Bickel v. Secretary of Health and Human Services

In the United States Court of Federal Claims No. 21-867 (Filed: 29 July 2026) * *************************************** ALLEN BICKEL, * * Petitioner, * * v. * * SECRETARY OF HEALTH AND HUMAN * SERVICES, * * Respondent. * * *************************************** Jennifer Anne Gore Maglio, Mctlaw, of Sarasota, FL, for petitioner. Austin Egan, Trial Attorney, with whom were Alexis B. Babcock, Assistant Director, Heather L. Pearlman, Deputy Director, Jonathan D. Guynn, Acting Director, Torts Branch, and Brett A. Shumate, Assistant Attorney General, Civil Division, Department of Justice, all of Washington, DC, for the government. OPINION AND ORDER HOLTE, Judge. “‘[W]hile most of the Nation[] . . . enjoy[s] great[] benefit from immunization programs, a small but significant number have been gravely injured.’” Cloer v. Sec’y of Health & Hum Servs., 654 F.3d 1322, 1325 (Fed. Cir. 2011) (quoting H.R. Rep. No. 99-908 at 4 (1986)); see also Boatmon v. Sec’y of Health & Hum. Servs., 941 F.3d 1351, 1364 (Fed. Cir. 2019) (Newman, J., dissenting) (quoting National Childhood Vaccine-Injury Compensation Act: Hearing on S.2117 Before the S. Comm. on Labor & Hum. Res., 98th Cong. 2 (1984) (statement of Sen. Orrin Hatch, S. Comm. on Labor & Hum. Res.) (“Senator Hatch cautioned, there is ‘a small but significant public health problem—the incidence of harmful and occasionally even fatal reactions to vaccines administered’”)). “These few but important injuries create doubts and fears in our National Childhood Vaccination Programs.” Boatmon, 941 F.3d at 1364 (quoting National Childhood Vaccine-Injury Compensation Act: Hearing on S.2117 Before the S. Comm. on Labor & Human Res., 98th Cong. at 3–4) (statement of Sen. Edward Kennedy, S. Comm. on * This opinion was initially filed under seal on 21 July 2026 pursuant to Vaccine Rule 18(b) of the Rules of the Court of Federal Claims. The Court provided the parties time to submit proposed redactions in accordance with Rule 18(b). Both parties confirmed they do not propose any redactions. This opinion is now reissued for publication in its original form. Labor & Human Res.). “‘[F]or the relatively few who are injured by vaccines,’” Congress determined the “‘opportunities for redress and restitution [were] limited, time-consuming, [and] expensive.’” Cloer, 654 F.3d at 1325 (quoting H.R. Rep. No. 99-908, at 6 (1986)). Congress, therefore, “created the Vaccine Program” to “compensate injured persons quickly and fairly” for injuries “either presumed or proven to be causally connected to vaccines.” Id. This case turns on the Chief Special Master’s rejection of petitioner’s “medical theory causally connecting the vaccination and the injury,” as required for compensation in Althen v. Sec’y of Health & Hum. Servs., 418 F.3d 1274, 1278 (Fed. Cir. 2005). In defining this legal standard, Althen and its progeny took care to keep the Vaccine Program quick and fair by clarifying: a “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.” Andreu v. Sec’y of Health & Hum. Servs., 569 F.3d 1367, 1380 (Fed. Cir. 2009) (citations omitted) (emphasis in original). Nonetheless, while the Federal Circuit has found “medical plausibility” too stringent a standard for a medical theory, see id. at 1379, it has also found legal plausibility too lax a standard, see Cerrone v. Sec’y of Health & Hum. Servs., 146 F.4th 1113, 1121 n.3 (Fed. Cir. 2025). Of importance, Federal Circuit precedent does provide guidance for evaluating a theory of causation when tension exists between medical consensus and the legal standard of preponderance of the evidence: While [a] case [may] involve[] the possible link between . . . vaccination and . . . injury, a sequence hitherto unproven in medicine, 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. Althen, 418 F.3d at 1280. Despite this guidance, difficult distinctions between medical standards and legal standards of proof have resulted in inconsistent findings among special masters on identical questions—for example, in this case, the Chief Special Master found a tetanus-diphtheria-acellular-pertussis vaccine cannot cause Guillain Barré Syndrome but acknowledged other special masters have found the opposite. See Section IX.B, infra. Earlier this year, the Federal Circuit, concerned over inconsistent results in a Vaccine Program designed to compensate injured persons quickly and fairly, directed this court to “adopt[] . . . a related-case rule or other mechanisms to avoid inconsistent rulings of the special masters.” Gamboa-Avila v. Sec’y of Health & Hum. Servs., 166 F.4th 1318, 1324 (Fed. Cir. 2026). As the Supreme Court observed in Kisor v. Wilkie, there are “well-known benefits of uniformity in interpreting genuinely ambiguous rules . . . [as] judges are most likely to come to divergent conclusions when they are least likely to know what they are doing.” 588 U.S. 558, 572 (2019). In other words, the best solution to inconsistent rulings is a clear legal standard. See id. In the absence of a clear legal standard, the Court must still apply the best “mechanism to avoid inconsistent rulings” for this case: Federal Circuit precedent defining the legal standard. See Section IX, infra. The background for this case is straightforward. In early May 2019, petitioner suffered an upper respiratory infection. On 24 May 2019, petitioner received a tetanus-diphtheria- acellular-pertussis vaccine following a dog bite. Petitioner began experiencing neuropathy and muscle cramps in early June 2019, was admitted to the hospital for worsening symptoms in July 2 2019, and was ultimately diagnosed with Guillain Barré Syndrome in December 2019. In February 2021, Mr. Bickel filed a petition for compensation, alleging his tetanus-diphtheria- acellular-pertussis vaccine caused his Guillain Barré Syndrome. Petitioner later provided expert reports and medical literature to propose “molecular mimicry” as his “medical theory causally connecting the vaccination and the injury.” Five years after Mr. Bickel filed his petition, on 23 January 2026, Chief Special Master Corcoran denied petitioner compensation, concluding “more must be provided to show molecular mimicry is a reasonable mechanistic explanation for an autoimmune process.” Petitioner filed a Motion for Review, arguing the Chief Special Master failed to set forth a rational basis to deny compensation. For the following reasons, the Court grants petitioner’s Motion for Review and remands to the Chief Special Master for proceedings consistent with this Order. I. Petitioner’s Medical History and Tdap Vaccination On 24 May 2019, petitioner Allen Bickel received a tetanus-diphtheria-acellular-pertussis (“Tdap”) vaccine after suffering a dog bite. See Vaccination Rec. from Johns Hopkins Community Physicians – Fulton, Ex. 1 at 1 (“Vaccination Record”), ECF No. 13-1; Med. Recs. from John Hopkins Community Physicians, Ex. 2 at 10 (“Johns Hopkins Records”), ECF No. 13-2. At the time of vaccination, petitioner was 62 years old and, despite several chronic conditions and a recent upper respiratory infection (“URI”), petitioner appeared well and reported feeling well. See Johns Hopkins Records at 10–11; Vaccination Record at 2; see also Med. Recs. from Fast Track Urgent Care, Ex. 13 at 23–24 (“Urgent Care Records”), ECF No. 14-9 (petitioner’s urgent care visit for URI symptoms). On 17 June 2019, Mr. Bickel called his primary care provider concerned he had Lyme disease because he was experiencing neuropathy in his hands and toes, joint pain, muscle cramps, and malaise after a tick bite two weeks earlier. See Johns Hopkins Records at 13–15. On 18 June 2019, Mr. Bickel saw his nephrologist to address acute renal insufficiency and again “complain[ed] of symptoms compatible with a peripheral neuropathy.” Medical Records from Montgomery Renal Associates, Ex. 8 at 15 (“Renal Records”), ECF No. 13-10. On 20 June 2019, Mr. Bickel saw his primary care provider for a neurological exam (which showed normal results) and Lyme disease testing (which came back negative). See Johns Hopkins Records at 7, 15. One day later, petitioner went to urgent care for sharp abdominal pain and a cough. See Urgent Care Records at 26–27. On 24 June 2019, Mr. Bickel returned to his primary care provider for a blood pressure check and reported “concern[] because he [was] experiencing some headaches.” Johns Hopkins Records at 17–18. On 4 July 2019, Mr. Bickel went to an emergency room for bilateral upper and lower extremity weakness, numbness, muscle cramping, dyspnea upon exertion, and a shuffling gait. See Med. Recs. from MedStar Georgetown Univ. Hosp., Ex. 9, Volume III at 402 (“MedStar Georgetown Records Volume III”), ECF No. 14-3. Mr. Bickel reported bilateral lower extremity weakness began a month prior to the visit while upper extremity weakness began two weeks later. See id. The clinician assessing Mr. Bickel noted “the idea of Guiallain [sic] Barre was proposed by his nephrologist but this has not been confirmed.” Id. 3  Mr. Bickel was admitted to the hospital from 4 July 2019 to 7 July 2019 and underwent a neurology exam, which revealed extremity weakness and diminished reflexes. Id. at 402, 410–11. The attending neurologist’s attestation left a note to “[c]onsider GBS” and to conduct “[l]abwork for other causes of neuropathy.” Id. at 411. On 5 July 2019, an occupational therapist evaluated petitioner and noted “deficits in strength, endurance, sensation, standing balance and tolerance, and functional mobility resulting in decreased independence in [activities of daily living].” MedStar Georgetown Records Volume III at 437. On 6 July 2019, a physical therapist observed Mr. Bickel “mobilized in the room, around the unit and on the stairs with no [loss of balance]” and had “[n]o [physical therapy] needs at this time.” Id. at 442. A spinal MRI the same day showed “[d]egenerative changes caus[ing] mild bilateral foraminal stenosis at C5- C6, moderate bilateral foraminal stenosis at L4-L5, and moderate right foraminal stenosis at L5- S1.” See Med. Recs. from MedStar Georgetown Univ. Hosp., Ex. 9, Volume IV at 533–34 (“MedStar Georgetown Records Volume IV”), ECF No. 14-4. On 7 July 2019, Mr. Bickel was discharged from the hospital. See Med. Recs. from MedStar Georgetown Univ. Hosp., Ex. 9, Volume II at 324, ECF No. 14-2. Petitioner’s motor exam showed Mr. Bickel had four out of five strength or better in his extremities and was capable of independent movement but had decreased sensation and reflexes. Id. at 327. Mr. Bickel’s discharge notes also indicated his assessments did “not seem to fit GBS, as [his cerebrospinal fluid] protein [was] not elevated despite weeks from onset,” but did suggest “an acute axonal polyneuropathy/possibly ganglionopathy, given the last site of involvement was in mandible bilaterally 1 week prior to admission.” Id. at 325. Mr. Bickel was instructed to follow up with his neurologist to discuss the results of his labs and to schedule an electromyography (“EMG”) and nerve conduction study (“NCS”). See Id. at 328. Mr. Bickel’s condition upon discharge was described as “improved/stable.” Id. On 11 July 2019, Mr. Bickel followed up with his neurologist and underwent the recommended EMG and NCS testing. See Med. Recs. from MedStar Georgetown Univ. Hosp., Ex. 9 at 852–853, ECF No. 14-5. The study returned “[a]bnormal” results with “electrophysiologic evidence indicat[ing] a moderate, generalized, subacute, motor and sensory polyneuropathy with mixed axonal and acquired demyelinating features.” Id. at 853. On 15 July 2019, Mr. Bickel began outpatient physical therapy. Med. Recs. from ATI Physical Therapy, Ex. 12 at 6 (“Physical Therapy Records”), ECF No. 14-8. His initial evaluation identified several functional limitations, including ascending and descending stairs, dressing, driving, exercising, walking, transferring in and out of chairs, and standing for an extended period. See id. On 24 July 2019, at a follow-up visit with his primary care provider, Mr. Bickel reported continued loss of sensation in his extremities, and progress notes from the visit noted “[h]e was recently admitted to Georgetown hospital . . . and diagnosed with Guillan [sic] Barre Syndrome.” See Johns Hopkins Records at 21. On 4 November 2019, Mr. Bickel visited his endocrinologist, who made note of his continued neuropathy and stated Mr. Bickel “[h]ad GBS after Tetanus shot.” Med. Recs. from MedStar Medical Group Olney Pro. Park, Ex. 4 at 6, ECF No. 13-4. On 17 December 2019, Mr. Bickel’s neurologist evaluated him “for numbness/tingling and pain in hands/feet, [and] gait imbalance.” See Renal Records at 147. Despite overall 4 improvement since hospitalization, petitioner reported muscle cramping in his lower extremities, an occasional “intense burning sensation,” and a newly developed tremor in his arms and hands which began in October 2019. See id. The neurologist noted, based on Mr. Bickel’s spinal MRI and EMG/NCS results, it was possible he had axonal GBS which was inactive at the time of hospitalization. See id. at 149. The neurologist’s attestation noted “recurrence [of GBS] would not be expected,” but recommended “avoidance of vaccines [for one year] if able, from time of onset of [symptoms].” See id. On 3 January 2020, after 25 sessions, Mr. Bickel was discharged from physical therapy at his request due to his work schedule. Physical Therapy Records at 6. The physical therapy records covered evaluations from 2019 to 2020 and noted a “physician’s diagnosis of . . . Guillain-Barre Syndrome.” See id. According to the discharge summary, Mr. Bickel was “doing a lot better,” though he was still struggling with balance and pain. See id. On 22 September 2022, Mr. Bickel visited his neurologist with complaints of residual hand numbness, tremors and dexterity limitations. See Updated Med. Recs. from MedStar Georgetown Univ. Hosp. Neurology (Dec. 2019 through Sept. 2022), Ex. 30 at 9, ECF No. 34-9. At this point, Mr. Bickel’s neurologist deemed “mild GBS” “a primary consideration based on [Mr. Bickel’s] timeline of symptoms.” Id. at 10. Though there was overall improvement in his condition, Mr. Bickel continued to report similar symptoms in both 2023 and 2024. See Additional Updated Med. Recs. from MedStar Georgetown Univ. Hosp. Neurology (Dec. 2022 through Mar. 2023), Ex. 31 at 2–3 (“Additional Updated Neurology Records”), ECF No. 34-10; Updated Med. Recs. from MedStar Georgetown Univ. Hosp. Neurology (May 2024), Ex. 129 at 10, 12, ECF No. 58-1. II. Procedural History Before the Special Master On 4 February 2021, Mr. Bickel filed a petition for compensation against the Secretary of Health and Human Services, alleging “[a]s a result of receiving [the Tdap] vaccination . . . [he] suffered from [GBS].” Pet. at 1, ECF No. 1. The petition was assigned to Chief Special Master Corcoran in February 2021. See Notice of Assignment, ECF No. 4; see also Activation and Reassignment Order, ECF No. 21; Notice of Reassignment, ECF No. 22; Reassignment Order, ECF No. 24. After Mr. Bickel filed medical records and a statement of completion in 2021, the parties engaged in settlement discussions before “reach[ing] an impasse” in 2022. Pet’s Mot. for Entitlement Ruling on the Rec. at 1–2, ECF No. 61. In the years to follow, petitioner filed additional medical records along with expert reports from Dr. Norman Latov and Dr. Sohail Ahmed and supporting medical literature. See Pet’s Ex. List, ECF No. 59; Medical Expert Rpt. of Dr. Norman Latov, Ex. 32 (“Latov Initial Rpt.”), ECF No. 37-1; Medical Expert Rpt. of Dr. Sohail Ahmed, Ex. 79 (“Ahmed Initial Rpt.”), ECF No. 47-1. The government filed expert reports from Dr. Brian Callaghan and Dr. You-Wen He with supporting medical literature. See Expert Rpt. of Dr. Callaghan, Ex. A (“Callaghan Initial Rpt.”), ECF No. 40-1; Expert Rpt. of Dr. He, Ex. 45 (“He Initial Rpt.”), ECF No. 45-1. Petitioner and the government filed supplemental reports from all four experts. See Suppl. Medical Expert Rpt. of Dr. Norman Latov, Ex. 59 (“Latov Suppl. Rpt.”), ECF No. 43-1; Suppl. Medical Expert Rpt. of S. Sohail Ahmed, M.D., M.B.A., Ex. 100 (“Ahmed Suppl. Rpt.”), ECF No. 55; Expert Rpt. of Dr. Callaghan, Ex. E (“Callaghan Suppl. Rpt.”) ECF No. 49; Expert Rpt. of Dr. He, Ex. F (“He Suppl. Rpt.”), ECF 5 No. 52-1. On 29 May 2025, petitioner filed a Motion for Ruling on the Record, ECF No. 61. The government filed its Response on 7 July 2025. See Gov’t’s Resp. to Pet’s Mot. for Ruling on the Rec., ECF No. 63. On 23 January 2026, the Chief Special Master determined the matter could be fairly resolved via ruling on the record and denied entitlement for petitioner. Entitlement Dec. at 1 (“SM Dec.”), ECF No. 64. III. The Special Master’s Decision Denying Entitlement The Chief Special Master denied petitioner compensation on the basis petitioner did not preponderantly establish the Tdap vaccine caused his GBS. SM Dec. at 1–2. Petitioner’s claim is a Non-Table Injury, and the Chief Special Master conducted his analysis using the three-prong Althen test. See SM Dec. at 20–21 (discussing applicable law and petitioner’s Non-Table claim). Before the analysis section of the Entitlement Decision, see id. at 27–33, the Chief Special Master extensively summarized: (1) Mr. Bickel’s medical history before and after receipt of the Tdap vaccine, see id. at 2–4; (2) the expert reports submitted by both parties, see id. at 4–16; (3) the procedural history of Mr. Bickel’s petition, see id. at 16; (4) the parties’ arguments, see id. at 16–20; (5) and applicable law, see id. at 20–27. The first three pages of the Chief Special Master analysis provide an overview of GBS and how it has been treated in prior vaccine injury claims. See id. at 27–30. The Chief Special Master devoted the final three pages of the Entitlement Decision to his analysis of Mr. Bickel’s claim, concluding Mr. Bickel failed to carry his burden of proof under the Althen test because the “existing medical science” does not satisfy the first Althen prong. See S.M. Dec. at 30–33. The Chief Special Master summarized his reason for denial with a bullet point list of common deficiencies in the causal connection theory between the Tdap vaccine and the onset of GBS. See id. at 30–31 (citations omitted). The Chief Special Master then acknowledged Mr. Bickel’s petition involved “a slightly different set of experts” from prior cases, but stated the record revealed nothing new to better support causation than in prior cases. See id. at 32. The Chief Special Master briefly referenced petitioner’s expert’s presentation of Basic Local Alignment Search Tool (“BLAST”) peptide sequence search results, but stated a search result returning sequence homologies is insufficient on its own to support a theory of molecular mimicry. See id. The Chief Special Master declined to evaluate the expert reports further in his analysis and, drawing on his prior experience, found Mr. Bickel’s claim lacked preponderant support necessary for satisfying Althen prong one. See id. at 30–33. IV. The Parties’ Expert Reports A. Petitioner’s Expert Reports from Dr. Norman Latov Dr. Norman Latov, a neurologist, presented two expert reports for petitioner. Curriculum Vitae of Dr. Norman Latov, Ex. 33, ECF No. 37-2; Latov Initial Rpt.; Latov Suppl. Rpt. In his first report, Dr. Latov proffered two possible mechanisms by which “[v]accines can induce autoimmune disease, including neuropathy or GBS and its variants:” (1) molecular mimicry; and (2) bystander activation. See Latov Initial Rpt. at 4. According to Dr. Latov, molecular mimicry “occurs when there is a structural homology, in sequence or conformation, between an exogenous agent, such as a vaccine or infection, and a self or autoantigen that is subsequently 6 targeted by the immune response.” Id. at 5. The “immune reactivity against the foreign agent results in cross reactivity with the self-antigen, with subsequent tissue damage and autoimmune disease.” Id. Bystander activation, Dr. Latov explained, occurs when “infection, medications, or immunization . . . stimulate the immune system to overcome immune tolerance, allowing activation of the autoreactive cells, resulting in autoimmune disease.” Id. Dr. Latov opined because “[v]accination is a recognized trigger of GBS, and [Mr. Bickel] first developed GBS at approximately 3 weeks following administration of the vaccine, within the elevated risk period[,] [i]t is more likely than not that he had the Guillain-Barre syndrome that was triggered by the Tdap vaccine.” Id. at 6. Dr. Latov concluded his first report with a paragraph explaining why Mr. Bickel’s medical history would be inconsistent with “non-vaccine potential causes.” See id. at 7. In his second report, Dr. Latov provided supplemental explanations of molecular mimicry and bystander activation as specifically applied to Tdap and GBS in view of case reports and Institute of Medicine publications. See generally Latov Suppl. Rpt. B. Petitioner’s Expert Reports from Dr. Sohail Ahmed Dr. Sohail Ahmed is a practicing clinician in immunology and an academic investigator, who presented two reports on immunological causation for petitioner. Curriculum Vitae of Dr. Sohail Ahmed, Ex. 80, ECF No. 47-2; Ahmed Initial Rpt.; Ahmed Suppl. Rpt. In his first report, Dr. Ahmed relied on a BLAST analysis and relevant publications to establish cross-reactivity between Tdap-induced antibodies and neuronal membrane proteins associated with GBS to support Mr. Bickel’s causal theories. Ahmed Initial Rpt. at 1. Dr. Ahmed’s BLAST search results “demonstrated a high level of mimicry between 12-16-mer protein sequences contained in the BOOSTRIX (aluminum-adjuvanted) Tdap vaccine and human neuronal membrane proteins involved in GBS pathogenesis[, with] ‘[i]dentical matches’ approaching 54%.” Id. at 5; see also Ahmed Suppl. Rpt. at 23 (citing Gerald P. Linette et al., Cardiovascular Toxicity and Titin Cross-reactivity of Affinity-enhanced T Cells in Myeloma and Melanoma, BLOOD (8 Aug. 2013), Ex. 123, ECF No. 55-24; Brian J. Cameron et al., Idenfication of a Titin-derived HLA-A1-presented Peptide as a Cross-reactive Target for Engineered MAGE A3-directed T Cells, SCI. TRANSL. MED. (7 Aug. 2013), Ex. 124, ECF No. 55-25, in which 55.6% identical peptide strings were used to explain how melanoma and multiple myeloma clinical trial treatments caused the death of two patients). Dr. Ahmed also discussed two publications “mapping the ‘antigenic epitopes’ of the tetanus toxoid (TT) and diphtheria toxoid (DT) proteins,” the results of which Dr. Ahmed asserts corroborate his findings of cross-reactivity. See id. at 8 (citing R. da Silva Antunes et al., Definition of Human Epitopes Recognized in Tetanus Toxoid and Development of an Assay Strategy to Detect Ex Vivo Tetanus CD4+ T Cell Responses, PLOS ONE (Jan. 12, 2017), Ex. 88, ECF No. 47-10; B. Diethelm-Okita et al., Universal Epitopes for Human CD4+ Cells on Tetanus and Diphtheria Toxins, 181 J. INFECT. DIS. 1001, 1002 (2000), Ex. 89, ECF No. 47-11 (finding peptide sequences on tetanus and diphtheria toxoids similar to human proteins). Dr. Ahmed also provided detailed responses to government’s expert reports to rebut their criticisms of Dr. Latov’s expert reports. See id. at 9– 30. Dr. Ahmed’s supplemental report reiterated the opinions expressed in his first report and provided extensive responses to the government’s expert reports. See Ahmed Suppl Rpt. Dr. Ahmed concluded, “to a reasonable degree of medical and scientific certainty regarding the medical history, laboratory tests provided, and the BLAST analysis, . . . Mr. Bickel more likely 7 than not developed GBS from receipt of the aluminum-adjuvanted BOOSTRIX Tdap vaccine.” Ahmed Initial Rpt. at 31. C. The Government’s Expert Reports from Dr. Brian Callaghan Dr. Brian Callaghan, a neurologist, prepared two reports for the government. See Dr. Callaghan CV, Ex. B, ECF No. 40-8; Callaghan Initial Rpt.; Callaghan Suppl. Rpt. In his first report, Dr. Callaghan disputed Dr. Latov’s general causation theory, stating “[a]fter an extensive literature review, I was unable to find biologic evidence linking the Tdap vaccine with GBS.” Callaghan Initial Rpt. at 6. Additionally, Dr. Callaghan criticizes Dr. Latov’s reliance on case reports, noting “a proximate temporal relationship alone is insufficient to show causation.” Id. at 5. Considering petitioner’s prior URI and “strong epidemiologic support for an association between URI and GBS,” Dr. Callaghan asserts “there is far greater evidence that supports a nonvaccine cause of GBS, than an alleged vaccine cause.” Id. at 7 (citations omitted). In Dr. Callaghan’s second report, he questioned Dr. Ahmed’s reliance on case reports, VAERS data, and a 1994 Institute of Medicine report instead of the 2012 Institute of Medicine Report. Callaghan Suppl. Rpt. at 1–2. Dr. Callaghan also critiqued Dr. Ahmed’s dismissal of the Mr. Bickel’s URI because, while Dr. Ahmed argued petitioner had a non-viral bacterial sinus infection, Dr. Callaghan argues the nature of petitioner’s URI (viral or bacterial) is unclear. Id. at 2. Dr. Callaghan concludes his second report by stating “there is evidence of a more likely nonvaccine cause, namely URI, of GBS based on multiple rigorous epidemiologic studies.” Id. D. The Government’s Expert Reports from Dr. You-Wen He Dr. You-Wen He, a professor of immunology at Duke University Medical Center and a medical doctor, prepared two reports for the government. Curriculum Vitae, You-Wen He, M.D. Ph.D., Ex. D, ECF No. 45-32; He Initial Rpt.; He Suppl. Rpt. In Dr. He’s first report, Dr. He criticized Dr. Latov’s causation theories as unsupported by reliable evidence. He Initial Rpt. at 15. Dr. He challenged the “old theory” of molecular mimicry in part on the basis “[m]ere sequence similarity cannot be used to conclude that vaccines cause autoimmune diseases.” Id. at 5–6. Dr. He also disagreed with Dr. Latov’s bystander activation theory, stating “[b]ystander activation has never been shown to be a cause of autoimmune diseases.” Id. at 6. Dr. He then criticized: (1) Dr. Latov’s reliance on case reports which had been reviewed in studies finding no causal relationship between Tdap and GBS; and (2) Dr. Latov’s use of the VAERS database, considering “VAERS reporting has not been used as epidemiologic evidence in any of the authoritative systematic studies.” Id. at 11–12 (citations omitted). Dr. He proposed Mr. Bickel’s GBS was more likely caused by his URI and the contributing factor of severe obesity. See id. at 13. In his second report, Dr. He primarily responded to Dr. Ahmed’s reports and responses. Ahmed Suppl. Rpt. at 1. Dr. He criticized Dr. Ahmed’s BLAST searches as “entirely expected” considering “sequence homology between microbial pathogen and human proteins is a common phenomenon.” Id. at 2. Dr. He also asserts the studies Dr. Ahmed relies on as evidence of cross- reactivity “by no means provide evidence to support Tdap vaccination would have induced cross-reactive antibodies to neuronal membranes and cause GBS” because “[m]ere sequence homologies and identification of epitopes do not suggest any pathological roles in autoimmune disease development.” Id. at 3–4. Dr. He concludes “to a reasonable degree of medical 8 probability . . . there is no reliable evidence to support the petitioner’s experts’ theory that the Tdap vaccine caused Mr. Bickel’s GBS.” He Initial Rpt. at 15. V. Parties’ Arguments and Petitioner’s Motion for Review On 23 February 2026, petitioner moved for review of the Chief Special Master’s Entitlement Decision. See Mot. for Rev., ECF No. 68, 68-1. Petitioner contends the Chief Special Master’s “Decision was erroneous” because the Chief Special Master “fail[ed] to consider the relevant evidence of record” and “fail[ed] to set forth a rational basis for his Decision.” Id. at 5, 13. In its response, the government argues the Chief Special Master “properly considered all of the evidence in the record,” “correctly evaluated petitioner’s evidence under the applicable legal standards, and set forth a rational basis for his Decision.” Gov’t’s Resp. at 6–7, ECF No. 70. A. Petitioner’s Argument the Chief Special Master Failed to Consider Relevant Record Evidence Petitioner argues the Chief Special Master “erroneously judged this case using his analysis and conclusions of evidence from past cases instead of evaluating the individual circumstances and record evidence of this case” and failed “to address new evidence adduced by Mr. Bickel, including new and significant medical literature submitted by his experts.” Mot. for Rev. at 5. According to petitioner, “the Decision did not analyze the evidence submitted in support of Mr. Bickel’s claim” and incorrectly concluded “[p]etitioner had not filed new medical literature that would better support causation.” Id. at 7 (citing SM Dec. at 32). Petitioner claims to have filed approximately fifty new pieces of medical literature but argues there are two articles which are particularly relevant to the Althen prong one causation analysis. Id. at 7–8. According to petitioner, Exhibits 88 and 89 support petitioner’s molecular mimicry theory by identifying antigenic epitopes contained in the Tdap vaccine. See id. at 8 (citing R. da Silva Antunes et al., Definition of Human Epitopes Recognized in Tetanus Toxoid and Development of an Assay Strategy to Detect Ex Vivo Tetanus CD4+ T Cell Responses, PLOS ONE (Jan. 12, 2017), Ex. 88, ECF No. 47-10; B. Diethelm-Okita et al., Universal Epitopes for Human CD4+ Cells on Tetanus and Diphtheria Toxins, 181 J. INFECT. DIS. 1001, 1002 (2000), Ex. 89, ECF No. 47-11). Petitioner further contends the Chief Special Master failed to conduct a careful review of the record because the Decision did not adequately review petitioner’s BLAST research. See Mot. for Rev. at 10–12. The government contends “[t]he Decision makes clear that the Chief Special Master considered the entire record in this case[.]” Gov’t’s Resp. at 6. In support of the government’s argument, the government notes special masters are presumed to have considered the relevant record evidence, and this presumption is only overcome when a special master “affirmatively indicates he did not consider a piece of evidence.” Id. at 6–7. Further, the government states “[s]pecial masters are not required to discuss every piece of evidence in a decision, so long as they address the parties’ positions and arguments.” Id. at 9 (citations omitted). The government also challenges petitioner’s argument the Chief Special Master failed to adequately analyze Exhibits 88 and 89. Id. at 9. Though petitioner asserts the importance of these studies to their case, the government notes “[neither of the studies] were referenced or cited in petitioner’s 9 Motion for Ruling on the Record.” Id. In the government’s view, if the studies were critical to petitioner’s causation analysis, petitioner would have included them in the Motion for Ruling on the Record. See id. at 9–10. Further, the government argues it is “impractical for the Chief Special Master to endeavor to discuss every single item in his Decision[,]” id. at 7, and further characterizes petitioner’s position as a “post hoc rationalization in seeking grounds for review,” id. at 10. The government also contends the Chief Special Master “sufficiently discussed” petitioner’s BLAST search results in his Decision. See Gov’t’s Resp. at 10. The government notes the Chief Special Master generally critiqued petitioner’s molecular mimicry theory by emphasizing the “limited evidentiary value to homology showings.” Id. at 11 (quoting SM Dec. at 32). The government argues the Chief Special Master described petitioner’s argument as “the same molecular mimicry theory as in previous cases” and “demonstrate[d] that he analyzed both petitioner’s molecular mimicry theory concerning homology, and also the many weaknesses of that theory as articulated by respondent’s experts.” See id. B. Petitioner’s Argument the Chief Special Master Failed to Set Forth a Rational Basis for the Decision Petitioner argues the Chief Special Master failed to set forth a rational basis for his Decision by “shortcut[ting] an evaluation and analysis of the evidence presented in this case by instead listing out the rulings [he] has made in previous cases and pronouncing them equally applicable here.” See Mot. for Rev. at 13. Petitioner states causation is to be evaluated based on evidence presented in each case, and a Decision must set forth its findings with specificity. See id. at 5, 15 (citations omitted). Petitioner claims the bullet points do not reflect the Decision’s review of the record and “impede[] this Court’s ability to review the Decision, warranting reversal.” Id. at 13. Instead of analyzing petitioner’s particular causation theory, petitioner states the Chief Special Master “relied on a bullet point list summarizing the purported deficiencies in any claim that the Tdap vaccine can cause GBS.” Id. at 14 (citing SM Dec. at 28, 31). Petitioner describes the bulleted list as a “cheat sheet” listing its points in a conclusory fashion without a reasoned explanation. See id. Petitioner argues a decision must reflect a careful review of the record and “[n]either conclusory statements nor citation to unsupportive cases provide adequate support for a legal conclusion or factual finding.” Id. at 15 (citations omitted). Additionally, petitioner contends the cases the Chief Special Master cites as general support for the bullet point list lack legal reasoning, see id. at 15–16, and any bulleted items which have legal backing are “based on evidence found in those cases and not in the present case,” id. at 18. The government contends the Chief Special Master appropriately relied on his “substantial prior experience with similar cases involving the same vaccine and injury compensation.” Gov’t’s Resp. at 7–8. The government argues “[i]t is well settled that special masters may rely on previous cases in articulating a rational basis for their decision.” Id. at 8 (citations omitted). Additionally, the government maintains it is important for special masters to utilize their body of knowledge and accumulated expertise when deciding vaccine cases. See id. According to the government, the Chief Special Master used cases similar to the present case to highlight the recognized weaknesses of petitioner’s molecular mimicry theory. See id. at 12. The government contends using previous cases to deny compensation in this case is not erroneous, because the causal theory common to all the cases was itself categorically 10 insufficient. Id. The government states “the Chief Special Master appropriately applied his prior case law as part of the basis for his decision” and it “was well within the Chief Special Master’s discretion” to do so. Id. at 9, 13. VI. Legal Standard A. The Court’s Standard of Review of a Special Master’s Decision The National Childhood Vaccine-Injury Compensation Act entrusts this court with reviewing a Special Master’s decision upon timely motion of either party. See 42 U.S.C. § 300aa-12(e)(1)–(2). In reviewing the record of the proceedings before the Special Master, the Court may: (1) “uphold the findings of fact and conclusions of law of the special master and sustain the special master’s decision;” (2) “set aside any findings of fact or conclusion 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 (3) “remand the petition to the special master for further action in accordance with the court’s direction.” Id. § 300aa-12(e)(2). “Fact findings are reviewed . . . 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.” Saunders v. Sec’y of Health & Hum. Servs., 25 F.3d 1031, 1033 (Fed. Cir. 1994) (quoting Munn v. Sec’y of Health & Hum. Servs., 970 F.2d 863, 870 n.10 (Fed. Cir. 1992)). In reviewing a special master’s decision, a court does 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[—t]hese are all matters within the purview of the fact finder.” Lampe v. Sec’y of Health & Hum. Servs., 219 F.3d 1357, 1360 (Fed. Cir. 2000) (quoting Munn, 970 F.2d at 871). “Reversal is appropriate only when the special master’s decision is arbitrary, capricious, an abuse of discretion, or not in accordance with the law.” Snyder v. Sec’y of Health & Hum. Servs., 88 Fed. Cl. 706, 718 (2009). The arbitrary and capricious standard “is a highly deferential standard of review:” “[i]f 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.” Hines v. Sec’y of Health & Hum. Servs., 940 F.2d 1518, 1528 (Fed. Cir. 1991). B. The Standard of Causation in Vaccine Cases “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.” Broekelschen v. Sec’y of Health & Hum. Servs., 618 F.3d 1339, 1341 (Fed. Cir. 2010) (citing 42 U.S.C. §§ 300aa-11(c)(1), -13(a)(1)). “A petitioner can show causation under the Vaccine Act in one of two ways”: (1) “by showing that she sustained an injury in association with a vaccine listed in the Vaccine Injury Table,” in which case “causation is presumed”; or (2) “if the complained-of injury is not listed in the Vaccine Injury Table . . . the petitioner may seek compensation by proving causation in fact.” Id. at 1341–42 (internal citations omitted). Vaccine cases employ a burden shifting standard: “[o]nce the petitioner has demonstrated causation, she is entitled to compensation unless the government can show by a preponderance of the evidence 11 that the injury is due to factors unrelated to the vaccine.” Id. at 1342 (citing Doe v. Sec’y of Health & Hum. Servs., 601 F.3d