiring intubation and ventilation, and
    other sequela, which had a profound impact on his life, for which the undersigned extends her
    sympathy. However, after carefully analyzing and weighing all of the evidence and testimony
    presented in this case in accordance with the applicable legal standards, the undersigned finds
    that petitioner is not entitled to compensation.
    Even assuming that petitioner provided preponderant evidence of causation, the
    undersigned finds that respondent proved by preponderant evidence that petitioner’s
    meningoencephalitis was caused by VZV infection reactivation, an alternative factor unrelated to
    his Tdap vaccination. Therefore, petitioner is not entitled to compensation, and his case must be
    dismissed.
    II.    PROCEDURAL HISTORY
    Petitioner, James F. Dunn, filed for compensation under the National Vaccine Injury
    Compensation Program on November 14, 2016. Petitioner alleged that he developed viral
    encephalopathy/aseptic meningitis, which was caused-in-fact by the Tdap vaccination he
    received on December 2, 2014. Petition at Preamble. Petitioner alleged that he “suffered from
    the residual effect and/or complication from his viral encephalopathy/aseptic meningitis for more
    than six (6) months.” Id. at ¶ 14. Petitioner filed medical records on January 9, 2017.
    Petitioner’s Exhibits (“Pet. Exs.”) 2(a)-5(b). Respondent filed his Rule 4(c) Report on March 8,
    2017, recommending against compensation. Respondent’s Report at 9 (ECF No. 12).
    Petitioner filed additional medical records on May 5, 2017. Pet. Exs. 6-8. On August 28,
    2017, petitioner filed the expert report of Dr. George Small, a neurologist, and respondent filed
    the expert report by Dr. Subramanian Sriram, a neurologist, on November 9, 2017. Pet. Ex. 9;
    Respondent’s Exhibit (“Resp. Ex.”) A. Petitioner filed a responsive expert report from Dr. Small
    on January 9, 2018. Pet. Ex. 10.
    3
    The parties later stipulated that petitioner received the Tdap vaccine on either December 2, or
    December 4, 2014. Joint Sub., filed May 23, 2019, at 1 (ECF No. 59). For purposes of this
    decision, December 2, 2014 will be referred to as the date of vaccination.
    2
    On February 5, 2018, respondent filed a second expert report from Dr. Sriram, including
    responses to questions the special master posed during the January 25, 2018 Status Conference
    and responses to Dr. Small. Resp. Exs. E, M. During this period, the parties discussed
    settlement of this matter but were unable to resolve the case informally. Respondent’s Status
    Report, filed Mar. 7, 2018 (ECF No. 40). Petitioner then filed responses to questions the special
    master posed and a responsive expert report from Dr. Small on May 18, 2018. Pet. Exs. 13, 19.
    Both parties filed medical literature referenced by their respective experts.
    Petitioner filed additional medical records on October 15, 2018. Pet. Ex. 21. On October
    19, 2018, respondent filed a supplemental expert report from Dr. Sriram. Resp. Ex. N.
    Petitioner filed a third expert report from Dr. Small on April 25, 2019, and respondent filed
    another expert report from Dr. Sriram in response on May 23, 2019. Pet. Ex. 22; Resp. Ex. P.
    The parties filed a joint stipulation of facts on May 23, 2019, in which they agreed that
    the petitioner received the Tdap vaccination in December 2014 (either on December 2, 2014 or
    December 4, 2014) in the United States, and that he was diagnosed with meningoencephalitis in
    December 2014. Joint Sub., filed May 23, 2019, at 1 (ECF No. 59). The parties disagreed on the
    significance of the VZV test performed on the petitioner during his admission at Allegheny
    General Hospital (“AGH”) in December 2014. Id. at 2.
    An entitlement hearing was held on June 26, 2019 in Pittsburgh, Pennsylvania. Dr. Small
    testified on behalf of the petitioner. Dr. Sriram testified on behalf of respondent. Post-hearing,
    petitioner and respondent both continued to file additional exhibits, including medical literature
    and expert reports until the record was closed on November 26, 2019. Petitioner filed a fourth
    expert report from Dr. Small on November 15, 2019. Pet. Ex. 38. Respondent filed a final
    expert report from Dr. Sriram on November 26, 2019. Resp. Ex. S.
    The matter is now ripe for adjudication.
    III.   ISSUES TO BE DECIDED
    The parties dispute causation.4 Petitioner asserts that his Tdap vaccination caused him to
    suffer meningoencephalitis and maintains that he has proven by preponderant evidence the
    standards articulated in Althen. See Althen v. Sec’y of Health & Human Servs., 
    418 F.3d 1274
    ,
    1280 (Fed. Cir. 2005), Joint Sub., filed May 23, 2019, at 2 (ECF No. 59). Respondent disagrees.
    Moreover, respondent contends that even if petitioner has met his burden under Althen, there
    was an alternate cause for petitioner’s illness, unrelated to his vaccination. Respondent
    “contends that petitioner’s VZV infection was the likely cause of his meningoencephalitis.” 
    Id.
    4
    In addition, the respondent disagrees with the tentative findings set forth in an Order filed April
    6, 2017, as to whether petitioner’s evidence meets the severity requirements under the Act. See
    42 U.S.C. §§ 300aa-11(c)(1)(D)(i), (iii); Joint Sub., filed May 23, 2019 at 2 (ECF No. 59). This
    decision makes that tentative finding not relevant. The parties also dispute the significance of
    petitioner’s testing regarding VZV infection. That issue will be discussed in the context of the
    experts’ opinions and causation analysis.
    3
    For purposes of this decision, the undersigned assumes that petitioner has proven his case,
    and that the burden then shifted to respondent to show that a factor unrelated to the vaccination
    caused petitioner’s meningoencephalitis. Therefore, the causation analysis relates only to
    respondent’s theory of causation and does not include an analysis of petitioner’s causation claim.
    IV.      FACTUAL SUMMARY
    A. Summary of Facts
    In his Prehearing Memorandum, petitioner sets forth a summary of facts which the
    undersigned finds generally accurate, with some additions and explanations. Petitioner’s
    Prehearing Memorandum, filed Apr. 25, 2019, at 1-4 (ECF No. 53). The summary below is
    largely derived from petitioner’s summary.5
    At the time petitioner received the vaccination at issue in this case, he was forty-four
    years old, active, and working. On November 14, 2013, petitioner weighed 348 pounds, and was
    diagnosed as morbidly obese. His blood pressure was elevated at 137/97. Pet. Ex. 2(a) at 1, 2,
    175. Petitioner’s past medical history was significant for ocular stroke,6 obstructive sleep apnea,
    post-traumatic stress disorder, and hyperlipidemia. Pet. Ex. 4(a) at 118, 123, 126.
    On December 2, 2014, petitioner received a Tdap vaccine at the Veteran’s Administration
    Hospital (“VA”). Pet. Ex. 3. On or about December 12, 2014, he began to experience
    headaches. Petition at ¶ 4. Approximately on December 18, 2014, petitioner began to have flu-
    like symptoms including fever, chills, headache, and mild nausea. Id.; Pet. Ex. 5(b) at 298. On
    December 19, 2014, petitioner awoke feeling warm, fatigued, and generally not himself. Petition
    at ¶ 5; Pet. Ex. 4(a) at 8, 118, 123, 126, 129. Petitioner went to work but left work early to return
    home. Petition at ¶ 5; Pet. Ex. 4(a) at 8, 118, 123, 126, 129. When petitioner’s wife arrived
    home, petitioner was unable to respond to questions or commands. Petition at ¶ 5; Pet. Ex. 4(a)
    at 8, 118, 123, 126, 129. She dialed 911 for emergency medical assistance and petitioner was
    taken by ambulance to AGH for evaluation and treatment. Petition at ¶ 5; Pet. Ex. 4(a) at 8, 118,
    123, 126, 129.
    When petitioner arrived at the emergency room, he was nonverbal and nonresponsive,
    could open his eyes to painful stimuli, but was otherwise encephalopathic. Pet. Ex. 4(a) at 8,
    118, 121, 123. CT and MRI of head and chest X-ray were unremarkable. Due to his altered
    mental status (“AMS”), a lumbar puncture (“LP”) was performed. Pet. Ex. 4(a) at 8, 118-19,
    121, 123, 126-27. Cerebral spinal fluid (“CSF”) analysis revealed elevated white blood cells of
    16 and elevated protein of 63 and glucose of 83. Pet. Ex. 4(d) at 741. Bacterial antigens and
    Gram stain were negative. Polymerase chain reaction (“PCR”) for herpes simplex virus (“HSV”)
    5
    Petitioner’s summary for events occurring after November 2015 is not included here.
    6
    A brain MRI done October 23, 2013 showed small old lacunar infarct in the right superior
    frontal periventricular white matter. Pet. Ex. 2(a) at 21. On October 25, 2013, petitioner was
    diagnosed with central retinal artery occlusion and acute vision loss of his left eye. Id. at 48.
    4
    and VZV were also negative. Id. at 741-42. Influenza type A, B, and A-H1N1 were all negative.
    Id. Cryptococcal antigen was negative. Pet. Ex. 4(a) at 8, 118-19, 126-27; 129-31; Pet. Ex. 4(d)
    at 741-42.7 Blood cultures were also negative. Petitioner was started on empiric antiviral and
    antibiotic therapy with acyclovir, ceftriaxone, and vancomycin. Pet. Ex. 4(a) at 8, 118, 126, 129.
    He was transferred to ICU for continued evaluation and treatment. Id. at 126. Impression was
    altered mental status likely secondary to viral encephalitis/aseptic meningitis. Id. at 127.
    Petitioner was seen by an infectious disease specialist on December 20, 2014. He was
    observed to be nonresponsive and otherwise encephalopathic. Pet. Ex. 4(a) at 119. He had no
    evidence of skin rash. Id. Assessment was encephalopathy secondary to toxic ingestion versus
    nicotine toxicity versus viral encephalitis, possible meningoencephalitis, abnormal cerebrospinal
    fluid, and hypoxia. Id. at 21, 119. The infectious disease specialist suspected abnormal CSF
    findings were reactive in nature as petitioner did not have any evidence of infection. Id. at 119.
    Petitioner was also seen by a neurologist on December 20, 2014. Id. at 130. Temperature was
    37.8 ºC and the petitioner was noted to be confused, nonverbal, unable to track, exhibiting non-
    purposeful movements but without seizures, and there was no evidence of skin rash. Id. The
    neurologist assessment was altered mental status, likely viral encephalitis considering the CSF.
    Id. at 130-31.
    Petitioner remained in the ICU through December 24, and was nonresponsive, unable to
    follow commands, unable to verbalize, hyper-reflexive, and encephalopathic. Pet. Ex. 4(a) at 25-
    28. Due to acute respiratory failure, he underwent bronchoscopy on December 23, 2014. Id. at
    132. A biopsy of the lung Gram stain, bacterial culture, and viral culture were all negative. Pet.
    Ex. 4(d) at 761. Following his bronchoscopy, petitioner continued to be followed and monitored
    in the ICU. Petitioner remained encephalopathic as he continued to be nonverbal without
    showing any signs of understanding. Pet. Ex. 4(a) at 44, 140. His differential diagnosis was
    encephalitis/aseptic meningitis.8 Id. at 37, 47. On December 23, 2014, a bilateral rash was
    subsequently observed and swabs were sent for testing.9 Id. at 36, 140. He had a PICC line
    inserted on December 24, 2014 for fluid and medications. Id. at 42. Petitioner remained
    nonresponsive and noncommunicative with intermittent body tremors.
    On December 25, 2014, petitioner’s mental status began to improve. He awoke on that
    day and was alert and oriented as to time, place, and person. The antivirals and antibiotics were
    discontinued. Pet. Ex. 4(a) at 140.
    7
    Urine toxicology screen was positive for benzodiazepines and cannabinoids. It was noted that
    petitioner used cannabis daily and that he vaped nicotine. Pet. Ex. 4(a) at 8; Pet. Ex. 4(d) at 739.
    8
    Aseptic meningitis is defined as “any of several mild types of meningitis, most of which are
    caused by viruses.” Dorland’s Illustrated Medical Dictionary 1117 (33rd ed. 2020).
    9
    Additional details about petitioner’s rash and swab testing are set forth below in section ii:
    “Additional Facts Regarding Rash and Diagnostic Testing.”
    5
    Given his continued improved mental state, petitioner was discharged from the hospital
    on December 27, 2014 with instructions to follow up with his primary care physician. Pet. Ex.
    4(a) at 62, 140. At the time of discharge, petitioner’s differential diagnosis was altered mental
    status secondary to encephalitis/aseptic meningitis and acute respiratory failure secondary to
    encephalitis/aseptic meningitis. Id. at 57, 62. On December 26, 2014, the infectious disease
    physician wrote, “encephalopathy resolved—suspect nicotine overdose initially followed by
    withdrawal.” Id. at 60. The discharge summary dated December 27, stated “leukocytosis
    concerning for viral etiology” and PCR for VZV and HSV were negative. Id. at 140. (The
    reference to PCR here applies to CSF.) The discharge note does not reference the PCR swab test
    for petitioner’s rash. See Pet. Ex. 4(d) at 758. At the time of discharge, petitioner had word-
    finding difficulty, general fatigue, and some short-term memory lapses. Petition at ¶ 8.
    i.   Subsequent Care
    On January 13, 2015, petitioner was seen in follow-up by his primary care physician,
    Derek Pae, M.D., at the VA. Dr. Pae noted petitioner’s recent hospitalization for altered mental
    status and presumptive diagnosis of viral encephalitis. Pet. Ex. 5(b) at 303-04. Petitioner
    reported a depressed mood, cognitive/short term memory deficiency, and that he generally felt
    “clouded,” which affected his ability to function. Id. Dr. Pae recommended further consult and
    evaluation by an infectious disease specialist. Id.
    Petitioner was seen by Jae Ho Hong, M.D., an infectious disease specialist at the VA, on
    January 28, 2015. Pet. Ex. 5(b) at 296. During the visit, Dr. Hong noted, “Most likely the cause
    was viral encephalitis. However, on reviewing the chart, he received Tdap vaccine on the
    beginning of December. . . . Post-vaccination ADEM [acute disseminated encephalomyelitis]
    has been associated with several vaccines such as rabies, diptheria?tetanus? . . . . Anyway, he is
    clinically improving and no need for further testing or treatment.” Id. at 297. Subsequently on
    February 4, 2015, Dr. Hong prepared an allergy and immunology adverse event note. In the
    adverse event note, Dr. Hong reported that petitioner had a Tdap vaccine on December 2, 2014
    and that petitioner was hospitalized on December 19, 2014 with altered mental status and aseptic
    meningitis.10 Id. at 296, 357.
    On March 24, 2015, petitioner was again seen by Dr. Pae. Petitioner continued to have
    short-term memory lapses and lethargy. Pet. Ex. 5(b) at 292-93. The short-term memory lapses
    impacted petitioner’s ability to perform everyday living activities. Id. Dr. Pae suspected that
    petitioner’s cognitive defects and short-term memory loss was caused by his hospitalization and
    worsened by depression. Id. Dr. Pae prescribed an antidepressant (sertraline). Id. at 292-93,
    364. On May 12, 2015, petitioner presented to Dr. Pae in follow-up. Petitioner’s cognitive
    defects, memory loss, and depression had improved since taking sertraline. Pet. Ex. 5(a) at 95.
    10
    Adverse Event Note states: “PT was admitted to AGH on 12/19/2014 with AMS. LP shows
    aseptic meningitis result. Had Tdap vaccine on 12/2/14.” Pet. Ex. 5(b) at 357.
    6
    Petitioner next saw Dr. Pae on November 10, 2015. Pet. Ex. 5(a) at 93. Dr. Pae wrote: “I
    am [] concerned because after his hospitalization for encephalitis, no known cause found and per
    ID [infectious disease], most likely 2/2 [secondary to] tetanus vaccine. He is understandably
    reluctant about future vaccines.” Id. at 94.
    On November 25, 2015, petitioner sought emergency care for fever and chills. His prior
    medical history noted his previous hospitalization for encephalitis, which may have been
    secondary to Tdap vaccine. Petitioner was discharged the next day with his symptoms resolved.
    Pet. Ex. 5(a) at 20-21.
    Petitioner was seen in follow-up by Dr. Omran on December 2, 2015. Petitioner’s past
    medical history was significant for “encephalitis in 2014, temporal link to tetanus vaccine” and
    “adverse reaction/allergy to Tdap”. Pet. Ex. 5(b) at 191-92. At that time, petitioner was still
    taking sertraline for his depression. Id.
    On May 6, 2016, petitioner was seen by a rheumatologist at the VA. His prior medical
    history was significant for aseptic encephalitis/meningitis that may be Tdap vaccine related. Pet.
    Ex. 5(b) at 99. Petitioner was still taking sertraline. Id. By July 13, 2016, approximately one
    and half years after his initial hospitalization, initial mental slowing, progress notes reflect that
    petitioner’s cognitive/memory impairment had resolved. Id. at 119.
    ii.   Additional Facts Regarding Rash and Diagnostic Testing
    In addition to the facts set forth above, the following facts are relevant and pertinent.
    On the date of vaccination, petitioner presented to Dr. Pae on December 2, 2014, for a
    routine follow-up visit. On that date, Dr. Pae noted that Mr. Dunn had “a truncal rash which
    does not itch or cause pain.” This problem had been treated in the past with medication. Pet. Ex.
    5(b) at 371. Dr. Pae also documented that petitioner had “another separate lesion on his right
    arm which is different and itchy. He has always had ‘skin problems’ in the past but this is new.”
    Id. Dr. Pae diagnosed Mr. Dunn’s truncal rash as “suspect[ed] tinea corporus” (fungus) and the
    lesion on his right arm as eczema. Id. Mr. Dunn received the Tdap vaccine at this visit. Id. at
    373.
    On December 19, 2014, petitioner was taken to the AGH emergency department with
    decreased mental status and admitted for evaluation and treatment. Lab work testing included
    blood work for VZV IgG, which was positive: VZV IgG: ˃4000.11 Pet. Ex. 4(a) at 189.
    Diagnostic testing was ordered on December 20, 2014, including CSF tests by PCR for a
    number of viruses, including HSV, VZV, enterovirus, West Nile virus, Lyme Disease, syphilis,
    human immunodeficiency virus, and others. Pet. Ex. 4(a) at 189. The results of the PCR tests on
    11
    Petitioner’s result was greater than 4,000 units. A positive result is generally greater than 165
    units. Pet. Ex. 4(d) at 746.
    7
    the petitioner’s cerebrospinal fluid were ultimately reported back as negative, including the test
    for VZV.12 Id.; Pet. Ex. 4(d) at 741-42.
    On December 23, 2014, an infectious disease physician documented the presence of skin
    vesicles on petitioner’s left chest and left upper extremity where the cardiac monitor pad and BP
    cuff had been placed. Pet. Ex. 4(a) at 36. The vesicles looked like “contact dermatitis” as they
    were not in a dermatomal distribution. Id. “However, given possible viral
    meningitis/encephalitis, shingle/herpetic lesions should be ruled out.” Id. “Blister in LUE [left
    upper extremity] and chest—not typical appearance of shingles but [] and fever, droplet
    precautions given that patients next room are immunosuppressed. Skin lesions in VZV
    encephalitis may develop after AMS even during tx [treatment].” Id. 35.
    The physician ordered droplet isolation, and a PCR swab test from the left wrist blister
    for herpes simplex virus and VZV. Pet. Ex. 4(a) at 35. The physician also ordered to continue
    IV acyclovir (antiviral) until the cerebrospinal fluid and blister swab results were returned. Id.
    The PCR of the blister subsequently tested positive for VZV. Pet. Ex. 4(d) at 758.
    Petitioner’s medical records do not state when the results of the positive VZV blister test
    were received or whether his physicians were notified of the results. There is no reference to the
    results in the physicians’ progress notes or petitioner’s discharge summary. The test results
    appear in the laboratory reports section of the petitioner’s medical records. Pet. Ex. 4(d) at 758.
    During the hearing, upon review of the lab reports, it was noted that the swab PCR
    (“miscellaneous fluid”) was performed at LabCorp, an outside laboratory. Pet. Ex. 4(d) at 758;
    Transcript (“Tr.”) 170. After the hearing, petitioner obtained the report from LabCorp, which
    notes that the test was drawn on December 23, 2014 and reported on December 30, 2014. The
    results were positive for VZV; “varicella zoster virus DNA [was] detected.” Pet. Ex. 39 at 2.
    iii.   Petitioner’s Testimony
    Mr. Dunn was born October 24, 1970. He testified that as a child he had chickenpox. Tr.
    30. He received the Tdap vaccine at issue in this case on December 2, 2014. Tr. 8.
    On December 12, 2014, Mr. Dunn started having headaches. Tr. 11. On the evening of
    December 18, 2014, he had nausea, dizziness, fever, and chills. Id. The next day, December 19,
    2014, he felt ill, and left work and drove home at noon. Tr. 12. When he arrived home, he went
    upstairs to lie down. Id. That is his last memory until December 25, 2014, when he came out of
    a coma. Tr. 16.
    12
    Varicella virus testing described in this decision includes serological antibody testing of
    peripheral blood, and viral DNA PCR testing of cerebrospinal fluid and of a fluid filled vesicle.
    Petitioner’s VZV IgG test was positive, indicating that he tested positive for antibodies to the
    varicella virus. See Mosby’s Manual of Diagnostic and Laboratory Tests 712-75 (Kathleen D.
    Pagana & Timothy J. Pagana eds., 6th ed. 2018). Varicella virus DNA proteins can be detected
    by PCR. Id. at 713. Here, petitioner had PCR analysis of his CSF on December 20, and then of
    fluid in a vesicle on December 23. The PCR on the CSF was negative. The PCR of the vesicle
    fluid was positive.
    8
    Based on information shared with him by his wife, petitioner testified that on December
    19, 2014, when Ms. Dunn arrived home, she found her husband ill, and she called 911. Tr. 12.
    Mr. Dunn was taken by ambulance to AGH. Id. Mr. Dunn explained that he had not told his
    wife that he received the Tdap vaccine, and she did not inform petitioner’s health care providers
    of his history of Tdap vaccination when petitioner was taken to the hospital. Tr. 14.
    Petitioner was questioned regarding Dr. Pae’s medical records, specifically, the entry
    dated December 2, 2014, which documented that petitioner had a truncal rash. See Pet. Ex. 5(b)
    at 371. Petitioner explained that he told Dr. Pae that in the past he had taken medication for the
    rash and it cleared up. Tr. 24. Dr. Pae’s records also note that petitioner had a separate lesion on
    the right arm which was “different and itchy.” Id.; Pet. Ex. 5(b) at 371. Dr. Pae stated that Mr.
    Dunn had skin problems in the past, but this was a new problem. Pet. Ex. 5(b) at 371.
    Petitioner testified that he had a history of sensitive skin, and a nickel allergy, along with
    a long history of skin allergies. Tr. 29. He testified, however, that he had never sought treatment
    for a painful rash. Tr. 30. Petitioner also testified that he did not have a painful skin rash
    between December 2, 2014 and December 19, 2014. Tr. 10.
    Significantly, Mr. Dunn testified that while he was a patient at AGH, no one ever told
    him that he tested positive for shingles (VZV). Tr. 31. Further, when he was discharged from
    the hospital, he was not informed of his positive shingles test or VZV diagnosis. Tr. 21.
    Petitioner did not become aware that he had a positive PCR test for shingles until his lawyer told
    him during the pendency of this claim. Id.
    iv.    Contemporaneous Treating Physician Assessments
    During petitioner’s admission to AGH in December 2014, he was initially seen by an
    emergency room physician and then followed by several specialists, including neurology,
    infectious disease, and while in the ICU, critical care physicians. The following is a chart with
    the daily assessments charted by these physicians.
    Date                              Clinical impression                          Pet. Ex. 4(a) at
    12/19/14           Initial progress note – altered mental status (AMS)                  9
    encephalitis/meningitis/intoxication . . . intoxication unlikely
    12/20                       Likely viral meningoencephalitis                           10
    12/20                             Most likely infectious                               16
    12/20                  ? etiology appears to have viral infection.                     22
    LP WBC 16
    12/21                           Could be viral meningitis                              12
    12/21           Etiology unclear ? nicotine toxicity ? viral encephalitis              14
    12/21         Possible meningoencephalopathy but also consistent with                  15
    toxic exposure
    12/22                        Concern for infectious etiology                           25
    12/22                         Infectious vs. encephalopathy                            25
    12/22                            Likely viral encephalitis                             32
    9
    12/23       ID noted some vesicles left chest, LUE… shingles/herpetic               36
    lesions should be ruled out
    12/23        Aseptic meningitis CT [continue] Acyclovir follow PCR                  37
    12/24           AMS – unclear etiology most likely viral etiology                   50
    12/25                 AMS – unclear etiology. Likely viral                          52
    12/25              AMS 2/2 [secondary to] HSV encephalitis ?                        54
    CSF HSV PCR negative
    12/26                 Encephalitis 2/2 [secondary to] viral ?                       57
    12/26                       Encephalopathy resolved.                                59
    Abnormal CSF w/ viral pleocytosis
    12/26       Encephalopathy resolved, suspect nicotine overdose initially            60
    followed by withdrawal
    12/27                 AMS secondary to aseptic meningitis                           62
    B. Expert Qualifications and Opinions
    i.   Expert Qualifications
    a. Petitioner’s Expert, Dr. George Allen Small
    Dr. George Allen Small is a board-certified neurologist and is the Director of Allegheny
    General Hospital’s EMG Laboratory and Neuromuscular Service. Pet. Ex. 9 at 5-6. Dr. Small is
    also an Associate Professor of Neurology at Drexel University School of Medicine and at the
    Temple University School of Medicine. Id. at 5; Tr. 37. Dr. Small received his M.D. from
    Jefferson Medical College and completed his residency at the Neurological Institute of New
    York. Pet. Ex. 9 at 5. He also serves as the Program Director for the Clinical Neurophysiology
    Fellowship. Id. Dr. Small has published numerous articles. Id. at 9-11.
    Dr. Small has treated hundreds of patients with encephalitis, and of those, most did not
    have a recognized or known etiology for their illness. He testified that the most common viral
    cause is the herpes virus type one (HSV). Tr. 102. Dr. Small has also seen cases of
    postvaccination encephalitis, but “not very many.” Id.
    Dr. Small has privileges to practice at AGH, the hospital where petitioner was admitted
    and received care in December 2014, but he does not recall caring for or treating petitioner. Tr.
    111
    b. Respondent’s Expert, Dr. Subramaniam Sriram
    Dr. Subramaniam Sriram is a board-certified neurologist with a focus in
    neuroimmunology. See Resp. Ex. Q at 2. He obtained a Bachelor of Medicine and a Bachelor of
    Surgery from the University of Madras in Madras, India. Id. at 1. He then served as an intern
    and resident at Wayne State University and completed a residency in neurology at Stanford
    University, where he also served as chief resident and eventually completed a post-doctoral
    fellowship in neuroimmunology. Id. Currently, Dr. Sriram serves as the William Weaver
    Professor of Experimental Neurology at Vanderbilt University Medical Center. Id. at 2; Tr. 140.
    10
    He also holds a joint appointment as Professor of Pathology, Microbiology, and Immunology.
    Resp. Ex. Q at 2. Dr. Sriram’s clinical practice includes seeing patients two days a week. Tr.
    140.
    Like Dr. Small, Dr. Sriram has treated patients with meningoencephalitis, including cases
    caused by VZV. He has also authored a paper about a patient with VZV encephalitis. Resp. Ex.
    Q at 19; Tr. 142. That patient had CSF findings consistent with VZV, but had abnormal eye
    movements (ocular findings) and did not present with encephalitis or meningitis. Tr. 142. Of
    note, two to three weeks later, the patient developed a shingles lesion. Id.
    ii.   Expert Opinions
    a. Petitioner’s Expert, Dr. Small13
    Dr. Small opined that petitioner’s meningoencephalitis was due to a reaction to the Tdap
    vaccine that he received on December 2, 2014. Tr. 73-74, 106. Dr. Small defined
    meningoencephalitis as altered mental status for greater than twenty-four hours with “objective
    evidence of inflammation in the brain” and spinal fluid. Tr. 60. He further explained that
    meningoencephalitis encompasses aseptic meningitis (inflammation of meninges as evidenced
    by cerebrospinal fluid analysis) and encephalitis (inflammation of the brain as evidence by
    dysfunction of the brain). Tr. 69. He further explained that aseptic meningitis also suggests that
    no viral or bacterial organism is found in the spinal fluid. Tr. 70-71.
    Petitioner’s cerebrospinal fluid showed elevated white blood cells and protein. Pet. Ex.
    4(d) at 741. Cultures and PCR testing of the CSF did not reveal a specific virus or bacteria. Tr.
    50, 55-56. Dr. Small explained that the CSF was “reactive,” meaning that the tests suggested an
    inflammatory and immunological reaction to some agent. Tr. 52. However, according to Dr.
    Small, the CSF results ruled out the possibility of active viral or bacterial meningoencephalitis.
    Tr. 55-57.
    With regard to Althen Prong One, Dr. Small posits that the Tdap vaccine causes the
    following immunological reaction: The bacterial antigen in the vaccine initiates an immune
    response (T cells interacting with B cells) that results in the production of protective antibodies
    against the bacterial antigen. Tr. 76; Pet. Ex. 9 at 2. The immune response also results in the
    production of proinflammatory cytokines, including interleukin 6 (Il-6), and tumor necrosis
    factor-α (TNF-α). Tr. 76. According to Dr. Small, these cytokines break down the blood brain
    barrier, which normally protects the brain from noxious material, and allows for inflammation of
    the central nervous system and brain to occur. Tr. at 77-78. The inflammation causes abnormal
    function, including altered mental status. Id. Dr. Small testified that the inflammation causes
    damage to the brain, and the waste products of that damage elevate the protein level in the
    cerebrospinal fluid. Tr. at 80. The “immunization-promoted inflammatory response becomes
    exuberant and spills over into the central nervous system.” Pet. Ex. 9 at 3.
    13
    Petitioner filed six expert reports authored by Dr Small. Pet. Exs. 9, 10, 13, 19, 22, 38.
    11
    Dr. Small cited several medical articles in support of his proposed causal mechanism. He
    cited the Kashiwagi14 article to support his position that cytokines IL-6 and TNF-α are produced
    in response to the DPT, Hib, and PCV vaccines and that “brain cells can be abrogated by
    inflammation.” Tr. 81-84; see Pet. Ex. 25 at 3. Dr. Small explained that the Rochfort15 article
    also describes how cytokines IL-6 and TNF-α cause a breakdown of “tight junctions” that keep
    bacteria and toxins away from the central nervous system. Tr. 87-88; Pet. Ex. 26. Dr. Small
    testified that “substances get into parts of the brain where they shouldn’t be” due to the presence
    of these cytokines. Tr. 88.
    Dr. Small also cited Hiraiwa-Sofue,16 a case report of a child who had encephalitis caused
    by a pertussis infection. Tr. 89; Pet. Ex. 27 at 3. The child had a seizure and encephalopathy
    eighteen days after the onset of a pertussis infection. MRI showed “marked demyelination.”
    Pet. Ex. 27 at 1. There was no evidence of direct infection of the pertussis bacteria in the central
    nervous system. The authors suggested several possible mechanisms, including immune
    mediation, proinflammatory cytokine production, pertussis toxin effect on the blood brain
    barrier, and inflammation of the central nervous system. Id. at 3. The authors also stated that
    proinflammatory cytokines were “associated with the development of acute encephalitis.” Id.
    They also noted that levels of IL-6 and another cytokine, IL-10, were higher in the CSF than in
    the blood, suggesting they played a role in the cause of encephalitis. Id.
    Another article cited by Dr. Small is Aydin,17 a case report of an infant who presented
    with seizures and abnormal neurological findings six days after receipt of the whole cell DTP
    vaccination. Pet. Ex. 28. The child was diagnosed with acute necrotizing encephalopathy.
    Possible causal mechanisms included breakdown of the blood brain barrier, “alteration of vessel
    wall permeability,” or “vessel wall necrosis.” Pet. Ex. 28 at 2. The authors hypothesized that the
    vaccine caused increased levels of IL-6 and TNF-α which may have altered “vessel wall
    permeability and local breakdown of the [blood brain barrier].” Id.
    Based on the articles cited, Dr. Small testified that an active infection with bacteria is not
    required in order to have meningoencephalitis; cytokines may be elevated in the cerebrospinal
    14
    Yasuyo Kashiwagi et al., Production of Inflammatory Cytokines in Response to Diphtheria-
    Pertussis-Tetanus (DPT), Haemophilus Influenzae Type b (Hib), and 7-Valent Pneumococcal
    (PCV7) Vaccines, 10 Hum. Vaccines & Immunotherapeutics 667 (2014).
    15
    K.D. Rochfort et al., Downregulation of Blood-Brain Barrier Phenotype by Proinflammatory
    Cytokines Involves NADPH Oxidase-Dependent ROS Generation: Consequences for
    Interendothelial Adherens and Tight Junctions, 9 PLoS One e101815 (2014).
    16
    Ayako Hiraiwa-Sofue et al., Pertussis-Associated Encephalitis/Encephalopathy with Marked
    Demyelination in an Unimmunized Child, 320 J. Neurological Sci. 145 (2012).
    17
    Hale Aydin et al., Acute Necrotizing Encephalopathy Secondary to Diphtheria, Tetanus
    Toxoid and Whole-Cell Pertussis Vaccination: Diffusion-Weighted Imaging and Proton MR
    Spectroscopy Findings, 40 Pediatric Radiology 1281 (2010).
    12
    fluid which cause encephalopathy.18 Tr. 89-91. According to Dr. Small, it is the promotion of
    cytokines, not bacteria, that breaks down the blood brain barrier, causing meningoencephalitis.
    See Tr. 97.
    Next, Dr. Small opined regarding Althen Prong Two, the logical sequence of cause and
    effect—how the Tdap vaccine caused petitioner’s meningoencephalitis. Dr. Small testified that
    prior to vaccination, the petitioner was generally healthy. Petitioner received the vaccine on
    December 2, 2014, and approximately fifteen to sixteen days later became lethargic and
    unresponsive. Tr. 99; Pet. Ex. 9 at 3. He was admitted to the hospital where diagnostic testing
    of his cerebrospinal fluid showed a “clear aseptic meningitis picture” and he was diagnosed with
    meningoencephalitis. Tr. 99. Again, according to Dr. Small, aseptic meningitis indicates an
    inflammatory reaction in the spinal fluid. Tr. 64-65. In support of his opinions, Dr. Small cited
    the petitioner’s treating neurologist who stated that petitioner had meningoencephalitis of
    “unknown cause.” See Pet. Ex. 4(a) at 130-31; Tr. 56. Dr. Small also cited a reference in
    petitioner’s medical record stating that petitioner had aseptic meningitis, which Dr. Small
    explained indicated an inflammatory reaction in the spinal fluid without the presence of virus or
    bacteria. Tr. 64-65.
    Dr. Small further opined that while test results were pending, petitioner was treated
    empirically “for the most common causes of infectious encephalitis” with antivirals and
    antibiotics. Tr. 99. Petitioner had respiratory depression, required a bronchoscopy, but then
    improved. Tr. 100. After discharge, he had depression and cognitive issues. Tr. 100. Dr. Small
    opined that the only “clear and inciting event” was “the proximate relationship of the Tdap
    vaccine.” Id. He opined that “[c]onsidering Mr. Dunn’s prior medical history and subsequent
    medical workup, there is no other suggestive or explainable cause for his meningoencephalitis
    but-for his Tdap vaccination.” Pet. Ex. 9 at 3.
    On cross-examination, Dr. Small conceded that petitioner here did not have evidence of
    demyelination or a pertussis infection, both of which distinguish petitioner’s case from the case
    presented in Hiraiwa-Sofue, described above. Tr. 115; Pet. Ex. 27. Dr. Small agreed that having
    a pertussis infection is very different than receiving the acellular pertussis vaccine that petitioner
    received. Tr. 115. Dr. Small also conceded that the patient in the Aydin case report had
    hemorrhagic necrosis of the deep brain, which petitioner here did not have. Id.; Pet. Ex. 28.
    With regard to Althen Prong Three, Dr. Small opined that the temporal association
    between vaccination and onset of petitioner’s illness was appropriate. He testified that “[i]t takes
    time for the inflammatory reaction to develop” and it is not unusual for an immune response like
    the one he proposes here to take a week or two to occur. Tr. 100-01. The two cases reported in
    Aydin and Hiraiwa-Sofue had onset of six and eighteen days. Therefore, Dr. Small believes that
    petitioner’s onset of fifteen to sixteen days post-vaccination is within the range of expected onset
    given his proposed theory. Tr. 103-04.
    18
    Dr. Small explained that generally there are no commercial tests available to test for cytokines
    in cerebrospinal fluid. Tr. 91.
    13
    Dr. Small was asked to provide medical literature regarding reports of encephalitis and
    meningitis following the Tdap vaccination. See Pet. Ex. 13 at 1-2. In response, he cited an
    article by Dalmau,19 in which the authors discuss encephalitis associated with antibodies against
    the N-methyl-D aspartate receptor (“NMDAR”). Pet. Ex. 11. The pathogenic mechanism of the
    illness is thought to be immune mediated. The article makes a reference to a patient who
    developed anti-NMDAR encephalitis following receipt of the TDaP-IPV (Polio) booster
    vaccination. Pet. Ex. 11 at 5. Dr. Small conceded that petitioner here did not have anti-NMDAR
    encephalitis. Tr. 111.
    Dr. Small also referenced the Baxter study.20 Pet. Ex. 13 at 2; Pet. Ex. 18. That article
    describes acute demyelinating events following vaccines, including acute disseminated
    encephalomyelitis (“ADEM”) after the Tdap vaccine. Dr. Small conceded that petitioner did not
    have ADEM, and that petitioner’s MRI did not show any evidence of demyelination. Tr. 78, 97,
    111-12, 114.
    Dr. Small conceded that there was no epidemiology support for an association between
    the Tdap vaccine and meningoencephalitis. Tr. 114. In an article cited by Dr. Small, authored
    by Singh,21 the most common cause of encephalitis in 139 cases was viral infection (48%),
    followed by autoimmune (22%), and unknown/other (30%). Pet. Ex. 37 at 2. The most common
    viral infection was herpes simplex virus (HSV) at 38.9%, followed by varicella zoster virus
    (VZV) at 23.2%. Id. at 3. Vaccines were not listed in the Singh article as a cause of
    encephalitis.
    As for respondent’s position that petitioner’s illness was caused by reactivation of a prior
    varicella infection, Dr. Small testified that in order to attribute petitioner’s illness to varicella
    reactivation, he would need evidence that petitioner was “infected with varicella-zoster at the
    time of his neurological presentation.” Tr. 107-08. Also, Dr. Small does not believe that
    varicella was the cause of petitioner’s meningoencephalitis because his CSF tested negative for
    the virus. Tr. 107. Additionally, the note by Dr. Hong, stating that the vaccine was the cause of
    petitioner’s illness, influenced Dr. Small’s opinion. Tr. 108.
    On cross-examination, Dr. Small conceded that varicella infection can involve the central
    nervous system. Tr. 112. He also agreed that a patient can first have central nervous system
    involvement with a varicella infection without having any skin lesions. Id. When asked whether
    a patient can have central nervous system involvement with a varicella infection followed by
    19
    Josep Dalmau et al., Clinical Experience and Laboratory Investigations in Patients with Anti-
    NMDAR Encephalitis, 10 Lancet Neurology 63 (2011) (Petitioner filed this article as Exs. 11
    and 16).
    20
    Roger Baxter et al., Acute Demyelinating Events Following Vaccines: A Case-Centered
    Analysis, 63 Clinical Infectious Diseases 1456 (2016).
    21
    Tarun D. Singh et al., The Spectrum of Acute Encephalitis: Causes, Management, and
    Predictors of Outcomes, 84 Neurology 359 (2015).
    14
    skin lesions, Dr. Small answered that he did not know. He deferred to an infectious disease
    physician to answer the question. Id.
    Dr. Small confirmed that the petitioner’s vesicular skin lesions were swabbed on
    December 23, 2014, and that the PCR analysis was positive for the varicella zoster virus. Tr.
    130. He did not know how long it took to obtain the results of the PCR test. Id.
    Importantly, Dr. Small testified that petitioner’s clinical course was “completely
    consistent” with meningoencephalitis caused by varicella. Tr. 123. He also agreed that
    respondent’s theory of causation, varicella infection reactivation, is a known cause of
    encephalitis. Tr. 124. Dr. Small described the mechanism of reactivation very similarly to the
    explanation given by Dr. Sriram. Compare Pet. Ex. 13 at 1-2, with Resp. Ex. E at 1.
    Further, Dr. Small agreed that petitioner’s cerebrospinal fluid showed an elevated white
    blood cell count and elevated protein, and that patients with varicella infection can have these
    findings. Tr. 120. Dr. Small also agreed that petitioner’s varicella zoster IgG was elevated. Tr.
    118-19. Initially, he testified that petitioner’s clinical course was milder than patients he has
    seen with varicella infection and that his patients with the illness had higher white blood cell
    counts, more elevated protein cerebrospinal fluid counts, shingles along the course of nerves in
    the head, and significant brain swelling. Tr. 123-27. However, he later admitted that he also had
    patients with a milder clinical course, like that of petitioner. Tr. 128.
    Lastly, Dr. Small discussed whether AGH and the VA have the ability to share a patient’s
    electronic medical records. He testified that as recent as three months ago it was impossible for
    the two hospitals to share records electronically and this has made treating patients “very
    difficult.” Tr. 119-20.
    b.   Respondent’s Expert, Dr. Sriram22
    Dr. Sriram agrees with Dr. Small as to petitioner’s diagnosis of meningoencephalitis but
    does not believe that petitioner’s Tdap vaccine caused his illness. Tr. 147. Instead, Dr. Sriram
    opines that reactivation of petitioner’s VZV infection caused his meningoencephalitis. Tr. 146;
    Resp. Ex. A at 3.
    Dr. Sriram defined meningoencephalitis as “a clinical diagnosis based to some extent on
    [] laboratory data.” Tr. 146. A patient will have altered mental status which may be associated
    with focal deficits such as hand or leg weakness, speech problems, or seizures. Tr. 147. The
    cerebrospinal fluid may show elevated lymphocytes and protein which indicate inflammation of
    the meninges. Id.
    With regard to petitioner’s theory of causation, Dr. Sriram disagreed with Dr. Small that
    the Tdap vaccine can cause a cytokine reaction which increases the permeability of the blood
    brain barrier. Dr. Sriram testified that there is no evidence to support this hypothesis. See Tr.
    152. Further, Dr. Sriram did not agree that the medical articles cited by Dr. Small support
    22
    Respondent filed six expert reports authored by Dr. Sriram. Resp. Exs. A, E, M, N, P, S.
    15
    petitioner’s causal theory. Dr. Sriram explained that the Kashiwagi study was done to examine
    the effects of the DPT, Hib, and PCV7 vaccines on lymphocytes in peripheral blood. Tr. 148.
    Since the article has nothing to do with the brain, Dr. Sriram does not believe that it supports Dr.
    Small’s theory as it relates to the effect of cytokines on the blood brain barrier. Id. Moreover,
    Dr. Sriram testified that in Kashiwagi, the DTP vaccine decreased cytokine levels, except for a
    marginal increase of IL-6. Id.; Pet. Ex. 25 at fig.1. On cross-examination, however, Dr. Sriram
    agreed that the DTP vaccine caused an elevation of cytokines TNF-α and IL-6, and that he was
    previously mistaken when he testified that there was a decrease in cytokines. Tr. 210.
    As for the Rochfort article cited by petitioner, Dr. Sriram noted that it was an in vitro
    experiment, and thus, it does not speak to what may happen in humans. Tr. 150-52. Rochfort
    was an in vitro experiment where human microvascular endothelial cells were treated with
    cytokines IL-6 and TNF-α, and then studied. Pet. Ex. 26. According to Dr. Sriram, very large
    amounts of cytokines were used. Tr. 150-52. Dr. Sriram testified that researchers have not
    studied whether the blood brain barrier is permeable if a person is injected with high doses of
    cytokines. See Tr. 152.
    Next, Dr. Sriram explained why the Hiraiwa-Sofue and Aydin articles do not support
    petitioner’s theory. He opined that Hiraiwa-Sofue is not relevant because petitioner did not have
    evidence of demyelination, and petitioner is not pursuing a theory based on demyelination. Tr.
    153. The Aydin study involved whole cell pertussis, and here petitioner did not receive a
    vaccine that contained whole cell pertussis, only acellular pertussis. Tr. 154. Moreover,
    petitioner here did not have hemorrhage necrotizing encephalitis, like the patient in Aydin. Id.
    Dr. Sriram emphasized that none of the literature cited by petitioner states that the Tdap
    vaccine can cause a syndrome even close to what petitioner had—Mr. Dunn did not have ADEM
    or NMDAR encephalitis. Tr. 155. Further, Dr. Sriram did not agree that cytokines can cause
    encephalitis. Tr. 214. He explained that cytokines are associated with encephalitis but “are not
    causally connected to it.” Id. Dr. Sriram testified that he has not seen any support in the
    literature to prove that cytokines cause a breakdown of the blood brain barrier in humans. Tr.
    218.
    Next, Dr. Sriram turned his focus to testifying in support of respondent’s position that
    petitioner’s meningoencephalitis was caused by an alternative factor unrelated to his Tdap
    vaccine—petitioner’s VZV infection. General information about VZV infections is set forth in
    the Nagel and Gilden article23 filed by respondent. Resp. Ex. H. VZV is a virus in the herpes
    family. Primary VZV infection generally occurs in childhood among non-vaccinated children
    and is known as chickenpox. Id. at 1. After primary infection, the virus becomes latent in nerve
    ganglia. Id. VZV infection reactivation may cause herpes zoster, also known as shingles. Id.
    VZV reactivation may also cause vasculopathy, meningoencephalitis, cerebellitis, and other
    neurological illnesses. Id. “VZV can reactivate and infect the meninges, brain parenchyma and
    nerve roots to produce a VZV meningoencephalitis.” Id. at 4.
    23
    Maria A. Nagel & Don Gilden, Neurological Complications of Varicella Zoster Virus
    Reactivation, 27 Current Opinion Neurology 356 (2014).
    16
    With regard to Althen Prong One, a medical theory of causation, Dr. Sriram’s opinions
    were consistent with the information about VZV set forth in Nagel and Gilden. He explained
    that the herpes zoster virus is present in the ganglion cells of the body. Tr. 156. The virus
    resides in the neurons of the ganglion cells, and for reasons that are not clearly understood, the
    virus becomes activated. Id. One trigger for activation is immunosuppression, which is more
    common in persons as they become older, and also is “classic” in those between ages forty-five
    to fifty. Id. The virus that resides in the ganglion cells can either “come forward and cause
    infection of the skin or they go backwards and infect the meninges and the brain.” Tr. 157.
    Persons who had chickenpox have the virus in their nerve cells, and it remains present
    throughout life. The virus can become activated and travel “proximally into the spinal cord or []
    brain or distally out into the skin.” Tr. 157-58. It is not uncommon for viral reactivation to
    cause both encephalitis and meningitis. Id. Dr. Sriram further explained that with herpes zoster
    reactivation, the virus can affect both the skin and nervous system. Id. VZV is a known cause,
    and the second leading cause of, viral encephalitis.24 Resp. Ex. E at 2.
    In support of his theory of causation, Dr. Sriram cited several medical articles. A number
    of which support his opinion that VZV can cause central nervous system illnesses, including
    encephalitis and meningitis, through the mechanism of reactivation. In Grahn and Studahl,25 the
    authors state that VZV is the “second most common infectious etiology of encephalitis after the
    herpes simplex virus.” Resp. Ex. F at 2. The authors describe the mechanism as follows: VZV
    is a herpes virus that may become latent in neurons in the dorsal root, autonomic, and cranial
    ganglia. Id. Reactivation of the virus may infect the skin, and central nervous system, causing
    encephalitis and meningitis. Id. And in Nagel and Gilden, the authors state that VZV can travel
    to the central nervous system to produce meningoencephalitis, as described by Dr. Sriram. Resp.
    Ex. H at 1; Tr. 160.
    Dr. Small also recognizes the theory of herpes zoster reactivation, and his explanation of
    the mechanism did not differ from that provided by Dr. Sriram. See Pet. Ex. 13 at 1-2; Tr. 171.
    With regard to Althen Prong Two, a logical sequence of cause and effect, Dr. Sriram
    testified that petitioner had herpes zoster which infected his central nervous system, causing
    encephalitis and meningitis (meningoencephalitis), via the mechanism of viral reactivation. Tr.
    156. Dr. Sriram provided several reasons why the evidence supported his opinion that
    petitioner’s VZV infection was the more likely cause of his meningoencephalitis. First,
    petitioner had acute encephalopathy and his cerebrospinal fluid revealed elevated lymphocytes
    and protein consistent with VZV meningoencephalitis. Tr. 163-64. Dr. Sriram cited the
    24
    See Don Gilden et al., Varicella Zoster Virus Vasculopathies: Diverse Clinical Manifestations,
    Laboratory Features, Pathogenesis, and Treatment, 8 Lancet Neurology 731 (2009); T. De
    Broucker et al., Acute Varicella Zoster Encephalitis Without Evidence of Primary Vasculopathy
    in a Case-Series of 20 Patients, 18 Clinical Microbiology Infection 808 (2011).
    25
    Anna Grahn & Marie Studahl, Varicella-Zoster Virus Infections of the Central Nervous
    System – Prognosis, Diagnostics and Treatment, 71 J. Infection 281 (2015).
    17
    Gregoire study26 to establish that there can be a wide range in the number of lymphocytes present
    in the cerebrospinal fluid of patients with meningoencephalitis. Resp. Ex. C at 2 tlb.1. In
    Gregoire, one patient had 13 and another patient had 358 lymphocytes in their CSF. Id.; Tr. 162-
    63. Dr. Sriram explained that the presence of and number of lymphocytes (indicating
    inflammation) in the CSF depends at what point in the illness the spinal fluid is drawn. Tr. 163.
    The second basis for Dr. Sriram’s Althen Prong Two opinion is that petitioner had a rash
    on his chest noted December 23, and a swab of the rash tested by PCR was positive for VZV.27
    Dr. Sriram cited medical articles which supported his position that a patient can have central
    nervous system symptoms with no rash, or the neurological symptoms can be followed by the
    rash. In Nagel,28 the authors addressed the issue of whether the herpes zoster rash must be
    present for the virus to cause illness. Resp. Ex. O. The authors reviewed 30 cases of VZV
    vasculopathy, which caused stroke due to viral infection of the cerebral arteries. Id. at 1. A
    herpes zoster rash occurred in 19 out of the 30 cases. The authors concluded that the herpes
    zoster rash was “not required to diagnose varicella zoster virus vasculopathy.” Id.
    A positive CSF PCR is not required to find that a patient has VZV encephalitis. The
    Gilden article states, “[a]lthough a positive PCR for VZV DNA in CSF is helpful, a negative
    PCR does not exclude the diagnosis . . .” Resp. Ex. T at 3. Dr. Sriram explained that “[w]hile
    the specificity of [a] PCR assay for VZV is 100% [there are no false positive PCR values], the
    sensitivity varies.” Resp. Ex. E at 2. A PCR done either very early or very late during the
    clinical course of encephalitis may be negative. Id. A negative PCR study does not exclude the
    diagnosis of VZV encephalitis. Resp. Ex. N at 2; see also Resp. Ex. T at 3.
    Dr. Sriram cited a paper by De Broucker. Resp. Ex. G. There, four out of twenty
    patients had a negative cerebrospinal fluid PCR for VZV but had a herpes zoster rash before or
    after onset of acute VZV encephalitis. Id. at 1. As it relates to the timing of the herpes zoster
    rash, the authors state that “neurological presentations can also appear with, precede, or follow
    herpes zoster.” Id. Dr. Sriram also cited the Grahn and Studahl article, which states that “the
    central nervous system manifestations might occur before the skin eruptions.” Resp. Ex. F at 2.
    Dr. Sriram agreed that based on the criteria set forth in De Broucker, petitioner would not
    have qualified as a “confirmed” case of VZV encephalitis because he did not have a positive
    cerebrospinal fluid PCR for VZV. Tr. 199. Dr. Sriram affirmed that in De Broucker, the authors
    26
    S. S. Gregoire et al., Polymerase Chain Reaction Analysis and Oligoclonal Antibody in the
    Cerebrospinal Fluid from 34 Patients with Varicella-Zoster Virus Infection of the Nervous
    System, 77 J. Neural Neurosurgery Psychiatry 938 (2006).
    27
    Dr. Sriram believes it is likely that petitioner had the zoster rash before December 23, but it
    was not detected. Tr. 164, 225. However, even if the zoster rash was not present until it was
    seen on December 23, Dr. Sriram’s opinion would be the same. Tr. 225.
    28
    Maria A. Nagel et al., The Varicella Zoster Virus Vasculopathies: Clinical, CSF, Imaging, and
    Virologic Features, 70 Neurology 853 (2008).
    18
    stated that the only way to confirm VZV is by a positive CSF PCR or evidence of antibodies to
    VZV.29 Tr. 201. In Arruti,30 the authors distinguish between “confirmed” and “probable” or
    “suspected” VZV-caused illness. Resp. Ex. J at 2. While a confirmed case is defined as one
    with positive cerebrospinal fluid PCR testing, a patient probably has VZV infection if there is a
    simultaneous rash or a rash that occurs shortly after illness onset and there are inflammatory
    markers in the CSF. Tr. 203.
    In Arruti, the authors studied the clinical characteristics of central nervous system
    infections caused by VZV in 280 older patients (over age 65). Resp. Ex. J at 1. The authors
    discussed the incidence of varicella zoster central nervous system infections, stating that “VZV is
    a common viral agent causing central nervous system infections in the adult population, using
    ranking behind HSV.” Id. at 7. The authors also discuss the incidence of skin lesions in the
    context of central nervous system infections caused by VZV:
    Previous studies have shown that neurological complications of HZ [herpes
    zoster] can occur without skin lesions, such complications being observed in 38 to
    69% of patients with no skin involvement (cites omitted). In our study, only
    16.7% of patients had no signs of skin involvement. Hence, our data indicate that
    HZ [herpes zoster] occurring simultaneously or shortly after CNS [central nervous
    system] neurological symptoms suggests causality in a high percentage of cases in
    the elderly. . . . In the eight patients with probable VZV encephalitis and no viral
    confirmation [PCR negative for VZV], the clinical syndrome in combination with
    skin involvement [the presence of an HZ rash] together with imaging and/or
    cerebrospinal fluid findings supported the diagnosis and suggested a causative
    link.
    Id. Thus, based on Arruti, Dr. Sriram opines that petitioner would fall into the probable
    category. Tr. 203.
    Lastly, Dr. Sriram testified that petitioner’s elevated VZV titer ˃4000, was a value
    considered to be a striking elevation and confirmed recent activation of the varicella virus.31 Tr.
    167-70.
    29
    Dr. Sriram filed the Gregoire article to support his testimony that if a PCR of cerebrospinal
    fluid is negative for VZV, an anti-VZV specific antibody test may be performed to confirm
    diagnosis, but this test was not ordered for petitioner. Tr. 161-62; Resp. Ex. C at 1.
    30
    Maialen Arruti et al., Incidence of Varicella Zoster Virus Infections of the Central Nervous
    System in the Elderly: A Large Tertiary Hospital-Based Series, 23 J. Neurovirology 451 (2017).
    31
    Dr. Sriram testified that although the VZV titer is high, because he does not know petitioner’s
    baseline level, this fact alone does not form the basis of his causation opinion but is consistent
    with it. Tr. 224.
    19
    When asked how long it would take to perform swab PCR test, Dr. Sriram answered that
    if the test is sent to an outside laboratory, it would take three to five days to obtain the results.
    Tr. 170. Dr. Sriram testified that based on petitioner’s medical records, it appeared that the PCR
    swab test was sent out LabCorp in North Carolina on December 23. See Pet. Ex. 4(d) at 758.
    As for Althen Prong Three, Dr. Sriram opined that the timing between vaccination and
    illness onset was appropriate for the VZV to cause petitioner’s meningoencephalitis. Tr. 170-71.
    Dr. Sriram emphasized that when a person with shingles and altered mental status also has
    cerebrospinal fluid that shows inflammation, “the preponderance of the clinical opinion would be
    this is a zoster meningoencephalitis.” Tr. 171. Dr. Sriram cited the study by Science,32 which
    studied eighty-four children with VZV neurological complications. Resp. Ex. U at 2. Children
    were included in the study if the onset of their neurological symptoms occurred four weeks
    before or after the VZV rash. Id. The “median interval between onset of rash and onset of
    neurological manifestations was 5 days (range 6 days before to 16 days after the appearance of
    the rash).” Id. at 3.
    On cross-examination, Dr. Sriram was questioned about the note made by Dr. Hong, one
    of petitioner’s treating physicians at the VA. Dr. Sriram did not agree that the following note by
    Dr. Hong was an opinion that the Tdap vaccine caused petitioner’s illness. On February 4, 2015,
    the title of Dr. Hong’s note is “Allergy & Immunology Adverse Event Note.” Pet. Ex. 5(b) at
    296. It states that petitioner “was admitted to AGH on 12/19/2014 with AMS. LP shows aseptic
    meningitis result. Had Tdap vaccine on 12/2/2014.” Id. Dr. Sriram did agree that this note and
    other entries in the VA records referenced that petitioner had an allergy or adverse drug reaction
    to Tdap. Tr. 188.
    Dr. Sriram explained that according to the AGH records, the PCR swab test of petitioner’s
    vesicle was sent out for testing on December 23. December 25 was a holiday, and petitioner was
    discharged on December 27.33 Dr. Sriram testified that it was “highly unlikely” that the PCR test
    results (positive for VZV) would have come back the day after Christmas in time for someone to
    review it and make an assessment or recommendation about the diagnosis prior to the patient’s
    discharge.34 Tr. 189.
    32
    Michelle Science et al., Central Nervous System Complications of Varicella-Zoster Virus, 165
    J. Pediatrics 779 (2014).
    33
    During his testimony, Dr. Sriram stated petitioner was discharged on December 26. Tr. 189.
    Petitioner was actually discharged on December 27.
    34
    After the hearing, the PCR swab test results from LabCorp were filed. Pet. Ex. 39. They
    showed the test report date was December 30, 2014. Thus, it appears Dr. Sriram was correct that
    the results were not available before the petitioner’s hospital discharge on December 27.
    20
    V.     LEGAL FRAMEWORK
    A.   Standards for Adjudication
    The Vaccine Act was established to compensate vaccine-related injuries and deaths. §
    300aa-10(a). “Congress designed the Vaccine Program to supplement the state law civil tort
    system as a simple, fair and expeditious means for compensating vaccine-related injured persons.
    The Program was established to award ‘vaccine-injured persons quickly, easily, and with
    certainty and generosity.’” Rooks v. Sec’y of Health & Human Servs., 
    35 Fed. Cl. 1
    , 7 (1996)
    (quoting H.R. Rep. No. 908 at 3, reprinted in 1986 U.S.C.C.A.N. at 6287, 6344).
    Petitioner’s burden of proof is by a preponderance of the evidence. § 300aa-13(a)(1).
    The preponderance standard requires a petitioner to demonstrate that it is more likely than not
    that the vaccine at issue caused the injury. Moberly v. Sec’y of Health & Human Servs., 
    592 F.3d 1315
    , 1322 n.2 (Fed. Cir. 2010). Proof of medical certainty is not required. Bunting v.
    Sec’y of Health & Human Servs., 
    931 F.2d 867
    , 873 (Fed. Cir. 1991). In particular, petitioners
    must prove that that the vaccine was “not only [the] but-for cause of the injury but also a
    substantial factor in bringing about the injury.” Moberly, 
    592 F.3d at 1321
     (quoting Shyface v.
    Sec’y of Health & Human Servs., 
    165 F.3d 1344
    , 1352-53 (Fed. Cir. 1999)); Pafford v. Sec’y of
    Health & Human Servs., 
    451 F.3d 1352
    , 1355 (Fed. Cir. 2006). A petitioner who satisfies this
    burden is entitled to compensation unless respondent can prove, by a preponderance of the
    evidence, that the vaccinee’s injury is “due to factors unrelated to the administration of the
    vaccine.” § 300aa-13(a)(1)(B).
    B. Causation
    To receive compensation under the Program, petitioner must prove either: (1) that he
    suffered a “Table Injury”—i.e., an injury listed on the Vaccine Injury Table—corresponding to a
    vaccine that he received, or (2) that he suffered an injury that was actually caused by a
    vaccination. See §§ 300aa-13(a)(1)(A) and 11(c)(1); Capizzano v. Sec’y of Health & Human
    Servs., 
    440 F.3d 1317
    , 1319-20 (Fed. Cir. 2006). 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.”
    Moberly, 
    592 F.3d at 1321
     (quoting Shyface, 
    165 F.3d at 1352-53
    ).
    Because petitioner does not allege that he suffered a Table injury, he must prove that the
    vaccine he received caused his injury. To do so, he must establish, by preponderant evidence:
    (1) a medical theory causally connecting the vaccine and injury (“Althen Prong One”); (2) a
    logical sequence of cause and effect showing that the vaccine was the reason for the injury
    (“Althen Prong Two”); and (3) a showing of a proximate temporal relationship between the
    vaccine and injury (“Althen Prong Three”). § 300aa-13(a)(1); Althen, 
    418 F.3d at 1278
    .
    The causation theory must relate to the injury alleged. Thus, petitioner must provide a
    reputable medical or scientific explanation that pertains specifically to this case, although the
    explanation need only be “legally probable, not medically or scientifically certain.” Knudsen v.
    Sec’y of Health & Human Servs., 
    35 F.3d 543
    , 548-49 (Fed. Cir. 1994). Petitioner cannot
    establish entitlement to compensation based solely on assertions. Rather, a vaccine claim must
    21
    be supported either by medical records or by the opinion of a medical doctor. § 300aa-13(a)(1).
    In determining whether petitioner is entitled to compensation, the special master shall consider
    all material contained in the record, including “any . . . conclusion, [or] medical judgment . . .
    which is contained in the record regarding . . . causation.” § 300aa-13(b)(1)(A). The
    undersigned must weigh the submitted evidence and the testimony of the parties’ offered experts
    and rule in petitioner’s favor when the evidence weighs in his favor. See Moberly, 
    592 F.3d at 1325-26
     (“Finders of fact are entitled—indeed, expected—to make determinations as to the
    reliability of the evidence presented to them and, if appropriate, as to the credibility of the
    persons presenting that evidence”); see also Althen, 
    418 F.3d at 1280
     (providing “close calls” are
    resolved in petitioner’s favor).
    Another important aspect of the causation-in-fact case law under the Vaccine Act
    concerns the factors that a special master should consider in evaluating the reliability of expert
    testimony and other scientific evidence relating to causation issues. In Daubert v. Merrell Dow
    Pharmacy, Inc., 
    509 U.S. 579
     (1993), the United States Supreme Court listed certain factors that
    federal trial courts should utilize in evaluating proposed expert testimony concerning scientific
    issues. In Terran v. Secretary of Health & Human Services., 
    195 F.3d 1302
    , 1316 (Fed. Cir.
    1999), the Federal Circuit ruled that it is appropriate for special masters to utilize Daubert’s
    factors as a framework for evaluating the reliability of causation-in-fact theories actually
    presented in Program cases.
    The Daubert factors for analyzing the reliability of testimony are: (1) whether a theory or
    technique can be (and has been) tested; (2) whether the theory or technique has been subjected to
    peer review and publication; (3) whether there is a known or potential rate of error and whether
    there are standards for controlling the error; and (4) whether the theory or technique enjoys
    general acceptance within a relevant scientific community. Terran, 
    195 F.3d at 1316
    , n.2 (citing
    Daubert, 
    509 U.S. at 592-95
    ). In addition, where both sides offer expert testimony, a special
    master’s decision may be “based on the credibility of the experts and the relative persuasiveness
    of their competing theories.” Broekelschen v. Sec’y of Health & Human Servs., 
    618 F.3d 1339
    ,
    1347 (Fed. Cir. 2010) (citing Lampe v. Sec’y of Health & Human Servs., 
    219 F.3d 1357
    , 1362
    (Fed. Cir. 2000)). However, nothing requires the acceptance of an expert’s conclusion
    “connected to existing data only by the ipse dixit of the expert,” especially if “there is simply too
    great an analytical gap between the data and the opinion proffered.” Snyder v. Sec’y of Health
    & Human Servs., 
    88 Fed. Cl. 706
    , 743 (2009) (quoting Gen. Elec. Co. v. Joiner, 
    522 U.S. 146
    (1997)).
    In deciding the issues in this case, the undersigned has considered the record as a whole.
    § 300aa-13(a)(1). The undersigned has reviewed and relied on statements in the medical records,
    as medical records are generally viewed as trustworthy evidence, since they are created
    contemporaneously with the treatment of the vaccinee. Cucuras v. Sec’y of Health & Human
    Servs., 
    993 F.2d 1525
    , 1528 (Fed. Cir. 1993). In addition, the treating physicians’ opinions are
    “quite probative,” as treating physicians are in the “best position” to evaluate the vaccinee’s
    condition. Capizzano, 
    440 F.3d at 1326
    . However, no treating physician’s views bind the
    special master, per se; rather, their views should be carefully considered and evaluated. § 300aa-
    13(b)(1); Snyder, 88 Fed. Cl. at 745 n.67. Each opinion from a treating physician should be
    weighed against other, contrary evidence present in the record—including conflicting opinions
    22
    from other treating physicians. Hibbard v. Sec’y of Health & Human Servs., 
    100 Fed. Cl. 742
    ,
    749 (2011), aff’d, 
    698 F.3d 1355
     (Fed. Cir. 2012); Caves v. Sec’y of Health & Human Servs.,
    
    100 Fed. Cl. 119
    , 136 (2011), aff’d, 463 F. App’x. 932 (Fed. Cir. 2012); Veryzer v. Sec’y of
    Health & Human Servs., No. 06-522V, 
    2011 WL 1935813
    , at *17 (Fed. Cl. Spec. Mstr. Apr. 29,
    2011), mot. for rev. denied, 
    100 Fed. Cl. 344
     (2011).
    C. Alternative Causation
    A petitioner who satisfies his burden of proof under the standards set forth above is
    entitled to compensation unless respondent can prove, by a preponderance of the evidence, that
    the vaccinee’s injury is “due to factors unrelated to the administration of the vaccine.” § 300aa-
    13(a)(1)(B). Therefore, in this case, even if petitioner met his burden of proof on causation, he is
    not entitled to compensation where the respondent has proven by preponderant evidence that a
    factor unrelated to the vaccination caused his meningoencephalitis. See Doe v. Sec’y of Health
    & Human Servs., 
    601 F.3d 1349
    , 1358 (Fed. Cir. 2010) (“[Petitioner] Doe never established a
    prima facie case, so the burden (and attendant restrictions on what ‘factors unrelated’ the
    government could argue) never shifted.”). The Vaccine Act provides that “factors unrelated to
    the administration of the vaccine,” are those “which are shown to have been the agent . . .
    principally responsible for causing the petitioner’s illness, disability, injury, condition or death.”
    § 300aa-13(a)(2)(B).
    In Munn, the Federal Circuit affirmed the special masters’ findings of alternate causation.
    The special master “concluded that ‘[petitioner] succumbed to infection’ and thus that the
    pneumonia led to her death” not the encephalopathy alleged to be caused by the vaccination.
    Munn v. Sec’y of Health & Human Servs., 
    970 F.2d 863
    , 872 (Fed. Cir. 1992).
    Here, respondent has identified an alternative cause of petitioner’s illness: Reactivation of
    VZV infection. Thus, the undersigned undertakes an analysis based on the Althen prongs as to
    whether VZV reactivation—a factor unrelated to petitioner’s vaccination—caused petitioner’s
    meningoencephalitis. See Forrest v. Sec’y of Health & Human Servs., No. 14-1046V, 
    2019 WL 925495
    , at *1 (Fed. Cl. Spec. Mstr. Jan. 28, 2019) (finding respondent showed by preponderant
    evidence that a VZV infection was responsible for petitioner’s injury).
    VI.    Alternative Factor Analysis
    A. Althen Prong One: Respondent’s Medical Theory
    Under Althen Prong One, respondent must set forth a medical theory explaining how
    VZV infection reactivation can cause meningoencephalitis. Andreu v. Sec’y of Health & Human
    Servs., 
    569 F.3d 1367
    , 1375 (Fed. Cir. 2009); Pafford, 451 F.3d at 1355-56. The theory of
    causation must be informed by a “sound and reliable medical or scientific explanation.”
    Knudsen, 
    35 F.3d at 548
    ; see also Veryzer v. Sec’y of Health & Human Servs., 
    98 Fed. Cl. 214
    ,
    223 (2011) (noting that special masters are bound by both § 300aa-13(b)(1) and Vaccine Rule
    8(b)(1) to consider only evidence that is both “relevant” and “reliable”). If respondent relies
    upon a medical opinion to support his theory, the basis for the opinion and the reliability of that
    basis must be considered in the determination of how much weight to afford the offered opinion.
    23
    See Broekelschen, 
    618 F.3d at 1347
     (“The special master’s decision often times is based on the
    credibility of the experts and the relative persuasiveness of their competing theories.”); Perreira
    v. Sec’y of Health & Human Servs., 
    33 F.3d 1375
    , 1377 n.6 (Fed. Cir. 1994) (“Expert opinion is
    no better than the soundness of the reasons supporting it.” (citing Fehrs v. United States, 
    620 F.2d 255
    , 265 (Ct. Cl. 1980))).
    Respondent’s proposed mechanism of causation is varicella zoster viral reactivation. The
    mechanism is not disputed by petitioner’s expert. Further, the experts do not disagree with
    petitioner’s diagnosis, meningoencephalitis, and they both agree that VZV infection can cause
    this illness. Respondent’s proposed mechanism is a sound and reliable explanation of
    pathogenesis as illustrated by the testimony of both experts and the medical literature filed by
    respondent. Therefore, the undersigned finds that respondent has established by preponderant
    evidence that VZV reactivation can cause meningoencephalitis.
    B. Althen Prong Two: Logical Sequence of Cause and Effect
    Under Althen Prong Two, respondent must prove by a preponderance of the evidence that
    there is a “logical sequence of cause and effect showing that the vaccination was the reason for
    the injury.” Capizzano, 
    440 F.3d at 1324
     (quoting Althen, 
    418 F.3d at 1278
    ). Respondent must
    show “that the vaccine was the ‘but for’ cause of the harm . . . or in other words, that the vaccine
    was the ‘reason for the injury.’” Pafford, 451 F.3d at 1356 (citations omitted).
    The central issue here is not whether VZV reactivation can cause meningoencephalitis, but
    whether it did in petitioner’s case. The undersigned finds that respondent has proven by
    preponderant evidence that it did for the following reasons.
    Petitioner had chickenpox as a child. His clinical course was consistent with
    meningoencephalitis caused by VZV. Petitioner had altered mental status, his CSF analysis was
    consistent with inflammation caused by a viral infection, he had an abnormal and elevated VZV
    titer, and he had skin vesicle which tested positive for the virus. Moreover, the medical literature
    shows that next to the herpes simplex virus, VZV is the second leading cause of viral
    meningoencephalitis. And further, Dr. Small agreed that petitioner’s clinical course was
    “completely consistent” with VZV infection. Tr. 123.
    Dr. Small testified that in order to diagnose petitioner with VZV caused illness, he would
    need to see evidence that petitioner was infected with the virus at the time he presented with
    neurological symptoms. When asked whether a patient could first have central nervous system
    involvement, followed by a skin rash, Dr. Small stated that he did not know. Medical literature
    filed by respondent answered the question. Articles by De Broucher, Grahn and Studhal, and
    Arruti all state that neurological manifestations may occur before the skin vesicles of herpes
    zoster appear. The fact that several articles address this issue suggest that the factual
    circumstances here, where the rash occurs after the neurological symptoms, is not unique to this
    petitioner.
    Petitioner’s onset of altered mental status was December 19, and his herpes zoster rash
    was present on December 23, while petitioner was still encephalopathic. Thus, he had
    24
    neurological symptoms and a rash at the same time. The Arruti article speaks to this exact
    scenario. Their patient data indicated that the herpes zoster rash occurred either “simultaneously
    or shortly after CNS [central nervous system] neurological symptoms.” Resp. Ex. J at 7.
    In addition to the support from medical articles, the petitioner’s medical records also offer
    support for Dr. Sriram’s position that the rash can follow central nervous system symptoms. On
    December 23, an infectious disease physician charted that, “skin lesions in VZV encephalitis
    may develop after AMS even during [treatment].” Pet. Ex. 4(a) at 35. This contemporaneous
    note is persuasive evidence in support of respondent’s position.
    With regard to medical record entries by Dr. Hong and Dr. Pae, attributing petitioner’s
    illness to the Tdap vaccine, the undersigned finds these references are not persuasive evidence of
    causation based on the totality of the facts and circumstances. Dr. Hong and Dr. Pae could not
    have been informed by the petitioner that he had a positive skin test for herpes zoster, because at
    the time the petitioner saw these doctors, he did not know that information. Neither of these
    physicians saw nor treated the petitioner while he was a patient at AGH. Dr. Hong and Dr. Pae
    treated the petitioner after his discharge from AGH, when he presented for follow-up care at the
    VA. Neither of these physicians reference the positive PCR skin test results in their records.
    Based on Dr. Small’s testimony, it would have been difficult, if not impossible, for them to
    review the petitioner’s AGH record. Tr. 119. If Dr. Hong or Dr. Pae had reviewed the
    petitioner’s positive VZV skin test results, which was very important and relevant data that could
    inform their opinions as to causation, it is likely that at least one of them would have noted the
    results. Lastly, the LabCorp report date is December 30, three days after petitioner’s discharge
    from AGH. Based on the available record, it does not appear the report was seen by either Dr.
    Hong or Dr. Pae.
    The undersigned generally finds opinions of a treating physician to be persuasive evidence
    of causation, but for all of the reasons stated above, Dr. Hong’s statement about Tdap causation
    is not persuasive here. The far more sound and reliable evidence as to causation specific to
    petitioner’s case is that offered by respondent and Dr. Sriram.
    The undersigned does find the contemporaneous records created by the physicians at AGH
    to be persuasive. On approximately twelve occasions, the treating physicians suggest that the
    etiology of petitioner’s illness is “likely viral” or “infectious.” See, e.g. Pet Ex. 4(a) at 9-62.
    This information, along with all of the reasons discussed above, combine to provide
    preponderant evidence that petitioner’s illness was caused by VZV infection reactivation.
    C. Althen Prong Three: Proximate Temporal Relationship
    Under Althen Prong Three, respondent must provide “preponderant proof that the onset
    of symptoms occurred within a timeframe for which, given the understanding of the disorder’s
    etiology, it is medically acceptable to infer causation-in-fact.” De Bazan v. Sec’y of Health &
    Human Servs., 
    539 F.3d 1347
    , 1352 (Fed. Cir. 2008). The acceptable temporal association will
    vary according to the particular medical theory advanced in the case. See Pafford, 451 F.3d at
    1358. A temporal relationship between a vaccine and an injury, standing alone, does not
    constitute preponderant evidence of vaccine causation. See, e.g., Veryzer, 100 Fed. Cl. at 356
    25
    (explaining that “a temporal relationship alone will not demonstrate the requisite causal link” and
    there must be “a medical theory causally connecting the vaccine and injury”).
    The onset of petitioner’s altered mental status occurred on December 19, and his herpes
    zoster skin rash was present on December 23. Based on testimony of Dr. Sriram, and the journal
    articles by Arruti, De Broucker, Grahn and Stadahl, and Science, the timeline of illness and rash
    is consistent with the clinical course of VZV meningoencephalitis occurring with viral
    reactivation. Thus, the undersigned finds the respondent has proven by preponderant evidence
    that the temporal association between the mechanism of reactivation on the onset of illness is
    appropriate.
    VII.   CONCLUSION
    It is clear from the medical records that Mr. Dunn suffered as a result of his illness, and
    the undersigned extends her sympathy to him. However, this case cannot be decided based upon
    sympathy but rather by an analysis of the evidence.
    For all of the reasons discussed above, the undersigned finds that respondent has
    established by preponderant evidence a factor unrelated to vaccination caused petitioner’s illness.
    Therefore, petitioner is not entitled to compensation and his petition must be dismissed. In the
    absence of a timely filed motion for review pursuant to Vaccine Rule 23, the Clerk of the Court
    SHALL ENTER JUDGMENT in accordance with this Decision.
    IT IS SO ORDERED.
    s/Nora Beth Dorsey
    Nora Beth Dorsey
    Special Master
    26