Test cases, rulings, and scientific evidence in the U.S. Vaccine Court.
The Omnibus Autism Proceedings (OAP) were a coordinated series of test cases heard in the U.S. Vaccine Court (the U.S. Court of Federal Claims) between 2007 and 2010. The proceedings addressed over 5,500 petitions filed by families who alleged that childhood vaccines — particularly the MMR vaccine and vaccines containing thimerosal — caused autism spectrum disorder (ASD) in their children.
The OAP represented the largest coordinated vaccine litigation effort in U.S. history. All test cases were dismissed. Special Masters found that the scientific evidence did not support a causal link between the vaccines at issue and autism.
Autism diagnosis rates increased significantly during the 1990s, coinciding with an expansion of the childhood vaccine schedule. Some parents and advocacy groups attributed this to MMR vaccination (based on the since-retracted Wakefield study) or to thimerosal, a mercury-based preservative used in some vaccines.
Over 5,500 families filed VICP petitions alleging vaccine-caused autism. Rather than adjudicate each case individually, the Vaccine Court established the OAP to hear coordinated test cases that would establish precedent for all pending claims.
The OAP organised claims around three causation theories: (1) MMR vaccine alone causes autism; (2) MMR vaccine combined with thimerosal-containing vaccines causes autism; (3) thimerosal-containing vaccines alone cause autism.
Six test cases were selected — two for each causation theory. All six were dismissed.
Test cases: Cedillo v. HHS and Hazlehurst v. HHS (2009).
Special Masters found no reliable scientific evidence that MMR vaccination causes autism. The Wakefield study, the primary evidence relied upon by petitioners, was found to be scientifically unreliable.
Test case: Snyder v. HHS (2009).
Special Masters found no reliable evidence that the combination of MMR and thimerosal-containing vaccines causes autism. Expert testimony supporting the theory was found to be speculative and not grounded in established science.
Test cases: King v. HHS, Mead v. HHS, and Dwyer v. HHS (2010).
Special Masters found no reliable scientific evidence that thimerosal exposure causes autism. Epidemiological studies from multiple countries consistently showed no association between thimerosal exposure and autism rates.
The Special Masters reviewed extensive scientific evidence including:
Following the test case rulings, the remaining 5,500+ individual petitions were dismissed. Families were permitted to pursue civil litigation but faced significant legal barriers under the Bruesewitz v. Wyeth precedent.
Although the OAP found no causal link, thimerosal was phased out of routine childhood vaccines in the U.S. between 1999 and 2001 as a precautionary measure. Autism diagnosis rates continued to rise after removal, providing further evidence against the thimerosal hypothesis.
The OAP proceedings, combined with extensive independent research, contributed to the current scientific consensus that vaccines do not cause autism. This consensus is maintained by the CDC, WHO, AAP, and every major medical and scientific organisation globally.
Despite the legal and scientific outcomes, belief in a vaccine-autism link persists among some groups. The controversy continues to affect vaccine confidence and is a significant driver of vaccine hesitancy in the United States and globally.
Explore vaccine law, mandates, exemptions, and the legal framework in the United States.
Learn about the National Vaccine Injury Compensation Program and the Office of Special Masters.
The history of the MMR vaccine and autism claim, including the fraudulent Wakefield study.