       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

      H.L., ON BEHALF OF, A.I., DECEASED,
                Petitioners-Appellants

                           v.

      SECRETARY OF HEALTH AND HUMAN
                  SERVICES,
              Respondent-Appellee
             ______________________

                      2017-1218
                ______________________

    Appeal from the United States Court of Federal
Claims in No. 1:10-vv-00197-SGB, Chief Judge Susan G.
Braden.
                ______________________

              Decided: November 1, 2017
               ______________________

   ROBERT JOEL KRAKOW, Law Office of Robert J. Kra-
kow, New York, NY, argued for petitioners-appellants.

    ROBERT PAUL COLEMAN, III, Torts Branch, Civil
Division, United States Department of Justice, Washing-
ton, DC, argued for respondent-appellee. Also represent-
ed by CHAD A. READLER, CATHARINE E. REEVES, HEATHER
L. PEARLMAN.
                 ______________________
2                                                 H.L.   v. HHS




 Before LOURIE, O’MALLEY, and TARANTO, Circuit Judges.
O’MALLEY, Circuit Judge.
     This case arises from the tragic death of a six-year-old
girl, A.I., who suffered from Leigh disease, an inherited
mitochondrial disorder that affects the central nervous
system. A.I. passed away several months after receiving
a live attenuated influenza vaccine, sold under the brand
name FluMist® Quadrivalent.          Thereafter, Petitioner
H.L., A.I.’s mother, filed a petition for compensation
under the National Childhood Vaccine Injury Act of 1986
(codified as amended at 42 U.S.C. §§ 300aa–1 to –34)
(“Vaccine Act”), alleging that A.I.’s death was caused in
part by the FluMist vaccine. According to H.L., the
FluMist vaccine, in combination with an upper respirato-
ry infection, significantly aggravated A.I.’s Leigh disease,
leading to metabolic decompensation, and, ultimately, to
her death.
    The special master denied compensation, H.L. v. Sec’y
of Health & Human Servs., No. 10-0197V, 2016 WL
3751848 (Fed. Cl. Spec. Mstr. Mar. 17, 2016) (“Special
Master Decision”), and the United States Court of Federal
Claims affirmed, H.L. v. Sec’y of Health & Human Servs.,
129 Fed. Cl. 165 (2016). Because the Court of Federal
Claims correctly concluded that the special master’s
decision was not arbitrary, capricious, an abuse of discre-
tion, or otherwise not in accordance with law, we affirm.
                      I. BACKGROUND
                  A. Factual Background
    A.I. was born more than eight weeks premature on
December 7, 2001, and was not discharged from the
hospital until approximately two months later. Special
Master Decision, 2016 WL 3751848, at *4. As an infant,
A.I. was treated for common infections, and, although she
H.L.   v. HHS                                              3



developed fevers on multiple occasions, she recovered
from each without incident. Id.
     After A.I.’s first birthday, however, she began exhibit-
ing developmental delays. When A.I. was approximately
fourteen-months old, for example, A.I.’s doctors noted in
her medical records that she exhibited motor and possible
speech delay, which they again noted when A.I. was
sixteen- and eighteen-months old. Id. at *5. When A.I.
was thirty-months old, her doctors noted that she was a
late walker and fell down frequently. Id. And just before
her third birthday, A.I.’s doctors examined A.I. after she
fell and hit her head, and observed that she appeared
“wobbly” when she walked. Id.
    On January 11, 2008, when she was six-years old, A.I.
visited her pediatrician following two days of coughing
and a fever registering 102° F that morning. Id. By the
time of her examination, however, A.I.’s fever had de-
creased to 100.3° F. Id. A.I.’s pediatrician diagnosed her
as having an upper respiratory infection and adminis-
tered the FluMist vaccine. Id. Later that evening, A.I.
began experiencing “staring spells” during which she
stared vacantly off into space and failed to respond to
stimuli. 1 Id. & n.3. Although her upper respiratory
infection improved by January 16, A.I. continued to feel
unwell and stayed home from school for the next few days.
Id.
    On January 22, once back at school, A.I. experienced a
series of collapses and was taken to the emergency room,



       1The special master noted that there is no docu-
mentation supporting H.L.’s testimony that A.I. experi-
enced staring spells on the day she was vaccinated.
Special Master Decision, 2016 WL 3751848, at *5 n.3.
The special master nevertheless accepted H.L.’s testimony
that A.I. experienced such staring spells. Id.
4                                                 H.L.   v. HHS



where she again exhibited staring spells and intermittent
weakness in her lower extremities. Id. at *6. Nearly one
month later, A.I.’s neurologist concluded, based on an
MRI scan and her symptoms, that A.I. was likely suffer-
ing from Leigh disease. Subsequent DNA testing con-
firmed this diagnosis. 2 Id.
     On March 15, 2008, A.I. was taken by ambulance to
the hospital after experiencing unconsciousness and
difficulty breathing. Id. A.I. continued exhibiting respir-
atory and swallowing difficulties, and eventually under-
went surgery for a gastrostomy tube placement. Id. at *7.
Following surgery, an MRI showed a worsening of the
lesions in A.I.’s brain consistent with Leigh disease. Id.
Over the next few weeks, A.I.’s condition continued to
deteriorate until she became unresponsive. A.I. passed
away on April 5, 2008. Id. Although “Leigh Syndrome”
was listed as the cause of death, no autopsy was per-
formed. Id.
                  B. Procedural History
    H.L., on behalf of A.I., filed a petition for compensa-
tion on April 1, 2010, alleging that the FluMist vaccine, in
conjunction with A.I.’s upper respiratory infection, signifi-
cantly aggravated her preexisting Leigh disease. On
March 17, 2016, after hearing live testimony from the
parties and their experts, the special master issued a
detailed decision denying H.L.’s petition.
    At the outset, the special master emphasized that he
found H.L.’s expert’s view of the case to be “quite unper-
suasive” compared to that of the government’s expert,
particularly because H.L.’s expert “sought to make infer-


    2   Although A.I.’s Leigh disease was not diagnosed
until after she received her vaccination, neither party
disputes that A.I.’s Leigh disease was a preexisting condi-
tion.
H.L.   v. HHS                                            5



ential leaps not supported by the record” and “effectively
admitted that certain aspects of her causation opinion
were speculative.” Id. at *10. The special master found
that neither A.I.’s medical records nor H.L.’s expert’s
opinion established a causal connection between the
vaccine and A.I.’s condition. Based on his assessment of
the evidence presented, the special master concluded that
H.L. had failed to satisfy any of the three prongs of the
governing test set forth in Althen v. Secretary of Health &
Human Services, 418 F.3d 1274, 1278 (Fed. Cir. 2005).
    In particular, the special master rejected the testimo-
ny of H.L.’s expert—Dr. Kendall—that, because A.I. did
not experience metabolic decompensation after suffering
from prior, more severe illnesses, her upper respiratory
infection required the additional stress of the FluMist
vaccination to overwhelm A.I.’s system. Special Master
Decision, 2016 WL 3751848, at *12. The special master
noted that the government’s expert—Dr. McCandless—
testified, as Dr. Kendall conceded, that the cause of
metabolic decompensation in Leigh disease patients is
unpredictable, and that there is not always any identifia-
ble precipitating factor. Id. The special master also
rejected as evidence of causation certain post-marketing
information in FluMist’s packaging insert that reports
instances of exacerbation of Leigh disease. The special
master found that the insert did not report any details
and therefore “is simply not informative of any causal
connection.” Id. at *13–14.
    The special master also found that Dr. Kendall drew
inferences from several articles on which she relied that
were not supported by the articles themselves. The
articles, for example, described autistic regression—which
A.I. did not experience—in patients suffering from mito-
chondrial diseases, but did not discuss the particular
mitochondrial disease from which A.I. suffered. Id. at
*14. The special master found that Dr. Kendall failed to
show sufficient similarity between the injuries sustained
6                                                 H.L.   v. HHS



by the patients studied in those articles and A.I.’s decline.
Id. at *14–17. Other articles cited by Dr. Kendall sug-
gested that a different strain of flu virus—the wild flu
virus—could lead to cell death, but the special master
found that H.L. did not show why one could draw a simi-
lar conclusion for the live attenuated influenza strain in
the FluMist vaccine. Id. at *17–18.
     Finally, the special master rejected Dr. Kendall’s as-
sertion that the FluMist vaccination was temporally
related to the onset of A.I.’s decompensation. In particu-
lar, the special master found it unlikely that the vaccine
was capable of causing A.I.’s staring spells, which oc-
curred just hours after the vaccination. Id. at *10–11. He
noted that Dr. McCandless proffered a study showing that
there is typically a period of three to seven days between
the time of an infection and the onset of neurological
symptoms, and that such onset usually occurs at a time
when the infection is resolving. Id. at *11. Relying in
part on this study, the special master found that A.I.’s
staring spells were more likely the result of her upper
respiratory infection. Id. Accordingly, the special master
rejected H.L.’s claim that A.I.’s decompensation was
temporally related to the FluMist vaccine.
    On April 18, 2016, H.L. filed a motion for review of
the special master’s decision with the Court of Federal
Claims. The court denied that motion, see H.L., 129 Fed.
Cl. 165, and H.L. timely appealed to this court. We have
jurisdiction under 28 U.S.C. § 1295(a)(3) and 42 U.S.C.
§ 300aa–12(f).
                        DISCUSSION
                  A. Standard of Review
    We review an appeal from the Court of Federal
Claims in a Vaccine Act case de novo, applying the same
standard of review the Court of Federal Claims applied to
the special master’s decision. Milik v. Sec’y of Health &
H.L.   v. HHS                                             7



Human Servs., 822 F.3d 1367, 1375 (Fed. Cir. 2016). We
review the special master’s factual findings, however,
under the arbitrary and capricious standard. Id. at 1376.
     H.L. acknowledges our deferential standard of review
for factual findings. See Appellant’s Br. at 48. She never-
theless urges, “for purposes of preservation on appeal,”
that the court undertake de novo review of such findings.
Id. We heard and rejected a similar request in Milik. We
rejected the argument that the Vaccine Act unconstitu-
tionally denies access to de novo review in an Article III
court, and held that it is appropriate to “continue to
review the special master’s findings of fact under the
deferential arbitrary and capricious standard.” Milik, 822
F.3d at 1378–79. We are bound by our holding in Milik. 3
We therefore apply the arbitrary and capricious standard
of review in this case.
                B. The Special Master’s Decision Is
                 Neither Arbitrary Nor Capricious
    Recognizing that vaccines can cause serious adverse
side effects in rare circumstances, Congress enacted the
Vaccine Act to allow claimants to recover for certain
vaccine-related injuries, including those that significantly
aggravate a preexisting condition. 4      Id. at 1374–75;



       3On November 29, 2016, the petitioners in Milik
filed a petition for a writ of certiorari with the Supreme
Court. On May 30, 2017, after briefing in this case closed,
the Court denied that petition. See Milik v. Price, 137 S.
Ct. 2206 (2017).
     4  The Vaccine Act defines “significant aggravation”
as “any change for the worse in a preexisting condition
which results in markedly greater disability, pain, or
illness accompanied by substantial deterioration of
health.” 42 U.S.C. § 300aa–33(4).
8                                                 H.L.   v. HHS



Whitecotton v. Sec’y of Health & Human Servs., 81 F.3d
1099, 1106–07 (Fed. Cir. 1996).
    A petitioner seeking compensation must show “that
the injury or death at issue was caused by a vaccine.”
Broekelschen v. Sec’y of Health & Human Servs., 618 F.3d
1339, 1341 (Fed. Cir. 2010) (citing 42 U.S.C. §§ 300aa–
11(c)(1), –13(a)(1)). Where the petitioner alleges that a
vaccination caused an injury that is not listed on the
Vaccine Injury Table (codified at 42 U.S.C. § 300aa–14),
the petitioner must establish causation-in-fact by show-
ing, by a preponderance of the evidence: (1) a medical
theory causally connecting the vaccination and the injury;
(2) a logical sequence of cause and effect showing that the
vaccination was the reason for the injury; and (3) a prox-
imate temporal relationship between vaccination and
injury. 5 Althen, 418 F.3d at 1278.
    H.L. argues that the special master erred in finding
that she failed to carry her burden with respect to each of
the three Althen prongs. H.L.’s arguments, however, are
largely predicated on challenges to the special master’s
factual findings and are therefore foreclosed by the
heightened standard of review applicable on appeal. As
we have explained, “[t]he arbitrary and capricious stand-
ard is ‘difficult for an appellant to satisfy with respect to
any issue, but particularly with respect to an issue that


    5   For significant aggravation cases such as this one,
the petitioner must also describe the vaccinee’s pre- and
post-vaccination medical condition and demonstrate that
the post-vaccination condition constitutes a significant
aggravation. See W.C. v. Sec’y of Health & Human Servs.,
704 F.3d 1352, 1357 (Fed. Cir. 2013); Loving v. Sec’y of
Health & Human Servs., 86 Fed. Cl. 135, 144 (2009). The
special master found that H.L. satisfies these additional
requirements, Special Master Decision, 2016 WL 3751848,
at *20, and the government does not dispute that finding.
H.L.   v. HHS                                             9



turns on the weighing of evidence by the trier of fact.’”
Milik, 822 F.3d at 1376 (quoting Lampe v. Sec’y of Health
& Human Servs., 219 F.3d 1357, 1360 (Fed. Cir. 2000)).
Indeed, as long as the special master’s “conclusion [is]
based on evidence in the record that [is] not wholly im-
plausible, we are compelled to uphold that finding as not
being arbitrary or capricious.” Cedillo v. Sec’y of Health &
Human Servs., 617 F.3d 1328, 1338 (Fed. Cir. 2010)
(internal quotation marks omitted). As explained below,
the special master’s decision here is based on the record
evidence and is not wholly implausible.
    Each of H.L.’s arguments as to why the special master
erred fails. First, H.L. argues that the special master
“diminished” Dr. Kendall’s opinion that A.I.’s ability to
tolerate prior illnesses suggests that the additional oxida-
tive stress placed on her system from the vaccination
contributed to her decompensation in this case. Appel-
lant’s Br. at 37. H.L. further asserts that the special
master improperly “heightened” and “shifted” her burden
by requiring H.L. to quantify the stress levels needed to
provoke decompensation and to differentiate the stresses
attributable to the FluMist vaccine and the upper respira-
tory infection, which H.L. asserts is impossible to do. Id.
at 23–27. While H.L.’s burden in this context was un-
doubtedly a difficult one to satisfy, we cannot say that the
special master’s assessment of the evidence presented was
arbitrary or capricious.
     As petitioner, H.L. carried the burden to prove her
theory of causation by a preponderance of the evidence.
See Broekelschen, 618 F.3d at 1346. H.L.’s theory from
the start was that the FluMist vaccination, in combina-
tion with A.I.’s upper respiratory infection, aggravated
A.I.’s Leigh disease so as to cause metabolic decompensa-
tion. See Oral Argument at 1:00–1:22, H.L. v. Sec’y of
Health & Human Servs. (No. 17-1218), http://oral
arguments.cafc.uscourts.gov/default.aspx?fl=2017-1218
.mp3 (conceding that the FluMist vaccine, in combination
10                                                H.L.   v. HHS



with A.I.’s respiratory infection and Leigh disease, con-
tributed to her decompensation). To prevail on that
theory, therefore, H.L. was required to show that the
FluMist vaccine—and not just A.I.’s upper respiratory
infection—was a but-for cause and a contributing factor to
A.I.’s decompensation. See Shyface v. Sec’y of Health &
Human Servs., 165 F.3d 1344, 1352 (Fed. Cir. 1999).
     The special master determined that H.L. failed to
meet that burden. In particular, the special master
found—and both experts agreed—that there often is no
trigger for decompensation among patients suffering from
Leigh disease, and that Leigh disease often results in
premature death. Special Master Decision, 2016 WL
3751848, at *12. The special master further found that
Dr. Kendall’s theory of causation was mere “speculation.”
Id. Although Dr. McCandless acknowledged that it is
“possible” for infection, in the absence of fever, to cause
decompensation, and that the attenuated influenza virus
could increase metabolic need, J.A. 282–84, he further
testified that “it’s extremely unlikely” that the vaccination
was the cause of A.I.’s decompensation in this case, Spe-
cial Master Decision, 2016 WL 3751848, at *9; J.A. 293.
The special master weighed the evidence and concluded
that H.L. did not establish that the FluMist vaccine was a
but-for cause of A.I.’s decompensation. That finding
supports the special master’s conclusions at Althen prongs
1 and 2. See Pafford v. Sec’y of Health & Human Servs.,
451 F.3d 1352, 1357–58 (Fed. Cir. 2006) (affirming deci-
sion denying relief where “the Special Master concluded
he was unable to tell whether any of the vaccinations
made any contribution to” the injury). Because H.L.
failed to establish a prima facie case of causation, the
burden never shifted to the government to prove other-
wise. Cedillo, 617 F.3d at 1338.
    Second, H.L. argues that the special master improper-
ly discounted the post-marketing information in FluMist’s
package insert, which states that the vaccination could
H.L.   v. HHS                                            11



exacerbate symptoms in patients suffering from Leigh
disease. But, as the special master found and as Dr.
Kendall acknowledged, the package insert does not de-
scribe a contraindication, and the medical community
largely agrees that vaccines should be administered to
individuals with metabolic disorders. Special Master
Decision, 2016 WL 3751848, at *13. Dr. McCandless also
testified that the post-marketing information is mandated
by the FDA to ensure that potential issues may be inves-
tigated, and contains no details regarding the specific
instances referred to therein. Id. Thus, as the post-
marketing information itself states, “it is not always
possible to reliably estimate” the frequency of adverse
reactions to the vaccine “or establish a causal relationship
to vaccine exposure.” J.A. 1914. Given this evidence, the
special master was entitled to find that the post-
marketing information is not probative of causation.
     Third, H.L. argues that the special master failed to
place appropriate weight on articles proffered by Dr.
Kendall. But, as the special master noted, these articles
discuss circumstances that are not directly analogous to
A.I.’s case. The single patient described in John S. Poling
et al., Developmental Regression and Mitochondrial
Dysfunction in a Child with Autism, 21 J. CHILD
NEUROLOGY 170 (2006) (“Poling”), for example, experi-
enced an autistic regression, and did not have Leigh
disease. Although the special master did “not entirely
discount[] the evidentiary value of the Poling report,” he
found that Dr. Kendall provided no evidence supporting
the notion that autistic regression can be equated to
metabolic decompensation, making it nearly impossible to
draw any meaningful inferences from Poling. Special
Master Decision, 2016 WL 3751848, at *14–15. As the
special master noted, “[e]stablishing a theory that a
vaccine can cause injury ‘X’ is not the same as proving
that it can cause injury ‘Y,’ absent some evidence showing
that injuries X and Y share sufficient commonality.” Id.
12                                              H.L.   v. HHS



at *14 n.16. The special master determined that H.L. did
not proffer any evidence showing such commonality. And
even if the case studied in Poling were similar to A.I.’s
case, the special master concluded that Dr. Kendall’s
testimony that decompensation in Leigh disease patients
can occur without any known stressor “dramatically
undercuts” her reliance on Poling. Id. at *15. Again, we
do not find this conclusion to be arbitrary.
    The special master made similar findings with respect
to the other articles cited by H.L. 6 Id. at *15–16. For
example, the special master determined that the articles
addressing the wild flu virus’s effect on cells are inappo-
site, as they are not informative as to whether the same
mechanism applies to an attenuated flu vaccine, where
infection is not expected. Id. at *17–18. These findings
too are neither arbitrary nor capricious, and further
support the special master’s findings at Althen prongs 1
and 2.
    Finally, citing to our recent decision in Paluck v.
Secretary of Health & Human Services, 786 F.3d 1373
(Fed. Cir. 2015), H.L. argues that the special master erred
in finding that the onset of A.I.’s symptoms occurred too
soon after the vaccination to have been attributable to the
FluMist vaccine. But Paluck is distinguishable.
     In Paluck, a one-year old boy developed, over the
course of several months, severe neurodegeneration
following MMR, varicella, and pneumococcal vaccinations.
See Paluck, 786 F.3d at 1375–77. The special master in



     6  See John Shoffner et al., Fever Plus Mitochondrial
Disease Could Be Risk Factors for Autistic Regression, 25
J. CHILD NEUROLOGY 429 (2009); Michael T. Brady, Im-
munization Recommendations for Children with Metabolic
Disorders: More Data Would Help, 118 PEDIATRICS 810
(2006).
H.L.   v. HHS                                           13



that case found that the petitioners did not meet their
burden of proof under the Vaccine Act because they failed
to show that their child manifested symptoms within the
timeframe suggested by the medical literature. Id. at
1383–84. On appeal, we held that the special master
erred by imposing a strict time constraint for the onset of
the vaccinee’s neurodegeneration. We observed that
mitochondrial disorders “are as yet poorly understood by
the medical community,” and that the special master
therefore “had no reasonable basis for setting a hard and
fast deadline of three weeks for the onset of neurological
symptoms.” Id. at 1384.
    Here, the special master did not set a hard-and-fast
deadline based on the medical literature, as even H.L.’s
counsel conceded at oral argument. See Oral Argument at
10:00–10:15 (acknowledging that the special master did
“not necessarily [impose] a hard-and-fast rule”). In fact,
the special master emphasized that the study on which he
relied was “not dispositive” of his analysis, and that Dr.
Kendall’s claim of a temporal relationship was “specula-
tive” “with or without” reference to the study. Special
Master Decision, 2016 WL 3751848, at *11. The special
master relied on the study merely to show that the tem-
poral relationship between the FluMist vaccine and A.I.’s
symptoms makes the “vaccination an unlikely explanation
for A.I.’s metabolic decompensation.” Id. at *22. The
special master’s “requirement for strong temporal evi-
dence” in this regard does not contravene Paluck and is
“consistent with the third prong of the Althen test.”
Pafford, 451 F.3d at 1358; De Bazan v. Sec’y of Health &
Human Servs., 539 F.3d 1347, 1352 (Fed. Cir. 2008)
(noting that, where onset occurs too soon after vaccina-
tion, “the temporal relationship is not such that it is
medically acceptable to conclude that the vaccination and
the injury are causally linked”).
   The special master further noted that, because Dr.
Kendall proffered no evidence regarding the expected
14                                               H.L.   v. HHS



timing of neurologic deterioration, the government’s study
was the “only evidence in th[e] record regarding” such
timing. Special Master Decision, 2016 WL 3751848, at
*11. The study teaches that patients typically manifest
neurological symptoms within a few days after infection
and as the infection is resolving. Similarly, here, A.I.
experienced staring spells mere hours after the vaccina-
tion, but days after having contracted her upper respira-
tory infection, and while her infection was resolving.
Among the “two competing expert opinions,” the special
master found that Dr. McCandless’s opinion was “more
persuasive” on this point, and that A.I.’s symptoms were
more likely to be attributable to her upper respiratory
infection than to the FluMist vaccination. Id. We are not
at liberty to reweigh the factual evidence and assess the
credibility of the parties’ experts, as H.L. apparently asks
us to do. See Milik, 822 F.3d at 1380. 7
    The special master’s findings are not arbitrary or
capricious, and those findings support the special master’s
conclusion that H.L. has failed to satisfy each of the
Althen prongs.




     7   H.L. asserts that A.I.’s first “major” symptoms
were not her staring spells, but rather her collapses on
January 22, 2008—eleven days after the vaccination.
Appellant’s Br. at 32. While it is true that Dr. Kendall
testified that A.I.’s onset culminated with her collapses,
Dr. Kendall stated that A.I.’s first symptoms were her
staring spells.      Special Master Decision, 2016 WL
3751848, at *10. In any event, the special master consid-
ered H.L.’s argument, and found that he would still have
rejected H.L.’s causation claim for the other reasons
discussed above. Id. at *11 n.8.
H.L.   v. HHS                                            15



                     III. CONCLUSION
    While we sympathize with H.L. for the tragic loss of
her daughter, and may have weighed some of the evidence
differently in the first instance, we conclude that H.L. has
not shown that the special master committed reversible
error. We therefore affirm the Court of Federal Claims’
decision.
                       AFFIRMED
                          COSTS
       No costs.
