           In the United States Court of Federal Claims
                                         No. 10-489V
                            (Filed Under Seal: February 26, 2014)
                          (Reissued for Publication: March 21, 2014)1

*************************************
VALERIA FLORES,                     *
                                    *
                  Petitioner,       *                Vaccine Act; Motion for Review; HPV
                                    *                Vaccine; Spinal Cord Stroke; Althen;
 v.                                 *                Causation-in-Fact; Burden of Proof; Genetic
                                    *                Susceptibility; Medical Literature;
SECRETARY OF HEALTH AND             *                Unknown Etiology; Logical Sequence of
HUMAN SERVICES,                     *                Cause and Effect
                                    *
                  Respondent.       *
*************************************

Clifford J. Shoemaker, Vienna, VA, for petitioner.

Debra A. Filteau Begley, United States Department of Justice, Washington, DC, for respondent.

                                   OPINION AND ORDER

SWEENEY, Judge

        Petitioner seeks compensation under the National Childhood Vaccine Injury Act of 1986
(“Vaccine Act”), 42 U.S.C. §§ 300aa-1 to -34 (2006), alleging that she sustained a spinal cord
stroke caused by a human papillomavirus (“HPV”) vaccination. In a September 28, 2013
decision, the special master denied petitioner’s request for compensation. Before the court is
petitioner’s motion for review of the special master’s decision. For the reasons set forth below,
the court denies petitioner’s motion for review and sustains the decision of the special master.




       1
          Vaccine Rule 18(b), contained in Appendix B of the Rules of the United States Court of
Federal Claims, affords each party fourteen days in which to object to the disclosure of (1) trade
secrets or commercial or financial information that is privileged or confidential or (2) medical
information that would constitute “a clearly unwarranted invasion of privacy.” Neither party
objected to the public disclosure of any information contained in this opinion.

                                               -1-
                                      I. BACKGROUND

                                      A. Medical History

        Petitioner’s medical history is not in dispute, and can be briefly summarized.2 On April
28, 2008, when she was fourteen years old, petitioner received her first HPV vaccination. She
received her second HPV vaccination on June 27, 2008. The following day, she began to
experience several symptoms, including left-sided weakness, severe headache, and shortness of
breath. She then developed flaccid paralysis of her extremities and slurred speech. When the
emergency medical service arrived at her house, petitioner developed bradycardia and suffered a
cardiac arrest. She was taken to the emergency room at Mt. Sinai Hospital, and was subsequently
transferred to Rush University Medical Center (“Rush”).

       At Rush, petitioner underwent an extensive medical workup and was given a working
diagnosis of transverse myelitis. That diagnosis changed after two neurologists, Drs. Tilwalli and
Stefofski, examined petitioner on August 6, 2008. As described by the special master:

       Dr. Tilwalli, a neurology fellow, opined that given Valeria’s quick onset, absence
       of inflammatory markers, and lack of response to anti-inflammatory treatment, he
       favored a vascular etiology. He also noted that he thought Valeria’s HPV
       vaccination was too close to symptom onset to induce an inflammatory response.
       Similarly, a neurologist, Dr. Stefofski, opined that Valeria’s quick symptom onset
       “strongly favors a vascular etiology over immune mediated/inflammatory
       (definitely too soon for Gardasil or even for a remote preceding myelitogenic
       trigger).” He also noted that due to the lack of response to corticosteroids and
       cyclophosphamide, he doubted an autoimmune etiology.

Flores, 2013 WL 5587390, at *4 (citations omitted). Ultimately, it was determined that
petitioner had experienced a spinal cord stroke.

       On August 7, 2008, petitioner was transferred from Rush to the Rehabilitation Institute of
Chicago. Her physical condition did not improve; she continued to require total assistance for
mobility and all activities of daily living. In addition, she had been on continuous ventilation
during her stay at Rush and remained on the ventilator during her rehabilitation. Petitioner was
discharged from inpatient rehabilitation on December 16, 2008. Since that time, she has shown
some improvement–she has begun to feel some sensation in her extremities and exhibited
voluntary movement in two fingers. However, she remains dependent on a ventilator.




       2
          The court derives petitioner’s undisputed medical history from the special master’s
decision. See generally Flores v. Sec’y of HHS, No. 10-489V, 2013 WL 5587390, at *3-5 (Fed.
Cl. Spec. Mstr. Sept. 12, 2013).

                                               -2-
                                     B. Procedural History

        Petitioner’s father filed a petition for compensation under the Vaccine Act on July 29,
2010, claiming that the HPV vaccine caused his daughter’s spinal cord stroke. Upon reaching
the age of majority, Ms. Flores was substituted as petitioner. After the submission of medical
records and expert reports, the special master convened an evidentiary hearing, during which he
heard the testimony of three expert witnesses. Petitioner offered the testimony of neurologist
Douglas A. Kerr, M.D., Ph.D., and respondent offered the testimony of pediatric neurologist
Peter M. Bingham, M.D., and pediatric hematologist Joan Cox Gill, M.D. Posthearing briefs
were filed, and the special master issued a decision on September 12, 2013.

         In his decision, the special master noted that all three experts agreed that petitioner had
suffered a spinal cord stroke, which was caused by a blood clot that had become lodged in a
spinal cord vessel, depriving petitioner’s spinal cord of oxygen and causing permanent injury.
Where the experts disagreed, the special master explained, was on the cause of the blood clot.
Dr. Kerr opined that the blood clot was caused by the HPV vaccine. Specifically, he asserted that
petitioner had a genetic predisposition to blood clotting involving multiple genes; that
petitioner’s first HPV vaccination sensitized her immune system; that the second HPV
vaccination elicited an exuberant, rapid immune response; and that the immune response resulted
in petitioner’s blood clot, either through inflammation or platelet aggregation. Drs. Bingham and
Gill, on the other hand, found it improbable that the HPV vaccine could be connected to
petitioner’s blood clot. Dr. Bingham explained that there was neither clinical evidence of
inflammation, nor a noted connection between the HPV vaccine and spinal cord strokes or blood
clots. Dr. Gill asserted that there was no clinical evidence of inflammation or platelet
aggregation, and that a clotting response via inflammation would have taken at least four days to
develop.

        The special master initially found that petitioner was unable to establish that she had a
genetic predisposition to blood clotting. Because this genetic predisposition was a critical factor
of the theory of causation advanced by Dr. Kerr, the special master concluded that petitioner
could not establish that Dr. Kerr’s theory was probable. Although this conclusion, on its own,
was sufficient to deny petitioner’s request for compensation under the Vaccine Act, the special
master addressed other aspects of Dr. Kerr’s theory. First, he noted that Dr. Kerr’s theory was
premised on petitioner’s spinal cord stroke originating from a blood clot in a vein (venous
thrombosis), but that the evidence supported a finding that the blood clot originated in an artery
(arterial thrombosis). Second, the special master held that petitioner failed to demonstrate that
the HPV vaccine can contribute to the type of inflammation that causes blood clots and strokes or
that petitioner’s second HPV vaccination did contribute to her blood clot or stroke. Similarly,
the special master concluded that petitioner had not shown that she had experienced platelet
aggregation or that any platelet aggregation contributed to her blood clot or stroke.

       In addition to addressing specific elements of Dr. Kerr’s theory of causation, the special
master discussed some of the medical literature submitted by the parties. He held that the Slade


                                                -3-
article, relied upon heavily by Dr. Kerr, did not offer “significant support” for the proposition
that the HPV vaccine can contribute to strokes. The special master also concluded that other
medical literature added “slightly” to the reasons to reject Dr. Kerr’s theories of causation.

        At the close of his decision, after concluding that the lack of an identifiable cause of
petitioner’s spinal cord stroke did not offer “significant support” for her theory that the HPV
vaccine caused the stroke, the special master analyzed petitioner’s case under the test for
causation set forth in Althen v. Secretary of HHS, 418 F.3d 1274 (Fed. Cir. 2005). In Althen, the
United States Court of Appeals for the Federal Circuit (“Federal Circuit”) articulated a three-part
test, based on prior precedent, explaining what a petitioner must show to prove causation under
the Vaccine Act:

       [Petitioner]’s burden is to show by preponderant evidence that the vaccination
       brought about [the] injury by providing: (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 showing of a
       proximate temporal relationship between vaccination and injury.

Id. at 1278. The special master concluded that petitioner had not established either of the first
two prongs of the Althen test, explaining that petitioner had not shown, more probably than not,
that the HPV vaccine could contribute to spinal cord strokes or that the HPV vaccination
petitioner received on June 27, 2008, did cause her stroke. The special master also noted that the
timing of petitioner’s stroke was evidence that it was not caused by the HPV vaccine.
Remarking that this was not a close case, the special master held that petitioner had not met her
burden of proving that the HPV vaccine caused her stroke. He therefore denied petitioner’s
request for compensation. Petitioner, alleging error, seeks review of the special master’s
decision, which respondent opposes. The court heard argument on the parties’ competing
positions on February 26, 2014.3

                                        II. DISCUSSION

       The United States Court of Federal Claims has jurisdiction to review the record of the
proceedings before a special master, and upon such review, may:

       (A) uphold the findings of fact and conclusions of law of the special master and
       sustain the special master’s decision,


       3
          During the February 26, 2014 proceedings, petitioner advanced several arguments that
were not raised in her motion for review. These arguments are waived and the court will not
address them. See L-3 Commc’ns EOTech, Inc. v. United States, 87 Fed. Cl. 656, 659 n.2
(2009) (“Plaintiff must not be allowed to advance new legal theories at oral argument,
prejudicing defendant.”); see also SmithKline Beecham Corp. v. Apotex Corp., 439 F.3d 1312,
1319 (Fed. Cir. 2006) (“[A]rguments not raised on the opening brief are waived.”).

                                                 -4-
       (B) 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

       (C) remand the petition to the special master for further action in accordance with
       the court’s direction.

42 U.S.C. § 300aa-12(e)(2). In the instant case, petitioner enumerates, pursuant to Vaccine Rule
24, three objections to the special master’s decision. First, petitioner asserts that the special
master impermissibly required her to identify the specific genes or cluster of genes that could
have caused her susceptibility to blood clotting. Second, petitioner contends that the special
master abused his discretion by rejecting several aspects of Dr. Kerr’s testimony regarding the
logical sequence of cause and effect that connected her second HPV vaccination to her spinal
cord stroke. Third, petitioner avers that the special master held her to an elevated burden of
proof that was rejected in Althen and was therefore not in accordance with the law. All three
objections relate to whether the special master properly held that petitioner had not established
that the HPV vaccine caused her spinal cord stroke.

                         A. Proving Causation Under the Vaccine Act

        Pursuant to 42 U.S.C. § 300aa-13(a)(1), the court shall award compensation if a petitioner
proves, by a preponderance of evidence, all of the elements set forth in 42 U.S.C. § 300aa-
11(c)(1),4 and if there is not a preponderance of evidence that the illness is due to factors
unrelated to the administration of the vaccine. A petitioner can recover in one of two ways:
either by proving an injury listed on the Table or by proving causation-in-fact. See 42 U.S.C.
§§ 300aa-11(c)(1)(C), -13(a)(1). Under the first method of recovery, a petitioner must
demonstrate that the injury was sustained within the time frame set forth in the Table. Id.
§ 300aa-11(c)(1)(C)(I), -14(a). “If petitioner can make such a showing, causation is presumed
and petitioner is deemed to have made out a prima facie case of entitlement to compensation
under the Act.” Whitecotton v. Sec’y of HHS, 81 F.3d 1099, 1102 (Fed. Cir. 1996).

        To establish a prima facie case when proceeding on a causation-in-fact theory, as
petitioner attempted to do in this case, a petitioner must “prove, by a preponderance of the


       4
           Subsection (c)(1) requires, among other things, that the following elements be satisfied:
(1) that the vaccine in question is set forth in the Vaccine Injury Table (“Table”); (2) that the
vaccine was received in the United States or in its trust territories; (3) that the injured person
either sustained an injury as a result of the administration of a Table-designated vaccine for a
period of more than six months after the administration of the vaccine, suffered illness, disability,
injury, or condition from the vaccine that resulted in inpatient hospitalization and surgical
intervention, or died from the administration of the vaccine; and (4) that the petitioner has not
previously collected an award or settlement of a civil action for damages arising from the alleged
vaccine-related injury or death. 42 U.S.C. § 300aa-11(c)(1).

                                                 -5-
evidence, that the vaccine was not only a but-for cause of the injury but also a substantial factor
in bringing about the injury.” Shyface v. Sec’y of HHS, 165 F.3d 1344, 1352 (Fed. Cir. 1999).
“[T]o show that the vaccine was a substantial factor in bringing about the injury, the petitioner
must show ‘a medical theory causally connecting the vaccination and the injury.’” Id. at 1352-53
(quoting Grant v. Sec’y of HHS, 956 F.2d 1144, 1148 (Fed. Cir. 1992) (per curiam)). In other
words, “[t]here must be a ‘logical sequence of cause and effect showing that the vaccination was
the reason for the injury,’” id. at 1353 (quoting Grant, 956 F.2d at 1148), and “[t]his ‘logical
sequence of cause and effect’ must be supported by a sound and reliable medical or scientific
explanation,” Knudsen v. Sec’y of HHS, 35 F.3d 543, 548 (Fed. Cir. 1994) (citing Daubert v.
Merrell Dow Pharms., Inc., 509 U.S. 579 (1993); Jay v. Sec’y of HHS, 998 F.2d 979, 984 (Fed.
Cir. 1993)); see also 42 U.S.C. § 300aa-13(a)(1) (“The special master or court may not make
such a finding based on the claims of a petitioner alone, unsubstantiated by medical records or by
medical opinion.”). However, medical or scientific certainty is not required. Knudsen, 35 F.3d
at 548-49; Bunting v. Sec’y of HHS, 931 F.2d 867, 873 (Fed. Cir. 1991).

        As noted above, the Federal Circuit, in Althen, distilled this prior precedent into a three-
part test, holding that to prove causation-in-fact, a petitioner must provide “(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 showing of a proximate
temporal relationship between vaccination and injury.” 418 F.3d at 1278. All three prongs
“must cumulatively show that the vaccination was a ‘but-for’ cause of the harm, rather than just
an insubstantial contributor in, or one among several possible causes of, the harm.” Pafford v.
Sec’y of HHS, 451 F.3d 1352, 1355 (Fed. Cir. 2006).

        Once a petitioner has established a prima facie case, the burden shifts to the respondent to
show, by a preponderance of the evidence, that the injury was caused by a factor unrelated to the
vaccine. 42 U.S.C. § 300aa-13(a)(1)(B); Shalala v. Whitecotton, 514 U.S. 268, 270-71 (1995);
de Bazan v. Sec’y of HHS, 539 F.3d 1347, 1352 (Fed. Cir. 2008). However, if a petitioner fails
to establish a prima facie case, the burden does not shift. Bradley v. Sec’y of HHS, 991 F.2d
1570, 1575 (Fed. Cir. 1993). Regardless of whether the burden ever shifts to the respondent, the
special master may consider the evidence presented by the respondent in determining whether the
petitioner has established a prima facie case. See Stone v. Sec’y of HHS, 676 F.3d 1373, 1379
(Fed. Cir. 2012) (“[E]vidence of other possible sources of injury can be relevant not only to the
‘factors unrelated’ defense, but also to whether a prima facie showing has been made that the
vaccine was a substantial factor in causing the injury in question.”); de Bazan, 539 F.3d at 1353
(“The government, like any defendant, is permitted to offer evidence to demonstrate the
inadequacy of the petitioner’s evidence on a requisite element of the petitioner’s case-in-chief.”).

  B. Allegations That Portions of the Special Master’s Decision Were Not in Accordance
                                      With the Law

        Within her enumerated objections to the special master’s decision, petitioner contends
that several of the special master’s conclusions were not in accordance with the law.


                                                 -6-
Specifically, she argues that the special master, in various portions of his decision, required her
to provide “objective confirmation in the medical community” linking her second HPV
vaccination to her spinal cord stroke, impermissibly elevating her burden beyond what is
permitted by the Vaccine Act. Mot. 16.

                                     1. Genetic Susceptibility

         Petitioner first asserts that the special master improperly elevated her burden of proof by
requiring her to identify the specific genes or cluster of genes that made her susceptible to a
vaccine injury. In his decision, the special master noted that Dr. Kerr’s theory of causation
depended on petitioner being genetically susceptible to blood clotting, and that Dr. Kerr testified
that such a genetic predisposition would involve a combination of several genes. However, Dr.
Kerr was unable to identify what genes or gene combination would be involved. In addition, Dr.
Kerr acknowledged that a gene mutation discovered during petitioner’s workup at Rush–a
MTHFRA1298C heterozygous mutation–could not, by itself, cause susceptibility to blood
clotting or stroke, and that the MTHFR gene might not have been part of the gene cluster at all.
Indeed, remarked the special master, Dr. Gill, a hematologist, explained that petitioner’s MTHFR
gene mutation does not cause blood clotting, and that there was no clinical evidence of petitioner
having other MTHFR gene mutations that might increase the risk of blood clots. Based on all of
this testimony, the special master concluded that Dr. Kerr’s assertion that petitioner must have
had a cluster of genes causing a predisposition to blood clotting was no more than mere
speculation, and was therefore insufficient to meet petitioner’s burden of establishing a probable
theory of causation.

         A close examination of the special master’s analysis reveals that he did require petitioner
to offer proof of the specific genes or gene cluster that contributed to petitioner’s predisposition
to blood clotting. See, e.g., Flores, 2013 WL 5587390, at *8 (“Dr. Kerr acknowledged that he
did not know what that combination of genes might be. In the final analysis, I conclude that Dr.
Kerr was engaging in mere speculation or guesswork in concluding that Valeria must have had
such a cluster of genes. Thus, this part of his theory . . . has not been shown to be probable.”
(citation omitted)), *9 (“I find that Dr. Kerr totally failed to establish . . . that Valeria had some
type of genetic predisposition that made her susceptible to have blood clots. . . . [H]e could do
no more than propose that Valeria might have had a cluster of several different genes that made
her susceptible, but could not even propose what any of those genes might have been.”). The
special master was incorrect to do so.

        Under the second prong of the Althen test, petitioner must show a logical sequence of
cause and effect connecting her second HPV vaccination to her spinal cord stroke. In making
this showing, she cannot be required to prove “the presence of . . . genetic disposition” because
such a requirement is “inconsistent with allowing ‘the use of circumstantial evidence envisioned
by the preponderance standard’” and therefore “impermissibly raises [her] burden under the
Vaccine Act . . . .” Capizzano v. Sec’y of HHS, 440 F.3d 1317, 1325 (Fed. Cir. 2006) (quoting
Althen, 418 F.3d at 1280). Thus, while direct evidence of genetic susceptibility is probative, in


                                                 -7-
the absence of such direct evidence, petitioner was entitled to demonstrate genetic susceptibility
through medical opinion. Id. at 1326. Therefore, requiring petitioner to identify the specific
genes or gene cluster that contributed to her purported blood clotting predisposition is contrary to
law. Nevertheless, this error is not dispositive. As the court explains later in this decision,
because the special master correctly concluded that petitioner failed to establish other aspects of
the causation theory advanced by Dr. Kerr, she cannot demonstrate entitlement to compensation
under the Vaccine Act.

                                      2. Medical Literature

         Another portion of the special master’s decision that was contrary to law, asserts
petitioner, is the special master’s review of and reliance on medical literature. Specifically, she
contends that although the special master stated that he was not requiring her to submit medical
literature, he improperly used the submitted medical literature showing that there was no
association between the HPV vaccine and her injury to “bolster the weight of evidence” against
her. Mot. 15. According to petitioner, this practice was rejected by the Federal Circuit in Althen
and Capizzano. Upon reviewing the special master’s decision, however, the court discerns no
error.

        In Althen and Capizzano, the Federal Circuit merely held that a special master could not
require a petitioner to submit medical literature to prove causation. Capizzano, 440 F.3d at 1324;
Althen, 418 F.3d at 1280. In neither case did the Federal Circuit preclude, much less discuss, a
special master’s review and use of medical literature submitted by the parties on their own
volition. In fact, in Andreu v. Secretary of HHS, the Federal Circuit remarked:

              Although Althen and Capizzano make clear that a claimant need not
       produce medical literature or epidemiological evidence to establish causation
       under the Vaccine Act, where such evidence is submitted, the special master can
       consider it in reaching an informed judgment as to whether a particular
       vaccination likely caused a particular injury. Althen makes clear that a claimant’s
       theory of causation must be supported by a “reputable medical or scientific
       explanation.” The assessment of whether a proffered theory of causation is
       “reputable” can involve assessment of the relevant scientific data.

569 F.3d 1367, 1379-80 (Fed. Cir. 2009) (citations omitted). In his decision, the special master
thoroughly evaluated the Slade article, which was submitted by both parties in support of their
respective positions, and concluded that it did not provide “significant support for Dr. Kerr’s
general proposition that the HPV vaccine [could] contribute to causing strokes.” Flores, 2013
WL 5587390, at *13-15. The special master then addressed other medical literature in the
record–specifically the Gold and Gee articles–and determined that it “add[ed] slightly to the
reasons for rejecting Dr. Kerr’s causation theory.” Id. at *16. There is no indication that the
special master required petitioner to provide medical literature supporting Dr. Kerr’s causation
theory; indeed, the special master clearly recognized that medical literature or epidemiological


                                                -8-
evidence was not required to prove causation. Thus, under binding Federal Circuit precedent, it
was not legally improper for the special master to consider the articles submitted by the parties
and determine whether they supported or detracted from the theory of causation advanced by Dr.
Kerr.

                          3. Unknown Etiology of Petitioner’s Injury

        The third portion of the special master’s decision challenged by petitioner as contrary to
law is the special master’s discussion of the lack of evidence supporting an alternative cause for
her injury. Petitioner contends that this lack of evidence is only relevant to respondent’s burden
of establishing an alternative cause, and not to Dr. Kerr’s theory of causation. Petitioner is
mistaken.

        As noted above, a special master may consider the existence of alternative causes of
injury in determining whether the petitioner has established a prima facie case of causation. See
Stone, 676 F.3d at 1379; de Bazan, 539 F.3d at 1353. Here, the special master noted that neither
the medical records, nor respondent’s experts, identified a known cause of petitioner’s spinal
cord stroke. He therefore inquired whether the lack of evidence of a known cause supported Dr.
Kerr’s theory that petitioner’s second HPV vaccination caused her stroke. Upon reviewing the
evidence in the record, the special master concluded that because it was “common for the cause
of spinal cord strokes not to be identified,” the fact that the cause of petitioner’s stroke was not
identified did not make Dr. Kerr’s theory more tenable. Flores, 2013 WL 5587390, at *17. As
the unambiguous Federal Circuit precedent makes clear, the special master did not err in
considering evidence related to an alternative cause in determining whether petitioner had met
her burden of proof of causation.

                C. Allegations That the Special Master Abused His Discretion

        In addition to arguing that parts of the special master’s decision were contrary to law,
petitioner contends that the special master abused his discretion in rejecting Dr. Kerr’s testimony
regarding certain elements of the logical sequence of cause and effect that allegedly connected
her second HPV vaccination to her spinal cord stroke; namely, the origin of her blood clot and
the existence of inflammation and platelet aggregation. An abuse of discretion occurs when a
“decision is based on clearly erroneous findings of fact, is based on erroneous interpretations of
the law, or is clearly unreasonable, arbitrary or fanciful.” Cybor Corp. v. FAS Techs., Inc., 138
F.3d 1448, 1460 (Fed. Cir. 1998) (en banc); accord Hendler v. United States, 952 F.2d 1364,
1380 (Fed. Cir. 1991) (“An abuse of discretion may be found when (1) the court’s decision is
clearly unreasonable, arbitrary, or fanciful; (2) the decision is based on an erroneous conclusion
of the law; (3) the court’s findings are clearly erroneous; or (4) the record contains no evidence
upon which the court rationally could have based its decision.”), quoted in Murphy v. Sec’y of
HHS, 30 Fed. Cl. 60, 61 (1993). It is well settled that under this standard, the court accords




                                                -9-
deference to the special master’s factual findings and fact-based conclusions.5 It is not the
court’s role to reweigh the evidence. See Hodges v. Sec’y of HHS, 9 F.3d 958, 961 (Fed. Cir.
1993) (“[O]n review, the Court of Federal Claims is not to second guess the Special Master[’]s
fact-intensive conclusions; the standard of review is uniquely deferential for what is essentially a
judicial process. . . . That level of deference is especially apt in a case in which the medical
evidence of causation is in dispute.”). Despite this unambiguous standard, a review of
petitioner’s contentions reveals that this is precisely what petitioner is asking the court to
do–reweigh the evidence.

                            1. The Origin of Petitioner’s Blood Clot

        Petitioner first contends that the special master abused his discretion by rejecting Dr.
Kerr’s testimony that her spinal cord stroke originated from a venous thrombosis in favor of Dr.
Gill’s testimony that her stroke originated from an arterial thrombosis. In support of this
contention, petitioner notes that Dr. Kerr has more experience than Dr. Gill with spinal cord
strokes and avers that Dr. Gill relied on the results of a test–the D-dimer test–that do not support
her position. Accordingly, petitioner argues, the special master’s conclusion that Dr. Gill was
more persuasive on the origin of the blood clot was improper.

        While petitioner’s first point–that Dr. Kerr was more experienced than Dr. Gill regarding
spinal cord strokes–may be true, it is only one aspect of what the special master could have
considered in analyzing the origins of petitioner’s blood clot. Indeed, the special master’s
decision reflects that he considered the testimony of all three experts regarding the bases for their
respective positions, as well as a medical article that supported Dr. Gill’s position. That the
special master assigned different weights to this evidence than the weights preferred by petitioner
is not an abuse of discretion.

        Petitioner’s second point concerns the results of three D-dimer tests she underwent at
Rush on July 5 and 6, 2008. According to the undisputed testimony of Dr. Gill, the D-dimer test
shows whether there is ongoing coagulation, and a negative result suggests that a venous
thrombosis is highly unlikely. The reference range for petitioner’s D-dimer tests was “0.00 -
0.60 ug/mL,” and appended to the results of each test was the following comment: “D-Dimer
results of less than 0.5 ug/mL have been shown to contribute to the exclusion of venous


       5
          There is abundant precedent from the Federal Circuit to this effect. See, e.g.,
Whitecotton, 81 F.3d at 1108 (“Congress desired the special masters to have very wide discretion
with respect to the evidence they would consider and the weight to be assigned that evidence.”);
Munn v. Sec’y of HHS, 970 F.2d 863, 871 (Fed. Cir. 1992) (emphasizing that “the probative
value of the evidence” and “the credibility of the witnesses” were within the special master’s
purview as fact finder); Hines v. Sec’y of HHS, 940 F.2d 1518, 1527 (Fed. Cir. 1991)
(“[A]rguments as to the weighing of evidence, particularly where, as here, witness credibility is
involved, do not demonstrate reversible error.”).


                                                -10-
thromboembolism with a negative predictive value of approximately 98% when results are used
as part of the total clinical evaluation of the patient.” Pet’r’s Ex. 20 at 928-32. The results of
petitioner’s three D-dimer tests were 0.51 ug/mL, 0.46 ug/mL, and 0.49 ug/mL. Id. Dr. Gill
testified that these test results made it “very unlikely” that petitioner suffered from a venous
thrombosis. Tr. 164.

        Petitioner advances two arguments related to the D-dimer test results: (1) Dr. Gill’s
testimony was contradicted by the comment in the test results, and (2) Dr. Gill acknowledged
that petitioner was taking medication that could lower the test results. Petitioner’s first argument
suffers from an error in logic. Petitioner contends that the 0.51 ug/mL test result contradicts Dr.
Gill’s testimony because it does not meet the “less than 0.5 ug/mL” threshold described in the
test result comment.6 However, the fact that test results that are less than 0.5 ug/mL may help
exclude the existence of a venous thrombosis with 98% certainty does not mean that test results
that are greater than 0.5 ug/mL reflect the existence of a venous thrombosis. Rather, the more
logical conclusion is that a test result that is greater than 0.5 ug/mL, but still within the reference
range, may help exclude the existence of a venous thrombosis, but with less than 98% certainty.
This interpretation is supported by Dr. Gill’s characterization of petitioner’s D-dimer test results
as “negative,” id., and “within the normal range,” id. at 182-84. Thus, the comment in the D-
dimer test results does not contradict Dr. Gill’s testimony as petitioner contends.

        Petitioner’s second argument fares no better. While Dr. Gill acknowledged that one of
petitioner’s medications could lower the D-dimer test results, she did not retract her conclusion
that the test results made a venous thrombosis unlikely. As a result, the record contains evidence
that supports the special master’s reliance on Dr. Gill’s analysis of the D-dimer test results.
Petitioner therefore has not demonstrated that the special master’s acceptance of Dr. Gill’s
testimony was an abuse of discretion. Instead, all that she has established is that she would
weigh the evidence regarding the effect of petitioner’s medication on the D-dimer test results
differently.

       In sum, the special master’s conclusion that Dr. Gill was more persuasive than Dr. Kerr
regarding the origin of petitioner’s blood clot was not improper.

                            2. Inflammation and Platelet Aggregation

        In addition to arguing that the special master should not have rejected Dr. Kerr’s
testimony that she experienced a venous thrombosis, petitioner contends that the special master
abused his discretion in rejecting Dr. Kerr’s testimony regarding how the immune response
triggered by her second HPV vaccination led to a blood clot, and instead accepting the testimony
of Dr. Gill.




       6
           Petitioner does not address the other two D-dimer test results in her motion for review.

                                                 -11-
        Dr. Kerr proposed two mechanisms that might link petitioner’s immune response to her
blood clot: inflammation and platelet aggregation. With respect to inflammation, petitioner
asserts that Dr. Kerr’s theory relied upon the presence of localized inflammation, i.e.,
inflammation in her central nervous system, and that Dr. Gill rejected Dr. Kerr’s theory because
(1) there was no evidence of systemic inflammation in her test results and (2) her spinal cord
stroke occurred too soon after her second HPV vaccination. Petitioner contends that the special
master’s acceptance of Dr. Gill’s testimony over the testimony of Dr. Kerr was improper because
Dr. Gill was looking for systemic inflammation based on an incorrect diagnosis of her
neurological injury, and because the timing of her stroke was appropriate because her immune
system was primed by her first HPV vaccination. She further contends, with respect to platelet
aggregation, that the special master improperly required her to prove a specific biological
mechanism of injury.7

        Ultimately, Dr. Gill’s characterization of petitioner’s injury and the possible priming
effect of petitioner’s first HPV vaccination were not material to the special master’s decision to
reject Dr. Kerr’s testimony. Not only did Dr. Gill and Dr. Bingham testify that none of
petitioner’s test results reflected systemic inflammation, Dr. Bingham further testified that the
results of tests of petitioner’s spinal cord fluid did not show inflammation, i.e., there was no
evidence of localized inflammation. Moreover, Dr. Gill testified that there was no evidence of
platelet aggregation in petitioner’s test results. The special master was therefore entitled to
conclude that if the logical sequence of cause and effect posited by Dr. Kerr included the
existence of inflammation or platelet aggregation, but there was no evidence of inflammation or
platelet aggregation in any of petitioner’s test results, then petitioner could not establish an
essential element of causation linking her second HPV vaccination to her spinal cord stroke.

         The court’s conclusion finds ample support in Federal Circuit precedent. See, e.g.,
Moberly v. Sec’y of HHS, 592 F.3d 1315, 1324 (Fed. Cir. 2010) (noting that “the special master
is entitled to require some indicia of reliability to support the assertion of the expert witness” and
holding that the special master did not err in rejecting the petitioner’s theory of causation when
petitioner’s expert could not identify any evidence that the mechanism underlying his theory was
at work in the petitioner’s case); see also Capizzano, 440 F.3d at 1327 (“A claimant could satisfy
the first and third prongs [of the Althen test] without satisfying the second prong when medical
records and medical opinion do not suggest that the vaccine caused the injury . . . .”). The
Federal Circuit’s decision in Stone is particularly instructive. In that case, the injured children
suffered from Severe Myoclonic Epilepsy of Infancy, a seizure disorder. Stone, 676 F.3d at
1374. The theory of causation proposed by the petitioners’ expert was that the vaccine at issue
caused a fever, triggering initial febrile seizures, which caused lasting brain injury, leading to the
seizure disorder. Id. at 1376, 1384. The special master concluded that there was no evidence
that the children suffered brain damage as a result of the initial seizures. Id. at 1384. In rejecting
the petitioners’ argument that the special master improperly required them to prove a biological


       7
        Petitioner did not raise this argument with respect to Dr. Kerr’s proposed mechanism of
inflammation.

                                                 -12-
mechanism of causation, the Federal Circuit remarked: “[T]he special master did not insist on
evidence of the biological mechanism by which the brain damage was caused. He merely sought
evidence of the existence of brain damage–a key component of [the expert’s] theory–and [the
expert] was unable to provide any.” Id. at 1385. Noting that the special master concluded that
the expert’s “inference of brain damage, in the face of clinical records showing no brain damage,
was unpersuasive and . . . therefore insufficient to carry the petitioners’ burden on causation,” the
Federal Circuit explained that the special master had “denied compensation not because the
parties failed to show how the vaccines caused brain damage, but because they failed to show
that the vaccines caused any brain damage.” Id. at 1384. Similarly here, the special master
denied petitioner compensation because she failed to show that her second HPV vaccination
actually did lead to a blood clot, either through inflammation or platelet aggregation. This was
not an abuse of discretion.

                                D. Application of the Althen Test

        The theory of causation advanced by Dr. Kerr was that petitioner had a genetic
predisposition to blood clotting involving multiple genes; that petitioner’s first HPV vaccination
sensitized her immune system; that the second HPV vaccination elicited an exuberant, rapid
immune response; that the immune response resulted in the blood clot, either through the
creation of inflammation or platelet aggregation; and that the blood clot caused petitioner’s spinal
cord stroke. To establish the second prong of the Althen test–a logical sequence of cause and
effect connecting the vaccine to the injury–petitioner was required to demonstrate each link in
this causative chain by a preponderance of the evidence. 42 U.S.C. § 300aa-13(a)(1). The court
concluded that the special master improperly required petitioner to provide specific proof of
genetic susceptibility to blood clotting. However, the special master’s rejection of Dr. Kerr’s
testimony regarding inflammation and platelet aggregation, which the court concluded was not an
abuse of discretion, leads the court to find that petitioner was unable to establish another link in
the causative chain–the link between the immune response triggered by her second HPV
vaccination and her blood clot. Thus, the special master’s determination that petitioner was not
entitled to compensation under the Vaccine Act because she did not establish that the HPV
vaccine caused her spinal cord stroke must be upheld.

                                       III. CONCLUSION

       For the reasons stated above, the court DENIES petitioner’s motion for review and
SUSTAINS the decision of the special master. The clerk is directed to enter judgment
accordingly.

       IT IS SO ORDERED.

                                                       s/ Margaret M. Sweeney
                                                       MARGARET M. SWEENEY
                                                       Judge


                                                -13-
