Doctors who investigated the health risks of the three-in-one measles, mumps and rubella (MMR) vaccine have found no evidence to suggest it can cause autism in children.
A group of medical specialists brought together by the Medical Research Council rejected claims made in 1995 and 1998 that the vaccine is linked with autism and bowel disease.
The subsequent panic caused a serious fall in childhood vaccinations, raising fears of a measles outbreak that could do more harm than the supposed risk the vaccine.
Professor Alan McGregor, of King's College London, who chaired the committee, said the specialists looked at all the evidence that is published or about to be published, as well as interviewing senior scientists, but still failed to find a link between vaccinations and autism.
The committee also interviewed Andrew Wakefield, the consultant at the Royal Free Hospital in London whose research triggered the scare over the MMR vaccine after it was published in The Lancet.
Professor McGregor said the committee found the research data published in The Lancet was insubstantial and should not have been used to support claims that the vaccine causes autism. "The reality is that the Lancet research generated a huge amount of coverage and caused a lot of damage. I hope the editor sees fit to comment on our report," Professor McGregor said. "Without doubt the potential damage done by these claims is enormous."
Research published last year on 498 autistic children by a separate group at the Royal Free Hospital, led by Professor Brent Taylor, found no association with the MMR vaccine.
The researchers said the rise in autism, which began in 1986 before the introduction of the MMR vaccine, is probably due to the condition being better recognised and diagnosed than in the past.
The research council announced yesterday that it will fund the biggest study yet into autism, led by Professor Andrew Hall of the London School of Hygiene and Tropical Medicine. It will investigate the possible causes of this mysterious condition, where children find it difficult to develop normal social relationships. The research will involve a study of the health records of 2 million people to see if birth problems or viral infections in the womb may play a role. The study will also look at vaccinations.
Isobella Thomas, one of the many parents of autistic children who believe the MMR vaccine was responsible, says she is not convinced by Professor McGregor's findings.
"We know 100 per cent that our children are vaccine damaged. Within hours of their jabs, two of my children reacted and now have a new form of autism," Mrs Thomas said.