Do vaccines given to infants and very young children somehow promote autism? This is the idea that researchers have been investigating and parents have been debating since a 1988 study of 12 children suggested such a link, provoking a wave of concern.

A new study, along with two previous studies, discredits the 1988 research and has found no evidence of a link between the MMR (measles, mumps, rubella) vaccine and autism, a wide-ranging spectrum of disorders, which usually leave children socially disengaged and sometimes unable to use language.

These new findings are based on a sample of almost 250 children aged between 10 and 12, from a population of 57,000, born between 1990 and 1991 in one area of Southern England. Ninety-eight of the children had an autism spectrum disorder, and two comparison groups: 52 children with special educational needs, but no evidence of autism spectrum disorders, and 90 children who were developing normally. The prevalence of autism and related disorders ranges from 6 to 12 cases per 1000 children.

All the children had been vaccinated at least once against MMR, which is given in two doses. But not all of them had been given both doses.

Children who were autistic and those with special needs were less likely to have received the second dose of MMR, possibly reflecting parental concern about vaccination following the diagnosis of a developmental problem. The authors point out that theirs is now the third, and largest, study that has failed to show a link between the MMR and autism.

This study is published in the January issue of the Archives of Disease in Childhood.