Immunization Issues

Measles-Mumps-Rubella Vaccine and Autism

Updated: April 7, 2004

At a public briefing on Monday, April 23, 2001, the Institute of Medicine’s (IOM) Committee on Immunization Safety Review released a report in which they conclude that the evidence favors rejection of a causal relationship between the measles-mumps-rubella (MMR) vaccine and autism spectrum disorder, commonly known as autism. The Committee concluded that:

  • the epidemiological evidence shows no association between MMR and autism;
  • case studies based on small numbers of children with autism and bowel disease do not provide enough evidence to draw a conclusion about a causal relationship between these symptoms and administration of the vaccine;
  • biological models linking MMR and autism are ‘fragmentary;’ and
  • there is no relevant animal model linking MMR and autism.

Therefore, the Committee recommended maintaining the current policies relating to licensure and administration of the MMR vaccine in the United States. The Committee Chair, Marie C. McCormick, M.D., Sc.D., professor of maternal and child health at the Harvard School of Public Health, stated at the briefing that while no vaccine is 100% safe, the MMR vaccine is ‘as safe as a vaccine can get.’

The Committee reviewed published and unpublished material, and also heard testimony from a variety of witnesses, including Dr. Andrew Wakefield, the author of a well-publicized study published in The Lancet in 1998. This study seemed to indicate that the onset of autism and gastrointestinal problems were associated with the receipt of the MMR vaccine. Dr. McCormick noted that the Wakfield study was published as an observation for further investigation and never claimed to prove the relationship. She further noted that the Committee reviewed numerous studies that examined Wakefield’s hypothesis and were unable to find evidence to support it.

Current research on autism has established that there is a strong genetic component to the disease, however, the Committee report notes that ‘other factors, including infectious, neurologic, metabolic, immunologic, and environmental insults, may play significant roles.’ Therefore, although the Committee felt that a relationship between MMR vaccine and autism would be extremely rare, if it occurred at all, they recommend that research to examine this possible relationship continue.

The full text of the report is available at www.iom.edu/imsafety