A landmark study of the measles, mumps and rubella (MMR) vaccine has concluded there's no link between it and autism.

The study is published in the New England Journal of Medicine.

Autism is a developmental condition causing physical, social and learning problems.




Researchers surveyed all children born in Denmark from January 1991 to December 1998. Denmark was chosen because of the detailed health records officials keep.

They looked at 440,655 children who had received the MMR vaccine and compared them to the 96,648 who did not.

In the group that was vaccinated, 316 children were diagnosed with autism by the Danish Psychiatric Central Register.

Since 1987, Danish authorities have recommended all children be given MMR vaccine at 15 months of age and again at 12 years. The average age of children who got it for the first time was 17 months.

They concluded there was "no association between the development of autistic disorder and the age at vaccination, the interval since vaccination or the calendar period at the time of vaccination."

According to their findings:

  • The risk of autism was the same in vaccinated and un-vaccinated children
  • there are no clustering of cases of autism
  • None of the autistic disorders were associated with MMR vaccination

In Denmark, as in other countries, the prevalence of autism rose. In the 1980s, its was less than two cases for every 10,000 children between the ages of five and nine. By 2000, it was 10 cases for every 10,000 children.

The study was supported by the Danish National Research Foundation, the U.S. National Immunization Program, the Centers for Disease Control and the National Alliance for Autism Research.

It says the rise in autism cases can be attributed to "better reporting and wider use of...diagnosis to describe children with unexplained cognitive and behavioral disorders."

The editorial says parents have jumped to their own conclusions because the MMR vaccine is given after the child turns one and parents often notice the early signs of autism — poor speaking and social skills — around the second and third years of life.

This study supports an earlier one by the World Health Organization, which stated there was no link between MMR vaccine and autism.

That study surveyed 50 years of research on 2,000 children.