In a major setback for the fight to link autism to vaccines, a special federal court ruled yesterday that the measles-mumps-rubella vaccine and vaccines that contained a mercury-based preservative were not connected to autism that developed in three children.
The cases of the Cedillo, Hazlehurst and Snyder families could sink the claims of several hundred other families who believe the MMR vaccine alone or in combination with vaccines containing the preservative thimerosal caused their children's autism, said Curtis Webb, a lawyer for the Hazlehurst family.
The outlook appeared particularly grim, he said, because these three cases were considered among the strongest.
"We're extremely disappointed," Webb said. "It wasn't even a close case."
The families' attorneys are considering appeals, the lawyer said.
Vaccine supporters and public health experts applauded the decision by the U.S. Court of Federal Claims, hoping that it would reassure parents that the shots recommended by federal scientists are safe.
"It's a great day for science, and I'd like to think it's also a great day for children with autism," said Dr. Paul Offit, chief of infectious diseases at Children's Hospital of Philadelphia and co-inventor of the rotavirus vaccine, a standard childhood immunization that does not contain thimerosal.
Offit said he understands that many parents have been scared by the controversy but believes those who refused to vaccinate their children contributed to a 12-year high in measles cases last year and a recent outbreak of bacterial meningitis.
Both of these outbreaks could have been prevented by standard childhood vaccinations, he said.
"It's time to put the vaccine hypothesis aside and focus on the real causes of autism and not be diverted by a dead end," said Offit, who was not involved in the case.
Congress set up the special vaccine court in 1986 when pharmaceutical companies faced a liability crisis. Vaccines were being blamed for catastrophic injuries to children, and some vaccine manufacturers threatened to quit the business.
The court shields vaccine makers from paying damages, drawing money from a surcharge levied on every vaccine.
Parents who believe their children have been injured by vaccines can file petitions at this court and receive compensation from the surcharge pool.
About 5,000 families have filed claims involving autism, a spectrum of developmental disorders whose hallmarks are impaired social interaction and communication.
The appointed judicial officers in this case, known as special masters, decided to hear test cases on different causation theories to develop general principles that they could apply to the flood of claims.
Three special masters heard the cases of the Cedillo, Hazlehurst and Snyder families in 2007. Lawyers for the families argued that vaccines containing thimerosal weakened the children's immune systems, allowing the viruses in the MMR vaccine to take hold and lead to autism.
In the Hazlehurst case, lawyers for the family came to argue that the MMR vaccine was the primary culprit.
Thimerosal was used to keep bacteria from growing in multidose containers. The MMR vaccine never contained thimerosal, but some other routinely recommended vaccines such as the hepatitis B vaccine did.
Thimerosal was phased out of most shots around 2000. Trace or small amounts of thimerosal remain in a few vaccines recommended for children, including the flu shot.
The special masters rejected practically all of the families' arguments.
"I concluded the evidence was overwhelmingly contrary to the petitioners' contentions," George L. Hastings Jr. wrote in the Cedillo opinion, which was similar to the others.
"The expert witnesses presented by the respondent were far better qualified, far more experienced and far more persuasive than the petitioners' experts."
Several parent-advocates were frustrated by the decisions.
"I'm sure the decision was based on some of the current science that is out there and the scientific community hasn't invested in the types of independent research necessary to get to the bottom of the issue," said Rick Rollens, the parent of an autistic son and co-founder of the University of California, Davis M.I.N.D. Institute.
Rollens and others said these verdicts won't make parents stop questioning the safety of vaccines, especially when parents witness changes in their children right after vaccination.
"There's no denying what happens to your child when you see it first-hand," said Rollens, a Sacramento, Calif., resident. "Maybe we haven't asked all the right questions yet."
The special masters are still working on another group of test cases alleging that the thimerosal itself causes autism.
Final briefs on those cases are still being filed, with decisions expected after the summer.
Yesterday's decisions "won't resolve the thimerosal cases," said Webb. "There are more people that focus on thimerosal than focus on MMR. ... Those cases are still viable."