## Facts

- Yates Hazlehurst received the MMR vaccine in February 2001 shortly before his first birthday.
- His parents reported normal early development, followed by developmental and gastrointestinal problems beginning in mid-2001.
- Yates was diagnosed with autism in July 2002.
- His parents filed a petition under the National Childhood Vaccine Injury Act alleging the MMR vaccine caused his autism.
- Petitioners advanced a multi-step causation theory: (1) measles component caused immune dysfunction and inability to clear measles virus, (2) persistent virus caused chronic gastrointestinal and brain inflammation, and (3) brain inflammation caused autism.
- Petitioners relied heavily on PCR testing and publications from the Unigenetics laboratory, which purported to detect measles virus genetic material in tissue samples from autistic children.
- The government presented Dr. Stephen Bustin, a molecular biologist and PCR expert, who reviewed Unigenetics’ documentation and practices and opined that methodological and protocol failures rendered the lab’s results unreliable.

## Issues

1. Whether the special master abused discretion by admitting and relying on Dr. Bustin’s expert testimony and reports criticizing the reliability of Unigenetics’ PCR work.
2. Whether the special master’s determination that petitioners failed to prove, by a preponderance of the evidence, that the MMR vaccine caused Yates’s autism was arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.

## Decision

- The Federal Circuit affirmed the judgment upholding the special master’s denial of compensation.
- The court held the special master did not abuse discretion in admitting and crediting Dr. Bustin’s testimony because it was relevant to the reliability of evidence central to petitioners’ causation theory.
- The court held the special master’s causation findings had a rational basis in the record and were not arbitrary or capricious.
- The court rejected claims that petitioners were denied fairness or due process, noting they had substantial time and opportunity to respond and develop counterevidence.

## Legal Principles

- Vaccine Act appellate review of a special master’s fact-finding and evidentiary rulings is highly deferential; the question is whether the decision is arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.
- Special masters have broad discretion to admit and weigh evidence in Vaccine Act proceedings, which are less formal than ordinary civil litigation.
- A petitioner must prove actual causation by preponderant evidence, including a medically plausible “logical sequence of cause and effect.”
- An appellate court does not reweigh competing expert testimony; credibility and weight determinations are sustained if rationally supported by the record.
- Where a causation theory materially depends on scientific testing, demonstrated methodological flaws that undermine the reliability of that testing can reasonably support rejection of causation.

## Conclusion

The Federal Circuit sustained the denial of Vaccine Act compensation because the special master reasonably admitted and credited expert testimony undermining the reliability of the laboratory evidence supporting petitioners’ MMR-autism theory and, on the full record, permissibly found petitioners failed to prove causation by a preponderance of the evidence.


Hazlehurst v. Sec'y of Health & Hum. Servs., 604 F.3d 1343 (Fed. Cir. 2010)