Eberline v. Secretary of Health and Human Services

IN THE UNITED STATES COURT OF FEDERAL CLAIMS ______________________________________ ) DOUGLAS EBERLINE, ) ) Petitioner, ) No. 23-655 ) v. ) Filed: May 29, 2026 ) SECRETARY OF HEALTH AND ) Re-issued: June 15, 2026 ∗ HUMAN SERVICES, ) ) Respondent. ) ______________________________________ ) OPINION AND ORDER Petitioner Douglas Eberline (“Petitioner”) seeks review of the Chief Special Master’s decision denying compensation under the National Vaccine Injury Compensation Program, 42 U.S.C. § 300aa-10, et seq. (“Vaccine Act”). Petitioner alleges that he suffered from polymyalgia rheumatica (“PMR”) after receiving a pneumococcal vaccine on August 19, 2020, and an influenza vaccine on September 12, 2020. The Chief Special Master denied compensation on the basis that Petitioner failed to establish by a preponderance of the evidence that these vaccines can cause PMR. In accordance with Rules 23 and 24 of the Vaccine Rules of the United States Court of Federal Claims (“Vaccine Rules”), Petitioner filed a Motion for Review in this Court, arguing that the Chief Special Master abused his discretion by refusing to consider Petitioner’s supplemental evidence and erred in denying compensation. For the reasons explained below, the Court DENIES Petitioner’s Motion. ∗ The Court issued this Opinion and Order under seal on May 29, 2026, and directed the parties to file any proposed redactions, pursuant to Vaccine Rule 18(b), by June 12, 2026. As the parties did not propose any redactions, the Court reissues the Opinion and Order publicly in full. See Vaccine Rule 18(d).  I. BACKGROUND A. Petitioner’s Medical History, Vaccination, and Symptoms On August 19, 2020, Petitioner received a pneumococcal vaccine. Pet’r’s Ex. 6 at 1, ECF No. 6-6; Pet’r’s Ex. 4 at 9, ECF No. 6-4. Approximately three weeks later, on September 12, 2020, Petitioner was immunized with the influenza vaccine as well. 1 Pet’r’s Ex. 1 at 2, ECF No. 6-1. Prior to receiving these vaccines, Petitioner’s medical records included a history of carpal tunnel syndrome, 2 and osteoarthritis 3 in his right knee. See, e.g., ECF No. 6-4 at 25 (reporting Petitioner’s history of carpal tunnel syndrome dating to 2004); Pet’r’s Ex. 5 at 73–75, ECF No. 6-5 (reporting Petitioner’s December 14, 2016 diagnosis of osteoarthritis in the right knee). Petitioner first complained of symptoms following these vaccinations on October 9, 2020, when Petitioner saw orthopedist Vimala Ramachandran, M.D. Pet’r’s Ex. 3 at 15, ECF No. 6-3. Petitioner described “constant numbness, tingling, and burning sensations in his bilateral hands,” and noted that the pain had been present “for about a month.” Id. Dr. Ramachandran’s reported assessment was “[b]ilateral carpal tunnel syndrome,” which Dr. Ramachandran planned to treat by 1 The vaccinations were separated by 24 days but both parties’ experts, and the Chief Special Master, at times refer to this period as approximately one month. See Pet’r’s Ex. 26 at 12, ECF No. 19-1 (Petitioner’s expert stating that the vaccinations were separated by “one month”); Resp’t’s Ex. A at 5, ECF No. 18-1 (Respondent’s expert describing the vaccinations as separated by “a month”); Entitlement Dec. at 2, ECF No. 28 (Chief Special Master referring to the period as “almost one-month”). Whether this interval is most accurately characterized as 24 days, three weeks, or one month is immaterial to the parties’ arguments. 2 Carpal tunnel syndrome is “an entrapment neuropathy characterized by pain and burning or tingling paresthesias in the fingers and hand, sometimes extending to the elbow. Symptoms result from compression of the median nerve in the carpal tunnel.” Dorland’s Illustrated Medical Dictionary 1794 (33d ed. 2020). 3 Osteoarthritis is “a noninflammatory degenerative joint disease seen mainly in older persons, characterized by degeneration of the articular cartilage, hypertrophy of bone at the margins, and changes in the synovial membrane. It is accompanied by pain, usually after prolonged activity, and stiffness, particularly in the morning or with inactivity.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 1326. 2 ordering an electromyography (“EMG”) test, 4 providing Petitioner with wrist braces to wear at night, and instructing him to apply heat and ice in addition to over-the-counter medication to alleviate the pain. Id. at 16. One week later, on October 16, 2020, Petitioner reported joint stiffness—especially in his fingers, but also in his hips, knees, shoulders, wrists, and hands—to his primary care provider, Michaela M. Skelly, M.D. ECF No. 6-4 at 30. Petitioner felt that this pain had worsened after he received the pneumococcal and influenza vaccines. Id. Dr. Skelly assessed that the pain may be due to Petitioner’s carpal tunnel syndrome but also recorded unspecified joint and hand pain. Id. at 33–34. Based on this assessment, Dr. Skelly prescribed prednisone 5 and ordered x-rays and lab tests to “check[] for inflammation and rheumatoid arthritis and other autoimmune conditions.” Id. The lab results indicated that Petitioner’s erythrocyte sedimentation rate (“ESR”) 6 and C-reactive protein (“CRP”) 7 levels were somewhat elevated. Id. at 170; Pet’r’s Ex. 2 at 13, ECF No. 6-2. Based on the results of the lab tests, on November 3, 2020, Petitioner saw rheumatologist Physician’s Assistant (“PA”) Rachel Herrin. See ECF No. 6-2 at 10–14. After reviewing Petitioner’s lab results and performing a physical exam, id. at 10–13, PA Herrin discussed with 4 EMG is “an electrodiagnostic technique for recording the extracellular activity . . . of skeletal muscles at rest, during voluntary contractions, and during electrical stimulation.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 595. 5 Prednisone is “a synthetic glucocorticoid derived from cortisone, administered orally as an anti[-]inflammatory and immunosuppressant in a wide variety of disorders.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 1486. 6 ESR is “the rate at which erythrocytes precipitate out from a well-mixed specimen of venous blood.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 1569. Elevated ESR may reflect, among other things, “inflammatory disease.” Id. 7 CRP is “a globulin that forms a precipitate with the somatic C-polysaccharide of the pneumococcus in vitro; it is the most predominant of the acute-phase proteins.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 1509. 3 Petitioner “possible causes of [Petitioner’s] pain,” including “inflammatory arthritis, PMR, [or] reactive arthritis,” id. at 14. PA Herrin also noted that Petitioner’s “body may have just been reacting to having 2 shots done within a short period of time.” Id. PA Herrin ordered repeat lab tests and instructed Petitioner to continue with injections through his orthopedist. Id. The results of Petitioner’s EMG test were “compatible with [] mild carpal tunnel syndrome” and “non[- ]localized ulnar [] neuropathy[] across the elbow,” on the left side. Pet’r’s Ex. 11 at 3, ECF No. 7-2. On reviewing Petitioner’s repeat lab results, PA Herrin observed that Petitioner’s CRP levels remained elevated and prescribed more prednisone on November 13, 2020. ECF No. 6-2 at 15. Petitioner visited PA Herrin for a follow-up appointment on December 21, 2020, reporting that “[t]he prednisone ha[d] helped a lot with his joint pains” and “[h]is joints [were] feeling great.” Id. at 16. Upon examining Petitioner, PA Herrin observed generalized joint stiffness and muscle aches. Id. PA Herrin recorded that she was “[s]till leaning more toward PMR or reactive arthritis” as the likely cause of Petitioner’s pain “given all [Petitioner’s] recent vaccines, shots, etc[.],” and continued to prescribe prednisone, ordered repeat lab tests, and scheduled a follow-up visit for the following month. Id. at 20. Petitioner’s next visit occurred on January 12, 2021, when Petitioner saw Vijayabhanu Mahadevan, M.D., the doctor who had concurred with PA Herrin’s treatment plans during previous visits. See id. at 14, 20–21. At that appointment, Plaintiff reported minimal stiffness but no joint pain or swelling. Id. at 21. Dr. Mahadevan noted that Petitioner’s most recent lab results were normal, and she was “[s]till leaning more toward PMR” as a possible cause of Petitioner’s pain, “even though symptom onset was after flu/pneumonia vaccination.” Id. at 24. Dr. Mahadevan recommended Petitioner begin reducing his prednisone given his lack of symptoms and normal lab results. Id. 4  Petitioner visited PA Herrin three additional times between March and June 2021, reporting improved symptoms while tapering his prednisone. See id. at 25 (reporting on March 11, 2021, that Petitioner was “feeling much back to his normal self and [was] hoping to work on getting off of prednisone”); id. at 30 (reporting on May 5, 2021, that Petitioner experienced “[n]o major flaring of PMR symptoms [while] going from 5 mg to 4 mg” of prednisone); id. at 35 (reporting on June 30, 2021, that Petitioner felt “pretty well” after further reducing his prednisone dosage). Petitioner stopped taking prednisone by August 2021. Pet’r’s Ex. 7 at 9, ECF No. 6-7. Petitioner saw his orthopedist, Dr. Ramachandran, on July 23, 2021, reporting that “the numbness and tingling ha[d] worsened in his hands.” ECF No. 6-3 at 11. At that appointment, Petitioner decided he would like to proceed with surgery to alleviate his carpal tunnel symptoms. Id. at 12. Dr. Ramachandran performed a carpal tunnel release procedure on Petitioner’s right side on August 5, 2021. Id. at 23–24. Dr. Ramachandran performed a carpal tunnel release procedure on Petitioner’s left side on November 4, 2021. See Pet’r’s Ex. 12 at 30–31, ECF No. 7-3. The following spring, Petitioner continued to report stable conditions and maintained normal lab results at follow-up visits with his rheumatologist, Dr. Mahadevan. See ECF No. 6-7 at 16–25 (describing visits in February and May 2022). B. Procedural History Petitioner filed his petition for compensation on May 4, 2023. See Pet. for Comp., ECF No. 1. He requested compensation under the Vaccine Act for PMR symptoms allegedly caused by either a pneumococcal vaccine, an influenza vaccine, or both vaccines together. See id. ¶¶ 4, 11, 19. The Vaccine Act establishes a no-fault system whereby individuals who are injured by covered vaccines may receive compensation. See generally 42 U.S.C. § 300aa-10(a). The Vaccine Act’s Injury Table (“Table”) outlines conditions with known links to covered vaccines, along with a time period for the expected manifestation of each condition. Id. § 300aa-14. A petitioner may 5 presumptively establish entitlement to compensation by showing that he sustained or significantly aggravated a Table condition within the period for manifestation or aggravation provided in the Table. Id. § 300aa-11(c)(1)(C)(i). If, however, the petitioner’s condition does not meet the Table’s requirements (i.e., either the condition is not listed or the manifestation or significant aggravation occurred outside of the time period listed), the petitioner must establish that the covered vaccine caused the injury in order to recover. Id. § 300aa-11(c)(1)(C)(ii). Petitioner asserts that the influenza and pneumococcal vaccines actually caused or significantly aggravated Petitioner’s PMR, which is not a Table condition. See ECF No. 1 ¶¶ 4, 11, 19. Given that Petitioner could not rely on the Table’s presumption, the parties spent several months gathering evidence and expert reports. Each party retained one expert. 1. Expert Reports a. Petitioner’s Expert Report Petitioner’s expert, Petros Efthimiou, M.D., a Fellow of the American College of Rheumatology who has researched inflammatory rheumatic conditions (including PMR) for 24 years, opines that Petitioner’s receipt of the influenza vaccine on September 12, 2020 “more likely than not was a substantial factor contributing to the onset of clinical [PMR].” Pet’r’s Ex. 16 at 1– 2, ECF No. 16-2; see also Pet’r’s Ex. 17, ECF No. 16-3 (Dr. Efthimiou’s curriculum vitae). Petitioner filed Dr. Efthimiou’s initial report on May 20, 2024, in which Dr. Efthimiou concludes that Petitioner’s medical records establish that he suffered from PMR. Id. at 3–10. Dr. Efthimiou describes PMR as “a condition characterized by inflammatory pain and stiffness in the shoulder and in the pelvic girdle and neck.” Id. at 10. Dr. Efthimiou further explains that PMR “occurs in people over the age of 50, and is associated with an acute-phase response, a rapid response to low doses of glucocorticoids [], and a generally favorable prognosis.” Id. He goes on to explain that PMR is currently understood to be “an immune-mediated disease that includes the interaction of 6 multiple factors, both genetic and environmental.” Id. (citing Pet’r’s Ex. 18, Dario Camellino et al., Pathogenesis, Diagnosis and Management of Polymyalgia Rheumatica, 36 Drugs & Aging 1015 (2019), ECF No. 16-4). As support for his conclusion that Petitioner’s receipt of the influenza vaccine likely contributed to his PMR, Dr. Efthimiou relies on various pieces of medical and scientific literature documenting instances of PMR where vaccines may have been an environmental trigger. See id. For example, Dr. Efthimiou cites a case series that discussed “multiple cases” of PMR or giant cell arteritis (“GCA”) associated with influenza vaccination. Id. (citing Pet’r’s Ex. 19, A. Soriano et al., Giant Cell Arteritis and Polymyalgia Rheumatica After Influenza Vaccination: Report of 10 Cases and Review of the Literature, 21 Lupus 153 (2012), ECF No. 16-5). Dr. Efthimiou notes that the case series included a table of literature that similarly found cases of PMR associated with the receipt of the influenza and tetanus vaccines. Id. (citing ECF No. 16-5 at 3 tbl. 2). Dr. Efthimiou also cites another case series that discussed “10 patients with GCA associated with [influenza] vaccine administration” and two “cases reporting symptoms of classical PMR after vaccination.” Id. at 10–11 (citing Pet’r’s Ex. 20, Eric Liozon et al., Giant Cell Arteritis or Polymyalgia Rheumatica After Influenza Vaccination: A Study of 12 Patients and a Literature Review, 20 Autoimmunity Revs. 102732 (2021), ECF No. 16-6). In addition to these case reports and literature reviews, Dr. Efthimiou explains how the current pathological understanding of PMR supports the possibility that multiple vaccines are associated with the onset of PMR. Id. at 11. The medical community’s current understanding of “inflammatory rheumatic diseases,” Dr. Efthimiou opines, is a “spectrum between autoinflammatory diseases [] and autoimmune diseases [].” Id. at 11 (citing Pet’r’s Ex. 22, Elvis Hysa et al., Immune System Activation in Polymyalgia Rheumatica: Which Balance Between 7 Autoinflammation and Autoimmunity? A Systemic Review, 21 Autoimmunity Revs. 102995 (2022), ECF No. 16-8). Thus, Dr. Efthimiou postulates that some diseases are “linked to being triggered by the innate immune response, whereas others are linked to being characterized by a dysregulated adaptive immune response.” Id. Next, Dr. Efthimiou explains how this understanding of PMR’s pathogenesis supports his theory, describing how “PMR mechanistically arises due to the disruption of self-tolerance by specific types of T cells and the inability of T regulatory cells to prevent autoreactivity.” 8 Id. at 11–12. In other words, “[t]he antigenic responses to the vaccine proteins contained in a vaccine could initiate autoreactive T cells that attack the body by providing either specifically or nonspecifically the necessary immune signals to ultimately dysregulate (i.e., lose self-tolerance) and activate the required autoreactive immune cells necessary for clinical disease expression.” Id. at 12. Dr. Efthimiou hypothesizes that “[t]hese autoreactive cells” may have already been present in Petitioner due to previously administered vaccines or other environmental factors. Id. Finally, Dr. Efthimiou explains how his theory that the influenza vaccine can cause PMR applies in Petitioner’s case, based largely on the type of vaccines that Petitioner received as well as the timing of receipt. See id. at 13–17. In Dr. Efthimiou’s medical opinion, because Petitioner had received the pneumococcal vaccine a few weeks prior to his influenza vaccine, Petitioner’s immune system would have been “providing a ‘peak’ immune response” at the time he received the influenza vaccine. Id. at 13. As support for this opinion, Dr. Efthimiou cites a study analyzing participants’ innate immune responses to influenza and pneumococcal vaccinations, finding that both “are potent activators of the innate immune system.” Id. at 14 (citing Pet’r’s Ex. 25, Gerlinde 8 T cells are “responsible for . . . cellular immunity.” Dorland’s Illustrated Medical Dictionary, supra note 2, at 1070. 8 Obermoser et al., Systems Scale Interactive Exploration Reveals Quantitative and Qualitative Differences in Response to Influenza and Pneumococcal Vaccines, 38 Immunity 831 (2013), ECF No. 16-11). Dr. Efthimiou notes that because both “vaccines are known to elicit B-cell responses in a T-cell dependent manner” Petitioner’s receipt of the two vaccines within a few weeks of one another had the potential to “adversely trigger[] cross-reactive immune memory cells.” Id. at 15. In Dr. Efthimiou’s opinion, therefore, Petitioner’s “systemic autoimmune reaction, demonstrated by the development of [PMR], was likely triggered by the influenza vaccination he received in 2020.” Id. at 16. b. Respondent’s Expert Report Respondent submitted an expert report from rheumatologist Maxime Kinet, M.D., Ph.D., who has evaluated and treated approximately three dozen individuals with PMR throughout his career and has published several peer-reviewed journal articles. See Resp’t’s Ex. A at 1, ECF No. 18-1; see also Resp’t’s Ex. B, ECF No. 18-11 (Dr. Kinet’s curriculum vitae). In his report, Dr. Kinet concludes that “Dr. Efthimiou does not provide any reliable support for how influenza vaccination might have contributed to or caused [Petitioner’s] symptoms” and therefore “there is no preponderance of evidence to support such [] causation.” Id. at 6. At the outset of his report, Dr. Kinet explains that PMR “is a systemic inflammatory disorder of unclear etiopathogenesis affecting persons over fifty years old.” Id. at 4 (citing Resp’t’s Ex. A, Tab 1, Tanaz A. Kermani & Kenneth J. Warrington, Polymyalgia Rheumatica, 381 Lancet 63 (2013), ECF No. 18-2; and Resp’t’s Ex. A, Tab 2, Bhaskar Dasgupta et al., 2012 Provisional Classification Criteria for Polymyalgia Rheumatica: A European League Against Rheumatism/American College of Rheumatology Collaborative Initiative, 71 Annals Rheumatic Diseases 484 (2012), ECF No. 18-3). Dr. Kinet notes that PMR patients typically “present with bilateral pain and stiffness in the neck, shoulders, upper arms, hips, and thighs.” Id. (citing ECF 9 No. 18-2; ECF No. 18-3; and Resp’t’s Ex. A, Tab 3, Carlo Salvarani et al., Polymyalgia Rheumatica and Giant-Cell Arteritis, 347 NEJM 261 (2002), ECF No. 18-4). In greater than 98% of PMR cases, Dr. Kinet observes, “[i]nflammatory markers, such as ESR or CRP, are elevated.” Id. (citing Resp’t’s Ex. A, Tab 5, Fabrizio Cantini et al., Erythrocyte Sedimentation Rate and C- Reactive Protein in the Evaluation of Disease Activity and Severity in Polymyalgia Rheumatica: A Prospective Follow-Up Study, 30 Seminars in Arthritis & Rheumatism 17 (2000), ECF No. 18- 6; and Resp’t’s Ex. A, Tab 6, Carlo Salvarani et al., Acute-Phase Reactants and the Risk of Relapse/Recurrence in Polymyalgia Rheumatica: A Prospective Followup Study, 53 Arthritis & Rheumatism 33 (2005), ECF No. 18-7). Like Dr. Efthimiou, Dr. Kinet explains that in most cases of PMR, symptoms “improve promptly . . . with moderate doses of glucocorticoids.” Id. (citing ECF No. 18-2). In discussing whether Petitioner’s clinical presentation was consistent with PMR, Dr. Kinet concedes that Petitioner “may have suffered from PMR,” but observes that “the distal predominance of his symptoms is somewhat unusual, as is the persistence of high inflammatory markers well after resolution of symptoms.” Id. Dr. Kinet next turns to Dr. Efthimiou’s causal theory, which Dr. Kinet concludes is unsupported by the medical and scientific evidence. Id. at 4–6. Dr. Kinet explains that “PMR and influenza vaccinations are both exceedingly common occurrences.” Id. at 4. Specifically, Dr. Kinet notes that the estimated lifetime risk of PMR for men is around two percent, id. (citing Resp’t’s Ex. A, Tab 7, Cynthia S. Crowson et al., The Lifetime Risk of Adult-Onset Rheumatoid Arthritis and Other Inflammatory Autoimmune Rheumatic Diseases, 63 Arthritis & Rheumatism 633 (2011), ECF No. 18-8), and over half of the adult population received the influenza vaccination during the 2019–2020 influenza season, id. (citing Resp’t’s Ex. A, Tab 8, Ctrs. for Disease Control & Prevention, Flu Vaccination Coverage, United States, 2019–20 Influenza Season, 10 https://www.cdc.gov/flu/fluvaxview/coverage-1920estimates.htm (2020), ECF No. 18-9). Dr. Kinet thus concludes that “chance association between these two very common events is likely.” Id. And the studies Dr. Efthimiou cites “consist[] almost entirely of case reports and small case series of 20 patients or less, which are not sufficient to establish causation in the case of two common events.” Id. Dr. Kinet then explains that to “establish[] causation between a vaccine and a disease” medical experts “require that the natural infection against which the vaccine protects, being generally a stronger immune stimulus, should also cause the proposed disease.” Id. (citing Resp’t’s Ex. A, Tab 9, Ami Schattner, Consequence or Coincidence? The Occurrence, Pathogenesis and Significance of Autoimmune Manifestations After Viral Vaccines, 23 Vaccine 3876 (2005), ECF No. 18-10). Dr. Kinet observes, however, that “leading PMR experts have published in top medical journals that a viral or other infectious cause [of] PMR has never been substantiated.” Id. (citing ECF No. 18-2; ECF No. 18-4). Thus, Dr. Kinet opines that Dr. Efthimiou fails to provide reliable evidence that either the influenza vaccine, the pneumococcal vaccine, or their targeted pathogens can cause PMR. Id. at 5. Turning to Dr. Efthimiou’s purported pathogenic explanation of causation, Dr. Kinet concedes that Dr. Efthimiou’s discussion of the “interplay between innate and adaptive arms of the immune system” and “environmental and other genetic factors” of pathogenesis is a “very well known” and “general concept of pathogenesis for autoimmune disorders.” Id. at 5 (citing ECF No. 16-2 at 10–12). But, in Dr. Kinet’s medical and scientific opinion, such a general concept fails to “provide specific evidence for how influenza and/or pneumococcal vaccination might lead to PMR.” Id. Dr. Kinet explains that Dr. Efthimiou’s report fails to “provide any biological mechanistic theory,” id., for how “antigenic responses to the vaccine proteins” could “initiate 11 autoreactive T cells that attack the body” leading to dysregulation and ultimately activating the immune cells necessary for expression of PMR, id. (quoting ECF No. 16-2 at 12). Dr. Kinet therefore concludes that “Dr. Efthimiou does not provide a specific and credible medical scientific theory for how vaccines might lead to PMR.” Id. Dr. Kinet also acknowledges that Petitioner may have possessed “a predisposition to PMR, if one grants that his reportedly similar episode of joint pain in 2010 or 2011 was PMR.” Id. Yet, Dr. Kinet notes that Petitioner received “many vaccinations, including several closely spaced ones,” over the intervening years without developing PMR. Id. Thus, “it is not clear why these closely spaced vaccinations, or any of [Petitioner’s] other recent vaccinations, did not lead to PMR.” Id. Next, Dr. Kinet responds to Dr. Efthimiou’s argument that the period of approximately three weeks between Petitioner’s vaccinations increased Petitioner’s immune response to the influenza vaccine. Id. (citing ECF No. 16-2 at 13). Dr. Kinet opines that Dr. Efthimiou’s argument is unsupported by the cited study, which found that the “innate immune activation elicited by both [the pneumococcal and influenza] vaccines . . . peak[s] within hours to a few days.” Id. at 5–6 (emphasis in original) (citing ECF No. 16-11). Thus, it is “not clear how vaccines separated by a month could produce this putative boosting phenomenon.” Id. at 6. Dr. Kinet finds that Dr. Efthimiou’s report “provides no reliable medical or scientific evidence for how [the] influenza vaccination alone or [the] two different vaccines spaced by a month would lead to PMR.” Id. Finally, Dr. Kinet opines that Dr. Efthimiou “provides no evidence” for his theory that cross-reactive immune memory cells triggered by the pneumococcal vaccine could lead to PMR. Id. (citing ECF No. 16-2 at 15). Even assuming that Dr. Efthimiou could support this theory with evidence that such cross-reactive cells might exist or that they could lead to autoimmunity or PMR, 12 Dr. Kinet notes that it is “not clear whether [Dr. Efthimiou] proposes that the cross-reactive cells react with pneumococcal proteins and self-antigens, pneumococcal proteins and influenza antigens, or all three.” Id. Overall, Dr. Kinet concludes that “Dr. Efthimiou does not provide any reliable support for how influenza vaccination might have contributed to or caused [Petitioner’s] symptoms.” Id. c. Petitioner’s Rebuttal Expert Report On October 31, 2024, Petitioner filed a rebuttal report from Dr. Efthimiou responding to Respondent’s expert report. See Pet’r’s Ex. 26, ECF No. 19-1. Dr. Efthimiou emphasizes that his first report demonstrates that “reliable immunological mechanisms support a biological mechanistic ‘theory’ detailing how the immune response to a[n] [influenza] vaccine can adversely contribute at the mechanistic level to pathologically cause clinical symptoms of PMR illness.” Id. at 2. Dr. Efthimiou further asserts that the medical literature supports his “biological mechanistic (scientific) theory explaining how vaccinations can pathologically cause the clinical onset of PMR.” Id. Additionally, the “clinical literature” provides evidence that “the biological mechanisms being discussed, at least in theory, could have actually occurred in another patient.” Id. at 2–3. Thus, Dr. Efthimiou explains, the lack of “biological certainty” as to “the specific innate immune culprit” causing the “adverse immune response” does not “automatically refute or reject” the medical and scientific reliability of Petitioner’s “vaccine causal theory.” Id. at 3. Defending his causal theory, Dr. Efthimiou argues that “the safety of a causal factor should not be confused with whether there is a reliable and plausible biological mechanistic theory for how the two events can, especially in theory, be causally connected.” Id. at 4. In response to Dr. Kinet’s suggestion that the coincidence of two common events does not establish causation, Dr. Efthimiou explains that he is “not trying to establish that vaccine causation is medically certain or accepted in the general population studies.” Id. at 5. Moreover, Dr. Efthimiou defends his reliance 13 on case reports which are published in medical literature for the purpose of “[d]iscussing putative associations,” such as between vaccines and PMR. Id. at 6. Overall, Dr. Efthimiou opines that “there are several biological mechanistic explanations that can reliably describe what can occur at the molecular level of causation” to explain how Petitioner’s vaccines may have triggered PMR. Id. at 14. In Dr. Efthimiou’s medical and scientific opinion either Petitioner’s influenza “vaccine alone was [the] specific immune culprit that initiated an adverse immune response, or the [influenza] vaccine could have adversely influenced the already circulating pneumococcal immune cells present at the time administered.” Id. Dr. Efthimiou concedes, however, that it is impossible to determine, at the molecular level, “which vaccine was ‘more likely’ the specific adverse immune contributor.” Id. 2. Briefing on Entitlement and Petitioner’s Motion to Supplement the Record After the parties filed their expert reports, the Chief Special Master set a briefing schedule for a ruling on the record. See Scheduling Order, Nov. 4, 2024. Because petitions alleging PMR as a vaccine injury “have routinely been dismissed,” the Chief Special Master directed the parties to brief entitlement. See Entitlement Dec. at 1, ECF No. 28. On January 31, 2025, Petitioner filed his Motion for Ruling on the Record, see Pet’r’s Evidentiary Br. Supp. Entitlement, ECF No. 21, as well as an additional piece of medical literature that was “cited in [Dr. Efthimiou’s] rebuttal report” but “was inadvertently not filed,” Notice Filing Ex. 31, ECF No. 20. In his motion, Petitioner argues that he suffered from PMR, a medically recognized rheumatological illness that was caused by his vaccinations. See ECF No. 21 at 1, 13–14, 18–23, 34–36. Following a 45-day extension, see Order Granting Mot. for Extension of Time, Feb. 24, 2025, Respondent filed his response to Petitioner’s brief on April 14, 2025. See Resp. to Pet’r’s Br. Supp. Entitlement, ECF No. 23. Respondent argues that Petitioner fails to offer a reliable medical or scientific theory 14 showing that the vaccines Petitioner received can cause PMR. Id. at 10–13. Petitioner filed his reply on April 30, 2025. See Pet’r’s Rebuttal Br. Supp. Entitlement, ECF No. 24. Nearly seven months later, on November 26, 2025, Petitioner filed a Motion for Leave to Proffer Supplemental Expert Report and Medical Literature. See ECF No. 26. 9 In the motion, Petitioner sought to introduce a supplemental report prepared by Dr. Efthimiou addressing two additional articles of medical literature. See Memo Supp. Pet’r’s Mot. Suppl. Evidentiary R. at 8– 9, ECF No. 26-1; Pet’r’s Ex. 32, Jiyeon Oh et al., Global Burden of Vaccine-Associated Rheumatic Diseases and Their Related Vaccines, 1967–2023: A Comprehensive Analysis of the International Pharmacovigilance Database, 27 Int’l J. Rheumatic Disease 15294 (2024), ECF No. 26-2; Pet’r’s Ex. 33, Koji Hayashi et al., Polymyalgia Rheumatica Following Influenza B Infection: A Case Report, 16 Cureus 70671 (2024), ECF No. 26-3; Pet’r’s Ex. 34, ECF No. 26-4 (proffered supplemental report). Petitioner explains that the articles, both of which were published prior to the filing of Dr. Efthimiou’s rebuttal report and the parties’ subsequent briefing on entitlement, had only “been discovered” during the “intervening seven [] months” as Petitioner’s counsel “continued to work with Dr. Efthimiou” on additional Vaccine Act cases “involving the same general causation theory as [Petitioner’s] particular case.” ECF No. 26 ¶¶ 8–9. The first proffered supplemental article consists of a 2024 study comparing the rates of reports of six types of rheumatic diseases following vaccination to the rates of reports of those same diseases following other environmental triggers. See ECF No. 26-2. According to Dr. Efthimiou, the study “identifie[s] a statistically significant 9 After denying Petitioner’s request, as explained further below, the Chief Special Master ordered the Clerk of Court to strike the motion and associated attachments from the docket. See Order Denying Mot. Suppl. R. at 2, ECF No. 27. Nonetheless, the Court refers to the motion and attachments’ ECF numbers for ease of reference. 15 signal that denoted a positive association” between the influenza vaccine and PMR, as well as the pneumococcal vaccine and PMR. ECF No. 26-4 at 1–2 (citing ECF No. 26-2 at 7 tbl. 3). The second proffered supplemental article is a 2024 report describing a single instance of a patient reporting PMR symptoms following influenza infection. See ECF No. 26-3. Dr. Efthimiou explains that the report exemplifies the continuing publication of “case reports . . . associating the onset of PMR illness with influenza infection.” ECF No. 26-4 at 2 (citing ECF No. 26-3). Petitioner argues that Dr. Efthimiou should be provided with “an opportunity to update his opinions on all similar matters still pending before” the Chief Special Master “to ensure a review of all current medical literature data published prior to issuing an entitlement decision.” ECF No. 26-1 at 8. Petitioner maintains that the additional articles are “highly relevant [] to the issue of causation” and “[f]undamental fairness requires that [Petitioner] be allowed to supplement the record” with them. Id. at 9. 3. The Chief Special Master’s Denial of Petitioner’s Motion to Supplement the Record The Chief Special Master issued an Order denying supplementation on December 1, 2025. See Order Denying Mot. Suppl. R., ECF No. 27. The Chief Special Master explained that Petitioner “provides no reasonable explanation for why” the two additional articles “could not have been [included] at the time [Petitioner] was briefing his claim.” Id. at 1. “[B]oth items of literature were published in 2024,” the Chief Special Master emphasized, “and thus do not reflect newly- published studies that were unavailable.” Id. (emphasis in original). The Chief Special Master rejected Petitioner’s “fundamental fairness” arguments as “stretch[ing] Program goals of fairness . . . well beyond their breaking point.” Id. at 1–2. Indeed, the Chief Special Master observed that “claims would never be resolved” if petitioners could “merely seek[] to take advantage of the time that has elapsed since [a] matter was briefed to bulwark [their] argument further.” Id. at 2. Finally, the Chief Special Master determined that Petitioner’s proffered evidence 16 was “not particularly integral to the claim’s resolution.” Id. Accordingly, the Chief Special Master denied Petitioner’s Motion. Id. 4. The Chief Special Master’s Entitlement Decision The Chief Special Master also issued his Entitlement Decision on December 1, 2025, finding a lack of preponderant evidence supporting Petitioner’s causation theory. See ECF No. 28 at 23. In the decision, the Chief Special Master reviewed Petitioner’s medical records, id. at 2–4; the parties’ expert reports, id. at 4–10; the parties’ arguments, id. at 10–13; and the applicable law, id. at 13–19, before concluding that Petitioner failed to sufficiently establish a medical theory showing that the influenza or pneumococcal vaccines can cause PMR, id. at 20–23. The Chief Special Master’s analysis proceeded in two parts: first, he reviewed the Vaccine Program’s general treatment of PMR, id. at 20–21; and second, he analyzed Dr. Efthimiou’s specific causation theory alongside Dr. Kinet’s report, id. at 21–23. The Chief Special Master began his analysis of the Vaccine Program’s general treatment of PMR by noting that PMR “has not generally been deemed in the [Vaccine] Program to be vaccine-caused.” Id. at 20 (emphasis in original). In support of this observation, the Chief Special Master cited seven cases—two of which were decided by the Chief Special Master—rejecting similar theories attempting to demonstrate that vaccines can cause PMR. Id. The Chief Special Master found Thompson v. Secretary of Health & Human Services, No. 18-1217V, 2023 WL 9053982 (Fed. Cl. Spec. Mstr. Dec. 5, 2023), to be “on-point” because it “also involve[d] the pneumococcal vaccine.” ECF No. 28 at 20. Several of the other cited decisions (including those of the Chief Special Master) rejected similar causal theories that sought to establish that the influenza vaccine can cause PMR. See id. at 20–21. The Chief Special Master also noted his “specific[] familiar[ity] with the form of causation theory articulated by Dr. Efthimiou” because Dr. Efthimiou had “previously proposed a comparable theory in” another case the Chief Special 17 Master decided, Munoz v. Secretary of Health & Human Services (Munoz I), No. 21-1369V, 2024 WL 4113486 (Fed. Cl. Spec. Mstr. Aug. 12, 2024). ECF No. 28 at 21. The Chief Special Master also analyzed Dr. Efthimiou’s specific causal theory as it pertains to Petitioner’s circumstances. Id. at 21–23. The Chief Special Master found that Dr. Efthimiou failed to: (a) “show a relationship between the [influenza] or pneumococcal vaccine’s wild infectious analogs and PMR”; (b) “identify a specific antigen associated with the development of PMR”; (c) “persuasively explain (other than by generalities about the immune process) how the specific vaccines in question would cause immune harm resulting in PMR symptoms simply due to innate immune stimulation”; or (d) “demonstrate that Petitioner himself possessed any genetic susceptibility making an adverse reaction resulting in PMR more likely.” Id. at 22. Conversely, the Chief Special Master found that “Dr. Kinet effectively and persuasively rebutted Petitioner’s causation contentions, showing that PMR is a common malady, and has little in the way of known triggers or mechanistic explanations.” Id. Overall, the Chief Special Master concluded that Petitioner’s causal theory sought to convert the vaccines’ “understood capacity to provoke some immune response[] into something pathogenic, but without sufficient probative evidence to connect all the dots.” Id. In other words, “[t]he fact that vaccines provoke an innate response does not mean that response causes injury.” Id. Ultimately, the Chief Special Master determined that Petitioner lacked “sufficient probative evidence allowing for the conclusion that it is more likely than not that [influenza] and/or pneumococcal vaccine components can trigger PMR, alone or in combination.” Id. Rather, Petitioner’s theory involved “too many speculative assumptions about