Science Panel Finds No Link Between Autism and MMR Vaccine
WebMD News Archive
April 23, 2001 (Washington) -- A panel of independent experts has concluded that the measles, mumps, and rubella vaccine, or MMR, does not cause autism, a devastating brain disorder for which there is no cure. But the announcement by the 15-member committee convened by the National Academy of Sciences' Institute of Medicine (IOM) left the door open just a crack, which could allow the controversy surrounding the MMR vaccine to continue.
In its report released Monday, the IOM said that after considering evidence available today, it is reasonable to conclude that the vaccine does not cause autism. The scientists also said the evidence that does exist "shows no association" between the vaccine and the condition. Nonetheless, the panel could not rule out that MMR vaccine could contribute to autism in a small number of children.
One highly publicized and disputed 1998 British study brought suspicions about the vaccine to the forefront. It involved 12 children who had received MMR shots. They seemed to develop normally at first, but then developed bowel problems and regressed emotionally, exhibiting autism-like symptoms, such as bizarre ritualistic or repetitive behaviors.
Both the CDC and the National Institutes of Health asked the Immunization Review Safety Committee to evaluate the autism-MMR connection. The IOM committee then reached its conclusion about MMR and autism, which is similar to the conclusions made by the American Academy of Pediatrics and the World Health Organization.
After reviewing the existing literature, the panel could find no biological mechanism for the vaccine-disease relationship, nor could members justify the theory that a viral infection like measles, triggered by the vaccine, could produce bowel inflammation that may leak into a person's system and produce a kind of brain poisoning.
MMR vaccine supporters, however, are convinced of the benefits of the shot. They note that the three-in-one injection has virtually eliminated measles, mumps, and rubella in the U.S. For instance, measles cases dropped from about 400,000 cases a year to just 100 in 1999. However, in the developing world, where kids don't get the vaccine, measles may kill 1 million youngsters annually.