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New research demolishes link between MMR vaccine and autism

Hilary Bower , London

A leading virologist is calling on the scientific community to spend no more time investigating alleged links between the MMR (measles, mumps, and rubella) vaccine, inflammatory bowel disease, and autism after the publication last week of two further studies, which seemed to demolish the theory that vaccination increased the risk of the conditions.

The studiesone published in the Lancet by a team from the Royal Free Hospital Medical School, London, the second in Current Problems in Pharmacovigilance from a specially convened working party of the Committee on Safety of Medicinesboth found no evidence that the vaccine causes either autism or inflammatory bowel disease, which has been suggested as the link mechanism.

In the Royal Free's study, Brent Taylor, professor of community child health, and colleagues investigated 498 children with autism born since 1979 in the North Thames region. They found that the age at which autism was diagnosed was the same regardless of whether they had received the MMR vaccine before or after 18 months old or had never been vaccinated.

There was no clustering of developmental regression after vaccination, and no more children in the group with autism had been immunised than in the general population of the region. The team said that, although the number of cases of autism had increased steadily since 1979, there was no sign of any steep rise coinciding with the introduction of the MMR vaccine in 1988.

The Committee on the Safety of Medicines' study examined medical records of 92 children with autism and 15 with Crohn's disease; the records had been passed to the committee by a firm of solicitors. Evidence of autism before vaccination was found in 36 cases, and another 28 showed family history of the condition. Eight autistic children and four with Crohn's disease seemed to have developed symptoms after MMR vaccination, but, the authors said, the small numbers and the fact that onset of autism frequently occurs around age 18 months meant that this is not enough to prove causation.

Add these findings to those of last year's Medical Research Council's team of 37 experts who examined the issue and also concluded that no link existed, and, said Norman Begg, head of the Communicable Disease Surveillance Centre's immunisation division, it is clear this issue must now be laid to rest. "These are important papers. They are further evidence that this vaccine causes neither autism nor inflammatory bowel disease," he stated.