More Research Discredits Link Between Autism and Measles Vaccine
March 6, 2001 (Washington) -- Researchers continue to search furiously for any clues linking the measles-mumps-rubella (MMR) vaccine and autism, but in the latest study to weigh in on the issue, they report that the vaccine poses little, if any, risk. While looking at trends in vaccine use, they found that although the rate of autism increased almost fourfold during a 14-year period, use of the MMR vaccine increased only slightly during this time period.
Because the study looked at cases of autism after they were reported rather than when they were diagnosed, the researchers could not completely rule out the vaccine as one possible cause. "But supposing the connection is real and the vaccine is one of the causes, these data show it could not be a major contributor," lead author Loring Dales, MD, MPH, an epidemiologist and the principal researcher, tells WebMD.
Autism is a disorder of brain development that is characterized by problems with social interaction, communication skills, a strict routine, and the need for repetitive behavior, such as swaying or watching the same video over and over again. There is no cure, but intensive education can help autistic children develop new skills. Unfortunately, these programs are expensive and can cost anywhere from $8,000 to $100,000 a year for a residential school setting.
But for parents with newly diagnosed children, these day-to-day challenges and expenses are not the only hurdles they must overcome. Often, parents of autistic children also must deal with the simple frustration of not knowing why their child is autistic.
To investigate the possible connection, Dales and two of his colleagues at the California Department of Health compared 15 groups of children born between 1980 and 1994. During that period, California experienced a marked increase in the number of reported cases of autism, from 44 cases for every 100,000 live births in 1980 to about 208 cases for every 100,000 live births in 1994.
This is a relative increase of about 373% in the number of autism cases, but Dales says the researchers found that the concurrent increase in the state's MMR immunization rate was significantly smaller, only 14%.
For supporters of the MMR vaccine, the current study available in the March 7 issue of the Journal of the American Medical Association could not have come at a better time.
The Institutes of Medicine is scheduled this week to once again review the possible connection between autism and the MMR vaccine. Once the IOM completes this review, which it began in January, it will then advise U.S. health authorities on what course of action they should take in terms of recommending the childhood vaccination.
The fear among some parents and researchers that the vaccine might trigger autism is largely due to the apparent increase in autism cases since the introduction of the MMR vaccine. But to date, there is no evidence to clearly establish a causal link between the MMR vaccine and autism.