United States Court of Appeals for the Federal Circuit 

 2009-5128 

 ROLF HAZLEHURST and ANGELA HAZLEHURST, 

parents of WILLIAM YATES HAZLEHURST, 

Petitioners-Appellants, 

v. 

SECRETARY OF HEALTH AND HUMAN SERVICES, 

Respondent-Appellee. 

Curtis R. Webb, Webb, Webb & Guerry, of Twin Falls, Idaho, argued for petitionersappellants. 

Lynn E. Ricciardella, Trial Attorney, Torts Branch, Civil Division, United States 

Department of Justice, of Washington, DC, argued for respondent-appellee. With her on 

the brief were Tony West, Assistant Attorney General, Timothy P. Garren, Director, Mark 

W. Rogers, Deputy Director, and Gabrielle M. Fielding, Assistant Director. 

Appealed from: United States Court of Federal Claims 

Senior Judge John P. Wiese 
United States Court of Appeals for the Federal Circuit 

2009-5128 

ROLF HAZLEHURST and ANGELA HAZLEHURST, 

parents of WILLIAM YATES HAZLEHURST, 

Petitioners-Appellants, 

v. 

SECRETARY OF HEALTH AND HUMAN SERVICES, 

Respondent-Appellee. 

Appeal from the United States Court of Federal Claims 

in 03-VV-654, Senior Judge John P. Wiese. 

___________________________ 

DECIDED: May 13, 2010 

___________________________ 

Before NEWMAN and BRYSON, Circuit Judges, and GUILFORD, District Judge.

∗

BRYSON, Circuit Judge. 

This is one of a large number of cases involving claims for compensation on 

behalf of autistic children whose condition is alleged to have been caused by childhood 

vaccinations. In this case, Rolf and Angela Hazlehurst filed a claim for their son, Yates 

Hazlehurst, seeking compensation under the National Childhood Vaccine Injury Act of 

1986 (“the Vaccine Act”), 42 U.S.C. §§ 300aa-1 to -34. The Hazlehursts alleged that 

the measles, mumps, and rubella (“MMR”) vaccine, which was administered to Yates 

 

∗

 The Honorable Andrew J. Guilford, District Judge, United States District 

Court for the Central District of California, sitting by designation. 
2009-5128 2 

shortly before his first birthday, caused him to develop regressive autism. A special 

master denied the Hazlehursts’ petition, and the Court of Federal Claims affirmed. 

Hazlehurst v. Sec’y of Heath & Human Servs., 88 Fed. Cl. 473 (2009). On appeal to 

this court, the Hazlehursts argue that the special master improperly relied on certain 

evidence that should have been excluded and disregarded other evidence that should 

have been considered. We affirm. 

I 

 The Office of Special Masters consolidated this case with several others as part 

of what was termed the Omnibus Autism Proceeding, an effort by the Office of Special 

Masters to identify and adjudicate certain test cases as a means of addressing the 

principal issues in approximately 5,000 autism claims that have been filed under the 

Vaccine Act. The objective of the omnibus proceeding was to determine the 

relationship, if any, between vaccines and autism spectrum disorders. This case was 

considered together with two others, Cedillo v. Secretary of Health and Human 

Services, No. 98-916V, and Snyder v. Secretary of Health and Human Services, No. 01-

162V, in one of the groups of test cases. In the Cedillo and Snyder cases, the 

petitioners presented a theory of causation based on the combined effect of the MMR 

vaccine and vaccines containing thimerosal, a vaccine preservative. The Hazlehursts 

initially presented that theory of causation, but in post-hearing briefing they relied on the 

theory that Yates’s autism was caused by the MMR vaccine alone. Although each of 

the three cases was decided by a different special master, the record in this case 

includes all of the general causation evidence admitted in Cedillo and Snyder. The full 

record encompasses tens of thousands of pages of medical literature, more than four 
2009-5128 3 

thousand pages of hearing testimony, and fifty expert reports containing the opinions of 

seven experts for the petitioners and eighteen experts for the government. 

 The evidence at the hearing showed that Yates Hazlehurst was born on February 

11, 2000, and developed normally during his first year of life. On February 8, 2001, 

three days before his first birthday, Yates received an MMR vaccination. Within a 

month after his MMR vaccination, according to his family, Yates became “wild,” “very 

hyperactive,” and “out of control.” By the summer of 2001, Yates had lost all meaningful 

speech, even though he had previously used words such as “mama,” “please,” and 

“thank you.” At about the same time, he developed chronic diarrhea and abdominal 

pain. Following a series of evaluations in July 2002, Yates was diagnosed as exhibiting 

a pattern of behavior consistent with autism. 

 In 2003, the Hazlehursts filed a petition for vaccine injury compensation under 

the Vaccine Act. The special master summarized their theory of causation as follows: 

[P]etitioners assert that the measles component of the MMR vaccine 

causes an immune dysfunction that impairs the vaccinee’s ability to clear 

the measles virus. Unable to properly clear the measles virus from the 

body, the vaccinee experiences measles virus persistence which leads to 

chronic inflammation in the gastrointestinal system and, in turn, chronic 

inflammation in the brain. Petitioners argue that the inflammation in the 

brain causes neurological damage that manifests as autism. 

Hazlehurst v. Sec’y of Health & Human Servs., No. 03-654V, 2009 WL 332306, at *86 

(Fed. Cl. Feb. 12, 2009). The Hazlehursts acknowledged that the linchpin of their 

theory was the discovery of persistent measles virus in certain autistic children who had 

received the MMR vaccine. That evidence derived from the research of Dr. Andrew 

Wakefield of the Royal Free Hospital in London and his colleagues at the Unigenetics 
2009-5128 4 

laboratory in Dublin, and the research of Dr. Stephen Walker and his colleagues at the 

Wake Forest University School of Medicine. 

Dr. Wakefield was the primary proponent of the hypothesis that the MMR vaccine 

could cause autism in certain children. His work led to civil litigation against certain 

vaccine manufacturers in the United Kingdom (“the UK litigation”). The Unigenetics 

laboratory was a for-profit, non-accredited institution that was established to support the 

UK litigation by testing children for the presence of measles virus in certain body 

tissues. The Unigenetics research, which reported successful use of the polymerase 

chain reaction technique (“PCR”) to identify and amplify measles virus genetic material 

in the blood and intestinal tissues of autistic children, formed the basis for a 2002 article 

co-authored by Dr. Wakefield (the Uhlmann article) on which the Hazlehursts primarily 

rely. In addition, the Hazlehursts rely on preliminary research results reported by the 

Walker group. In an abstract and poster presentation delivered at the June 2006 

International Meeting for Autism Research (“IMFAR”), the Walker group claimed to have 

replicated the positive results reported by Unigenetics. 

 The Hazlehursts’ key witness at their hearing was Yates’s pediatric neurologist, 

Dr. Jean-Ronel Corbier. Dr. Corbier relied heavily on the results of the Unigenetics and 

Walker studies as support for his opinion that Yates’s February 8, 2001, MMR 

vaccination played a substantial role in causing Yates’s autism. Dr. Corbier testified 

that those studies suggested that the MMR vaccine may contribute to the development 

of regressive autism in children who fit a particular clinical profile, including normal 

development prior to receipt of the MMR vaccination, display of symptoms of regressive 
2009-5128 5 

autism within one to nine months after receipt of the MMR vaccination, and 

development of gastrointestinal problems during that period. 

The special master also heard testimony from Dr. Karin Hepner and Dr. Arthur 

Krigsman, two of the researchers in the Walker group. Drs. Hepner and Krigsman cited 

their own work as evidence of the reliability and reproducibility of the Unigenetics test 

results. They also stated that the Walker group had confirmed its results through 

genetic sequencing. Dr. Krigsman testified that the group had verified, at least for some 

samples, that the genetic material identified and amplified by PCR contained the same 

nucleotide sequence as the targeted product, i.e., vaccine-strain measles virus. 

In response to the petitioners’ evidence concerning the presence of measles 

virus in autistic children, the government offered expert testimony and reports from, 

among others, Dr. Stephen Bustin, a molecular biologist who had appeared as an 

expert in the UK litigation. In connection with the UK proceedings, Dr. Bustin had been 

hired by vaccine manufacturers to evaluate the testing methods of the Unigenetics 

laboratory. After analyzing Unigenetics’ equipment and notebooks, Dr. Bustin 

concluded that the Unigenetics researchers had failed to follow their own standard 

operating procedures, had failed to abide by certain standard laboratory practices, and 

had failed to comply with standards set forth by the manufacturers of the laboratory 

testing equipment, all of which undermined the reliability of the laboratory’s test results. 

Dr. Bustin memorialized his conclusions in reports that were filed under seal in the UK 

litigation and later released to the government in the Omnibus Autism Proceeding. 

Over objection, the government sought to introduce Dr. Bustin’s reports and 

testimony regarding the Unigenetics laboratory, which, by that time, had gone out of 
2009-5128 6 

business.1 The special master in the Cedillo case provisionally admitted the evidence. 

The three special masters in the omnibus proceeding then deferred decision on whether 

to rely on that evidence and stated that they would “favorably consider joining in a 

request” by the petitioners “for the release of relevant reports” from the UK litigation. 

The record remained open for more than a year following the Cedillo hearing to afford 

the petitioners sufficient time to present rebuttal evidence, to conduct additional crossexamination of Dr. Bustin, and to obtain documents from the British court. However, 

none of the petitioners recalled Dr. Bustin for further questioning or applied for access to 

any of the materials from the UK litigation. 

The special master subsequently denied the Hazlehursts’ motion to strike Dr. 

Bustin’s reports and testimony. She explained that Dr. Bustin’s evidence was highly 

relevant and that fairness had been achieved by affording the petitioners a generous 

period of time in which to obtain any additional relevant information. 

In her decision on the merits, the special master concluded that the Hazlehursts 

had failed to prove that Yates’s MMR vaccination had caused his autism. In a lengthy 

opinion, the special master analyzed the evidence of record in detail and addressed 

each aspect of the petitioners’ general and case-specific theories of causation. In 

particular, the special master found that the Wakefield, Unigenetics, and Walker studies 

were flawed or unreliable and that Dr. Corbier’s opinion regarding causation, which was 

largely predicated on those studies, was entitled to little weight. 

 

1

 The Unigenetics laboratory was closed following the discontinuation of the 

UK litigation. 
2009-5128 7 

The special master found that Dr. Wakefield’s work had been largely discredited 

within the scientific community and that none of the studies indicating the presence of 

measles virus in autistic children had been successfully replicated by an accredited 

laboratory independent of Dr. Wakefield or Unigenetics. In particular, the special 

master found that Dr. Wakefield’s early 1990s research on persistent measles infections 

was reviewed by the Medical Research Council of the United Kingdom and found to lack 

important controls and sufficiently specific reagents for detecting measles virus. She 

also found that Dr. Wakefield’s subsequent research was dismissed by the scientific 

community as methodologically unsound. In that regard, she noted that 10 of 12 coauthors on Dr. Wakefield’s controversial 1998 article in the medical journal The Lancet

subsequently retracted their support for the article’s conclusion that there is a potential 

causal link between the MMR vaccine and autism. 

Relying in part on Dr. Bustin’s testimony and reports, the special master also 

found that Unigenetics employed “flawed laboratory practices” that rendered its test 

results “scientifically unreliable.” She concluded that the laboratory practices at 

Unigenetics differed considerably not only from the standard practices for conducting 

PCR testing, but also from the operating procedures established within the laboratory. 

For example, the special master cited Dr. Bustin’s testimony that the Unigenetics 

researchers (1) tested degraded genetic material rather than discarding it; (2) used 

inconsistent procedures to extract and evaluate the genetic material; (3) omitted key 

steps necessary to prepare samples for PCR amplification; (4) failed to heed the 

equipment manufacturer’s instruction to exclude from analysis the first three cycles of 

amplification; and (5) reported positive findings, rather than re-running tests, when 
2009-5128 8 

duplicate assays showed inconsistent results (one positive and one negative). The 

special master also highlighted testimony suggesting the presence of contamination, 

including Dr. Bustin’s observation that approximately one-third of the test runs displayed 

positive results in the negative controls, which were specifically designed not to contain 

any of the targeted genetic material. 

The special master further concluded that the unpublished and preliminary 

findings of the Walker group should not be accorded significant weight. She observed 

that Dr. Hepner had declined to “draw any conclusions about the biological significance” 

of the investigators’ findings and had testified that negative controls were not included 

with each experimental run. The special master also noted that the petitioners’ experts 

based their opinions on the characteristics of the “wild-type” measles virus, as opposed 

to the vaccine-strain measles virus, which is far less virulent and replicates poorly in the 

human body. 

Based on all the evidence of record, the special master concluded that the 

Hazlehursts’ causation theory depended on evidence that was discredited, unreliable, or 

inapposite. The special master therefore denied the petition for compensation. The 

Hazlehursts then appealed to the Court of Federal Claims, which affirmed the special 

master’s decision in a comprehensive opinion. The Hazlehursts appealed that decision 

to this court. 

II 

The Hazlehursts argue that the special master improperly relied on Dr. Bustin’s 

testimony and reports criticizing the Unigenetics laboratory’s procedures, and that she 

failed to consider relevant evidence from Dr. Hepner indicating that the Walker group 
2009-5128 9 

had verified its test results through genetic sequencing. They urge that those errors 

require us to overturn the special master’s ultimate conclusion as to causation. 

We review de novo the judgment of the Court of Federal Claims reviewing a 

special master’s grant or denial of compensation under the Vaccine Act. Hines v. Sec’y 

of Health & Human Servs., 940 F.2d 1518, 1524 (Fed. Cir. 1991); see also Lampe v. 

Sec’y of Health & Human Servs., 219 F.3d 1357, 1360 (Fed. Cir. 2000). By statute, the 

Court of Federal Claims may set aside the special master’s decision “only if the special 

master’s fact findings are arbitrary and capricious, its legal conclusions are not in 

accordance with law, or its discretionary rulings are an abuse of discretion.” Turner v. 

Sec’y of Health & Human Servs., 268 F.3d 1334, 1337 (Fed. Cir. 2001), citing 42 U.S.C. 

§ 300aa-12(e)(2)(B). We apply the same standard when reviewing the judgment of the 

Court of Federal Claims. Id.

“[W]e do not sit to reweigh the evidence,” Lampe, 219 F.3d at 1363, or to make 

credibility determinations, which are “uniquely within the purview of the special master,” 

Burns v. Sec’y of Health & Human Servs., 3 F.3d 415, 417 (Fed. Cir. 1993). Our review 

pursuant to the Vaccine Act is “uniquely deferential”; we may not second-guess the 

special master’s fact-intensive conclusions, particularly where the medical evidence of 

causation is in dispute. Hodges v. Sec’y of Health & Human Servs., 9 F.3d 958, 961 

(Fed. Cir. 1993). If the special master has considered the relevant evidence of record, 

drawn plausible inferences, and articulated a rational basis for the decision, “reversible 

error will be extremely difficult to demonstrate.” Hines, 940 F.2d at 1528. 

Because Yates Hazlehurst’s injury is not on the Vaccine Injury Table, 42 U.S.C. § 

300aa-14, the Hazlehursts cannot avail themselves of the statutory presumption of 
2009-5128 10 

causation that applies to Table injuries. Moberly v. Sec’y of Health & Human Servs., 

592 F.3d 1315, 1321 (Fed. Cir. 2010). They were therefore required to demonstrate by 

a preponderance of the evidence that the MMR vaccine caused Yates’s condition. Id.

A 

 The Hazlehursts argue that the special master should have excluded Dr. Bustin’s 

testimony and reports criticizing Unigenetics’ laboratory practices. They contend that 

her consideration of that evidence violated the provision of the Vaccine Rules requiring 

evidentiary determinations to be governed by principles of fundamental fairness. 

According to the Hazlehursts, the admission of Dr. Bustin’s testimony and reports gave 

the government an unfair advantage because the petitioners could not adequately 

respond to Dr. Bustin’s criticisms without access to the materials he had examined, 

such as Unigenetics’ laboratory equipment and notebooks. Those materials are no 

longer in existence or are under seal following the closing of the Unigenetics laboratory 

and the termination of the UK litigation. In any event, the petitioners argue, it would 

have been prohibitively expensive for the petitioners to have their own experts review 

that evidence. 

 Vaccine Rule 8 provides that “[i]n receiving evidence, the special master will not 

be bound by common law or statutory rules of evidence but must consider all relevant 

and reliable evidence governed by principles of fundamental fairness to both parties.” 

Vaccine R. 8(b)(1) (2009). That rule echoes the statutory requirement that the special 

master “shall consider . . . all . . . relevant medical and scientific evidence.” 42 U.S.C. 

§ 300aa-13(b)(1). The rule, like the statute, directs the special master to consider all 

relevant and reliable evidence, unencumbered by traditional rules of admissibility, while 
2009-5128 11 

being guided by principles of fairness. We conclude that the special master complied 

with that directive when considering Dr. Bustin’s evidence. 

 The special master’s decision to admit and consider Dr. Bustin’s testimony and 

reports was in full accord with the principle of fundamental fairness. Although not 

obligated to do so, the petitioners chose to introduce the Unigenetics data and thus 

placed its validity squarely in issue. Fairness dictated that the government be given an 

opportunity to refute that critical evidence. See de Bazan v. Sec’y of Health & Human 

Servs., 539 F.3d 1347, 1353 (Fed. Cir. 2008) (“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.”); see also United States v. 

Nobles, 422 U.S. 225, 239-40 (1975) (party introducing evidence may not invoke 

attorney work-product doctrine to avoid challenges to that evidence). 

 As the special master noted, Dr. Bustin’s testimony and reports are highly 

relevant. They speak directly to the reliability of evidence central to the petitioners’ 

theory of causation: the detection of persistent measles virus in autistic children who 

received the MMR vaccine. As the Court of Federal Claims observed, once the 

petitioners introduced that evidence, “the special master was duty-bound to assess the 

reliability of those studies.” Hazlehurst, 88 Fed. Cl. at 483. Dr. Bustin’s evidence was 

directly pertinent to that assessment. Moreover, the special master determined that Dr. 

Bustin’s evidence was reliable. She found Dr. Bustin to be a credible witness and his 

testimony to be consistent with that of other witnesses for both parties regarding PCR 

testing and Unigenetics’ laboratory techniques. 
2009-5128 12 

We recognize, as did the trial court, that the unavailability of the Unigenetics 

equipment and records limited the Hazlehursts’ ability to respond to Dr. Bustin’s 

criticisms of the Unigenetics evidence. See Hazlehurst, 88 Fed. Cl. at 483-84. 

Nevertheless, probative evidence need not be excluded simply because circumstances 

make it difficult to challenge that evidence. See Payne v. Tennessee, 501 U.S. 808, 

823 (1991) (probative evidence not inadmissible because it would be difficult to rebut). 

Moreover, the special master appropriately sought to mitigate the difficulty presented by 

Dr. Bustin’s evidence by giving the petitioners more than a year in which to obtain 

additional information to counter Dr. Bustin’s analysis. See Hines, 940 F.2d at 1526 

(post-hearing taking of judicial notice of medical evidence did not violate “principles of 

fundamental fairness” where the petitioner was given a subsequent opportunity to rebut 

the evidence). The petitioners, however, chose not to seek relevant reports from the 

UK litigation or to recall Dr. Bustin for further questioning. 

The Hazlehursts also contend that the special master’s admission of Dr. Bustin’s 

testimony and reports violated the purpose of the Vaccine Act to resolve cases through 

simplified procedures without the trappings of “full blown tort litigation.” In keeping with 

that purpose, they assert that the special master should have excluded evidence such 

as Dr. Bustin’s elaborate and costly review of Unigenetics. 

It is correct that “[t]he Vaccine Act does not contemplate full blown tort litigation in 

the Court of Federal Claims.” Knudsen v. Sec’y of Health & Human Servs., 35 F.3d 

543, 549 (Fed. Cir. 1994). Rather, Congress intended for the Vaccine Act to establish a 

compensation system that is “fair, simple, and easy to administer.” Id., citing H.R. Rep. 

No. 99-908, at 7, as reprinted in 1986 U.S.C.C.A.N. 6344, 6348. In furtherance of that 
2009-5128 13 

purpose, Congress eliminated the usual requirement of proving fault and simplified the 

process of establishing causation. For Table injuries, causation is presumed, and even 

for off-Table injuries, proof of causation is simpler in certain respects than in tort 

litigation. See, e.g., id. (“[T]o require identification and proof of specific biological 

mechanisms would be inconsistent with the purpose and nature of the vaccine 

compensation program.”); Moberly, 592 F.3d at 1325 (“Nor is a petitioner required to 

point to epidemiological studies or ‘general acceptance in the scientific or medical 

communities’ to prove causation, as the legal standard is a preponderance of the 

evidence, not scientific certainty.”). 

Nothing in those underlying principles suggests that the special master’s 

consideration of Dr. Bustin’s evidence contravened the purposes of the Vaccine Act. 

The special master did not expect or require the Hazlehursts to replicate Dr. Bustin’s 

review of the Unigenetics laboratory procedures; rather, she offered the petitioners the 

opportunity to seek reports and exhibits that had been prepared for the UK litigation, just 

as the government had done. As the Court of Federal Claims observed, “given the fact 

that [the government] neither commissioned nor paid for [Dr. Bustin’s] reports, it is 

difficult to distinguish them conceptually from any information existing in the public 

domain.” Hazlehurst, 88 Fed. Cl. at 483 n.17. We therefore discern no legal error in the 

special master’s consideration of Dr. Bustin’s testimony and reports. 

In any event, we agree with the Court of Federal Claims that the special master 

would have reached the same conclusion regarding the reliability of the Unigenetics 

data even in the absence of Dr. Bustin’s evidence. The special master stated that she 

“d[id] not rely solely on [Dr. Bustin’s] testimony in evaluating the reliability of the test 
2009-5128 14 

results obtained by Unigenetics,” but also “consider[ed] the testimony of other witnesses 

and the filed scientific literature addressing Unigenetics’ testing techniques.” 

Hazlehurst, 2009 WL 332306, at *93. She discussed the testimony of the government’s 

witnesses Dr. Brian J. Ward (an infectious disease specialist), Dr. Diane Griffin (an 

immunologist), and Dr. Bertrus Rima (a virologist), and found it to be more persuasive 

than that of petitioners’ expert Dr. Ronald Kennedy on the subject of vaccine-strain 

measles virus persistence. Id. at *7, *128-32. 

The special master also identified at least two key flaws in the Unigenetics data 

and related articles (such as the 2002 Uhlmann article) that would have been evident 

even without Dr. Bustin’s analysis. First, the positive findings of measles virus 

persistence have not been successfully replicated by laboratories independent of Dr. 

Wakefield or Unigenetics, despite several efforts to do so. Second, the articles “do not 

include sufficient laboratory data to evaluate the conducted testing procedures and the 

validity of the test results.” Hazlehurst, 2009 WL 332306, at *124. Given the 

abundance of other evidence undermining the reliability of the Unigenetics test results, 

the special master’s consideration of Dr. Bustin’s evidence, even if erroneous, would not 

justify reversal of the special master’s decision. See Hines, 940 F.2d at 1526. 

B 

The Hazlehursts also argue that the special master disregarded critical evidence 

regarding the reliability of the Walker group’s test results, in violation of the Vaccine 

Act’s requirement to consider “all . . . relevant medical and scientific evidence.” 42 

U.S.C. § 300aa-13(b)(1). They assert that the special master ignored evidence—

including testimony from Dr. Hepner and exhibits from the Walker group’s 2006 IMFAR 
2009-5128 15 

poster presentation—showing that the Walker group used genetic sequencing to verify 

its test results. If the special master had given that evidence proper consideration, the 

Hazlehursts argue, she would have found that the Walker study reliably detected 

persistent vaccine-strain measles virus in the bowels of autistic children. The 

Hazlehursts therefore assert that the special master’s decision to accord little weight to 

the Walker group’s test results was arbitrary and capricious. We disagree. 

As an initial matter, even if the special master had made no explicit reference to 

the evidence that the Walker group used genetic sequencing, we would presume that 

she considered that evidence. See Medtronic, Inc. v. Daig Corp., 789 F.2d 903, 906 

(Fed. Cir. 1986) (“We presume that a fact finder reviews all the evidence presented 

unless he explicitly expresses otherwise.”). In this case, however, it is not necessary to 

rely on that presumption, as the special master’s opinion specifically refers to that 

evidence. Discussing Dr. Krigsman’s testimony, the special master explained: 

Dr. Krigsman stated that the preliminary findings of that [Walker group] 

study show that based on the obtained PCR results, measles virus is 

present in the biopsied gastrointestinal tissue taken from patients with 

autism and bowel disease and examined by Dr. Krigsman. Dr. Krigsman 

acknowledged, however, as did Dr. Hepner, that not all of the samples 

had been sequenced for vaccine strain measles. 

Hazlehurst, 2009 WL 332306, at *139 (citations to exhibits and testimony omitted). 

Thus, the special master clearly understood the testimony that some, though not all, of 

the Walker group’s samples were sequenced to confirm vaccine-strain specificity. 

Moreover, the exhibits that the special master cited in her opinion included the June 

2006 IMFAR abstract and IMFAR poster presentation—the very documents that the 

Hazlehursts contend were “ignored.” We thus cannot conclude that the special master 

failed to consider the evidence in question, in violation of 42 U.S.C. § 300aa-13(b)(1). 
2009-5128 16 

 

In any event, an examination of the cited exhibits and testimony reveals 

inconsistent and preliminary data that provides only minimal support for the petitioners’ 

claim that the Walker group confirmed the presence of vaccine-strain measles virus, as 

opposed to wild-type measles virus. While the abstract states that “PCR analysis on 

. . . tissue from an initial 82 patients showed that 70 (85%) were positive” for measles 

virus, the poster presentation states that “PCR analysis on . . . tissue from an initial 86 

patients showed that 57 (66%) were positive” for measles virus. With respect to 

sequencing, the abstract observes that “[f]ourteen [samples] have been verified by DNA 

sequence,” but it does not state whether the sequencing was vaccine-strain specific. 

The poster presentation, on the other hand, states: “Thirty five [samples] have currently 

been verified by DNA sequence. Six of the thirty five MV [measles virus] positive 

[samples] bear sequence that is specific to vaccine strain MV.” That information, which 

suggests that only a small number of samples were successfully sequenced for 

vaccine-strain measles virus, is confirmed by Dr. Krigsman’s testimony: “All we could 

say at the time of this poster is that, as far as vaccine-strain-specific sequencing 

positivity, a total of six specimens [] were positive . . . . So genetic material that was 

specific for vaccine-strain measles virus was positive in six.”2 Given that the Walker 

group’s data reflects only a small amount of vaccine-strain-specific sequencing, it was 

not inappropriate for the special master to include only a brief discussion of the Walker 

group’s sequencing efforts in her opinion. 

2

 The Hazlehursts cite portions of Dr. Hepner’s testimony and expert report for 

the proposition that the Walker group verified that the material it amplified by PCR was 

vaccine-strain measles virus. However, the cited material concerning sequencing 

discusses only “measles virus (MV)” generally and is therefore ambiguous regarding the 

number of samples successfully sequenced for the vaccine strain of the virus. 
2009-5128 17 

The special master’s decision to accord little weight to the Walker group’s data 

was largely based on the study’s other shortcomings and was thus well within her 

discretion in weighing the evidence. Most significantly, the special master found that 

the Walker group’s research was unpublished, preliminary, and incomplete. Hazlehurst, 

2009 WL 332306, at *124-25, *139, *150. Embodied only in a poster presentation, the 

Walker study was not subject to peer review and therefore has not been subjected to 

scrutiny from the greater scientific community. See id. at *16, quoting Daubert v. Merrell 

Dow Pharms., Inc., 509 U.S. 579, 594 (1993) (“The fact of publication (or lack thereof) 

in a peer reviewed journal thus will be a relevant, though not dispositive, consideration 

in assessing the scientific validity of a particular technique or methodology.”). In fact, 

Dr. Krigsman and Dr. Hepner repeatedly described the Walker group’s data as “partial” 

and “preliminary.” As the special master observed, Dr. Hepner testified that she 

“certainly wouldn’t draw any conclusions about the biological significance” of the Walker 

group’s test results at that early stage. In particular, Dr. Hepner noted the lack of a 

“proper control source” of tissue samples from children without autism spectrum 

disorders. She explained that the Walker group’s current data does “not give us any 

information yet about this cohort of patients relative to a different cohort of patients.” 

The special master also expressed misgivings about the Walker group’s use of 

controls in its study. The special master noted that “while positive controls (specifically 

‘an artificial laboratory construct’ of wild-type measles virus) have been run in each 

experimental run in the study, no negative controls have been run to date because the 

investigators are still looking for suitable negative controls.” Hazlehurst, 2009 WL 

332306, at *125. In their reply brief, the Hazlehursts dispute the special master’s 
2009-5128 18 

statement that “no negative controls have been run.” They argue that negative 

“technical” controls were run with every sample to check for contamination and to 

assure the reliability of the PCR testing, even though the Walker group lacked certain 

“experimental” controls, namely, control samples of tissue from children who tested 

negative for autism. 

The record is unclear as to precisely what negative controls were run. Although 

Dr. Hepner testified that “no-template negative controls” were run “as a control for 

contamination,” she also stated that the Walker group was still “in the process of 

procuring samples that would be appropriate negative controls.” She further noted that 

“the negative control at this point generally has been a no-template control because we 

don’t have access to the right material.” The confusion is compounded by Dr. Bustin’s 

testimony that he could not rule out the possibility of contamination—suggested by 

several indicators of unidentified genetic material in the Walker group’s poster 

presentation—because “there’s no negative control there.” 

What is clear from the record is that, at the time of the omnibus autism hearings, 

certain key controls used by the Walker group were incomplete and in flux. Most critical 

is the undisputed lack of a sufficient control group of non-autistic children with which to 

compare the positive findings in autistic children. If the Walker group were to find 

persistent measles virus at comparable rates in both autistic and non-autistic children, 

for example, such a finding would significantly undermine the petitioners’ theory that 

persistent measles virus contributes to the causation of autism spectrum disorders. 

Moreover, Dr. Hepner’s testimony suggests that the Walker group was also seeking a 

different type of positive control to rule out the possibility of cross-contamination. That 
2009-5128 19 

evidence further underscores the preliminary and unconfirmed nature of the Walker 

group’s results. 

Like the Court of Federal Claims, we do not believe that the Walker group’s small 

amount of vaccine-strain-specific genetic sequencing “carries enough weight to 

overcome the special master’s conclusion that the Walker group’s results were 

preliminary, unpublished, and not entitled to substantial weight.” Hazlehurst, 88 Fed. Cl. 

at 488. We therefore find no error in the special master’s determination that she could 

not “place much weight on the preliminary findings of Walker study . . . specifically the 

alleged findings of vaccine-strain measles virus in some of the bowel biopsies that were 

tested.” Hazlehurst, 2009 WL 332306, at *125. 

III 

Because we find no error in the special master’s consideration of the evidence, 

we also find no error in her decision to discount Dr. Corbier’s opinion that the MMR 

vaccine caused Yates’s autism. By Dr. Corbier’s own admission, his opinion depended 

heavily on the reliability of the scientific studies purporting to show measles virus 

persistence in autistic children. 

Compensation under the Vaccine Act is limited to those individuals whose 

injuries or deaths can be linked causally, either by a Table Injury presumption or by a 

preponderance of “causation-in-fact” evidence, to a listed vaccine. The special master 

concluded that the Hazlehursts’ evidence failed to demonstrate the necessary causal 

link, and the petitioners have not identified any reversible error in the special master’s 

decision reaching that conclusion. 

AFFIRMED.