Thursday, the United State's Vaccine Court Omnibus Autism Proceeding delivered its ruling to three families who claimed that vaccines were the cause of their children's autism. But the three are among more than 5,500 cases that have been filed making that allegation with the National Vaccine Injury Compensation Program.

A slew of major health organizations and scientific studies long ago concluded that there was no link between vaccines and autism, a condition whose victims lack social skills, can’t communicate well and engage in repetitive behaviors. But thousands of parents are seeking federal compensation for alleged vaccine injuries and pinning their hopes on a special court in Washington to find merit in their claims.

However the cases have been intensely watched. Both sides hoped that a win in "vaccine court" would end the controversy, which was sparked by a 1998 paper in the British journal Lancet that linked developmental delays and MMR vaccinations. That paper is controversial; 10 of the 13 authors retracted it in 2004, but the lead author, Andrew Wakefield, has not.

Doctors and other medical experts overwhelmingly applauded the ruling, maintaining that it reinforces the message that vaccination does not lead to autism. "This is a real victory for children and a great day for science," said pediatrician Dr. Paul Offit, chief of Infectious Diseases and the director of the Vaccine Education Center at the Children's Hospital of Philadelphia, during a Thursday press conference sponsored by the vaccination advocacy group Every Child by Two. "I hope that this decision will finally put parents' fears to rest."

The court must still rule on test cases contending that thimerosal-containing vaccines alone could have caused autism, a theory that medical authorities have long dismissed as contrary to the evidence. Thimerosal was used to keep bacteria from growing in multi-dose containers. The MMR vaccine has never contained thimerosal, but some other routinely recommended vaccines such as the hepatitis B vaccine did. Thimerosal was phased out of most shots by 2000.