Case: 23-1894 Document: 38 Page: 1 Filed: 08/20/2024

NOTE: This disposition is nonprecedential.

United States Court of Appeals for the Federal Circuit ______________________ DEIDRE HENKEL, ALEX HENKEL, AS PARENTS OF V.H., A MINOR, Petitioners-Appellants v. SECRETARY OF HEALTH AND HUMAN SERVICES, Respondent-Appellee ______________________ 2023-1894 ______________________ Appeal from the United States Court of Federal Claims in No. 1:15-vv-01048-LAS, Senior Judge Loren A. Smith. ______________________ Decided: August 20, 2024 ______________________ EDWARD KRAUS, Kraus Law Group, LLC, Chicago, IL, argued for petitioners-appellants. Also represented by BRYNNA GANG.

MADYLAN LOUISE YARC, Torts Branch, Civil Division, United States Department of Justice, Washington, DC, ar- gued for respondent-appellee. Also represented by BRIAN M. BOYNTON, C. SALVATORE D'ALESSIO, HEATHER LYNN PEARLMAN, RYAN D. PYLES, DARRYL R. WISHARD.

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______________________ Before MOORE, Chief Judge, PROST, Circuit Judge, and MAZZANT, District Judge. 1 PROST, Circuit Judge.

V.H.’s parents, Deidre and Alex Henkel (“Appellants”), filed a petition with the U.S. Court of Federal Claims under the National Vaccine Injury Compensation Program, which was established by the National Childhood Vaccine Injury Act of 1986 (“Vaccine Act”). The petition alleged that V.H. developed narcolepsy from the FluMist vaccine, and it sought compensation for that injury. A special mas- ter denied the petition; the Court of Federal Claims sus- tained that denial; and Appellants appeal, see 42 U.S.C. § 300aa-12(f). We have jurisdiction under 28 U.S.C. § 1295(a)(3).

For the reasons below, we affirm. Because we write for the parties, we omit from this opinion other details of the factual and procedural background.

I In Vaccine Act cases, we review the Court of Federal Claims’ decision de novo. E.g., Dupuch-Carron v. Sec’y of HHS, 969 F.3d 1318, 1324 (Fed. Cir. 2020). Effectively, “we perform the same task as the Court of Federal Claims and determine anew whether the special master’s findings were arbitrary or capricious.” Deribeaux ex rel. Deribeaux v. Sec’y of HHS, 717 F.3d 1363, 1366 (Fed. Cir. 2013) (cleaned up); see 42 U.S.C. § 300aa-12(e)(2)(B) (providing that, when reviewing a special master’s decision, the Court of Federal Claims may “set aside any findings of fact or

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conclusion of law . . . found to be arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law”).

Because this case involves an off-Table injury, Appel- lants must prove causation by establishing each of the three Althen prongs with preponderant evidence. Boatmon v. Sec’y of HHS, 941 F.3d 1351, 1355 (Fed. Cir. 2019) (citing Althen v. Sec’y of HHS, 418 F.3d 1274, 1278 (Fed. Cir. 2005)). The three Althen prongs are: (1) a medical theory causally connecting the vaccination and the injury; (2) a logical sequence of cause and effect showing that the vac- cination was the reason for the injury; and (3) a showing of a proximate temporal relationship between vaccination and injury. Althen, 418 F.3d at 1278.

The special master found that Appellants carried their burden of proof for Althen prong one but not prongs two or three. See Henkel v. Sec’y of HHS, No. 15-1048V, 2022 WL 16557979, at *43–47 (Fed. Cl. Aug. 31, 2022). Because we conclude that the special master’s finding on Althen prong three was not arbitrary or capricious (or otherwise errone- ous), and because Appellants needed to prevail on all three prongs to have their petition granted, we affirm the peti- tion’s denial without reaching the prong-two finding.

II Establishing Althen prong three “requires preponder- ant proof that the onset of symptoms occurred within a timeframe for which, given the medical understanding of the disorder’s etiology, it is medically acceptable to infer causation-in-fact.” de Bazan v. Sec’y of HHS, 539 F.3d 1347, 1352 (Fed. Cir. 2008).

The special master found—and Appellants do not dis- pute—that V.H.’s narcolepsy symptom onset began approx- imately four-to-six weeks after the relevant FluMist Case: 23-1894 Document: 38 Page: 4 Filed: 08/20/2024

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vaccination. 2 Henkel, 2022 WL 16557979, at *46. The spe- cial master also found, however, that this four-to-six-week timeframe lacked sufficient evidentiary support as an ap- propriate timeframe for symptom onset in this case. See id. In particular, the special master found that the study described in the Han article (“Han”)3 indicated that narco- lepsy symptom onset possibly associated with H1N1 influ- enza infection began six months after such infection. The special master also found that the Ahmed article (“Ah- med”) 4—which Appellants’ expert co-authored—character- ized Han as indicating such a six-month timeframe. Six months, however, was “not the timeframe proposed by [Ap- pellants] as appropriate in this case.” Id. The special mas- ter further found that, although Appellants’ expert had opined that four-to-six weeks was appropriate for a “recall response”—that is, a response to a subsequent vaccine dose after receiving an earlier one—the expert had “not ex- plained how a recall response would impact the timing of disease onset” in a way relevant to this case. See id. Appellants disagree with the special master’s finding that they failed to carry their burden of proof for Althen prong three. But they have not persuaded us that this find- ing was arbitrary, capricious, an abuse of discretion, or oth- erwise not in accordance with law.

For example, Appellants argue that the special master misinterpreted Han. They maintain that Han’s six-month timeframe referred to the time from infection to a narco- lepsy diagnosis—not, as the special master thought, the

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time to symptom onset. See Appellants’ Br. 46–47. Yet, as the government persuasively notes, Han suggests that the latter is indeed the proper interpretation, in part because Han hypothesizes the reason for this timeframe as: “[A]pproximately 80% cell loss is needed to exhibit symp- toms, possibly explaining the 4- to 6-month delay between winter airway infection and narcolepsy onset occurrence.”

J.A. 2150; see also J.A. 2147 (describing results in terms of onset, “when onset was defined by the appearance of either sleepiness or cataplexy, a more objective symptom”); J.A. 1182 (Ahmed: “The time to narcolepsy onset following influenza infection was six months [in Han].”). At the very least, we cannot say that the special master’s interpreta- tion of Han’s six-month timeframe as the time to symptom onset reflects a decision that was arbitrary, capricious, or an abuse of discretion.

Appellants also cite Ahmed as showing that approxi- mately two months is the proper timeframe from an influ- enza vaccination to any resultant narcolepsy symptom onset. See Appellants’ Br. 42, 46 (citing J.A. 1182 (describ- ing “an onset approximately two months after vaccina- tion”)). Setting aside that, as the special master observed, this passage of Ahmed was discussing an influenza vaccine different from FluMist, see Henkel, 2022 WL 16557979, at *46 (observing that Ahmed was discussing the Pan- demrix vaccine), the government notes that this timeframe is still longer than four-to-six weeks. Appellants reply that, “to the extent 4-6 weeks is on the quicker side of ap- proximately two months,” their expert testified that a re- call response explained any quicker symptom onset.

Appellants’ Reply Br. 9 (citing J.A. 740); see also Appel- lants’ Br. 43 (citing J.A. 663–64, 714–15). But the special master determined that Appellants’ expert had “not ex- plained how a recall response would impact the timing of disease onset” in a way relevant to this case. See Henkel, 2022 WL 16557979, at *46. And, having reviewed Appel- lants’ identified expert testimony, we are not persuaded Case: 23-1894 Document: 38 Page: 6 Filed: 08/20/2024

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that the special master’s determination in this regard re- flects a decision that was arbitrary, capricious, or an abuse of discretion.

Appellants finally argue that, in evaluating Althen prong three, the special master applied an improperly ele- vated standard of proof—one more demanding than the preponderance standard. See, e.g., Appellants’ Br. 49 (ar- guing that the special master’s prong-three finding was “against the weight of the evidence and based on an ele- vated burden of proof”). We see no indication that the spe- cial master held Appellants to an improperly elevated standard when assessing Althen prong three. The special master’s decision accurately set forth the governing stand- ard as preponderant evidence. See, e.g., Henkel, 2022 WL 16557979, at *1, *35. And, in discussing Althen prong three specifically, the special master found that, because Appellants had “provided insufficient evidence in this case of what an appropriate timeframe between V.H.’s second FluMist vaccination and narcolepsy onset would be,” they had “not provided preponderant evidence of a proximate temporal relationship between V.H.’s vaccination and nar- colepsy onset.” Id. at *46.

In this case, Appellants’ standard-of-proof challenge simply reflects their disagreement with how the special master weighed their evidence. As discussed above, how- ever, we do not deem the special master’s assessment of the evidence to be arbitrary or capricious. See, e.g., Broekelschen v. Sec’y of HHS, 618 F.3d 1339, 1349 (Fed. Cir. 2010) (“This court does not reweigh the factual evidence[] or assess whether the special master correctly evaluated the evidence. . . . These are all matters within the purview of the fact finder.” (cleaned up)). And we oth- erwise see no abuse of discretion or legal error in the spe- cial master’s ultimate determination regarding Althen prong three.

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III We have considered Appellants’ remaining arguments and find them unpersuasive. For the foregoing reasons, we affirm.

AFFIRMED COSTS No costs.