WASHINGTON (Reuters) - A special U.S. court ruled against three families on Thursday who claimed vaccines caused their children's autism.
The Vaccine Court Omnibus Autism Proceeding ruled against the parents of Michelle Cedillo, Colten Snyder and William Yates Hazlehurst, who had claimed that a measles, mumps and rubella vaccine had combined with other vaccine ingredients to damage the three children.
"Unfortunately, the Cedillos have been misled by physicians who are guilty, in my view, of gross medical misjudgment," Special Master George Hastings, a former tax claims expert at the Department of Justice, wrote in the 183-page Cedillo ruling.
The families sought payment under the National Vaccine Injury Compensation Program, a no-fault system that has a $2.5 billion fund built up from a 75-cent-per-dose tax on vaccines.
Instead of judges, three "special masters" heard the three test cases representing thousands of other petitioners.
They asked whether a combination vaccine for measles, mumps and rubella, or MMR, plus a mercury-containing preservative called thimerosal, caused the children's symptoms.
"The evidence does not support the general proposition that thimerosal-containing vaccines can damage infants' immune systems," Hastings wrote, after reviewing tens of thousands of documents and hours of oral arguments.
"I further conclude that while Michelle Cedillo has tragically suffered from autism and other severe conditions, the petitioners have also failed to demonstrate that her vaccinations played any role at all in causing those problems."
Michelle's parents argued that she was a normal baby until she received the vaccine.
Experts say parents often link vaccines with their children's symptoms because they are vaccinated at an age when autism and related disorders are often first diagnosed.
"We need ongoing research into the causes of autism, but cannot let unfounded myths keep us from giving our children the proven protection they need against infectious diseases," the American Medical Association said in response to the ruling.
The Institute of Medicine reviewed the evidence in 2001 and 2004, and determined there was no link between vaccines and autism. Many other studies have shown no link, but a small and vocal group of parents continues to press the case.
The advocacy group Autism Speaks said the ruling did not necessarily clear vaccines, or any other potential cause.
"We will continue to support authoritative research that addresses unanswered questions about whether certain subgroups of individuals with particular underlying medical or genetic conditions may be more vulnerable to adverse effects of vaccines," the group said in a statement.
Hastings rejected this argument in his ruling.
More than 5,300 cases were filed by parents who believed vaccines may have caused autism in their children and were seeking payment under the National Vaccine Injury Compensation Program. The no-fault payout system is meant to protect vaccine makers from costly lawsuits that drove many out of the vaccine-making business.
Autism is a mysterious condition that affects as many as one in 150 U.S. children. The so-called spectrum ranges from mild Asperger's Syndrome to severe mental retardation and social disability, and there is no cure or good treatment.
Editing by Will Dunham