IOM Researchers Find No Evidence Linking Autism, MMR Vaccine; Congressional Hearing in Issue Tomorrow

There is no evidence linking the measles-mumps-rubella (MMR) vaccine to the "dramatic rise" in autism among children, according to a new report released April 23 by the Institute of Medicine. The Philadelphia Inquirer reports that the findings were drafted by a panel of 15 scientists who based their conclusions on a "comprehensive review" of previously published studies as well as ongoing research (Collins, Philadelphia Inquirer, 4/24). A 1998 British study suggested a connection between the vaccine and an increased incidence in autism (AP/Richmond Times-Dispatch, 4/24). In 1999 and 2000, the House Government Reform Committee held hearings on the on the issue, prompting the CDC and the NIH to request the IOM report (Carroll, Wall Street Journal, 4/24). The new IOM study "debunked" the findings of the British research, stating that since the study only included 12 children, it was "too small to prove anything." In addition, the IOM report pointed to other problems with the British study, including possible selection bias by researchers (Philadelphia Inquirer, 4/24). However, the IOM panel said it "could not exclude the possibility" that the vaccine could contribute to autism in "a small number of children," and urged further testing. The report concluded that no changes should be made in how the vaccine is administered (Wall Street Journal, 4/24). The MMR vaccine is given to children at 12 months and then again at age four and is required before a child can enter school in the United States. IOM officials said that the panel members "had no connection to vaccine manufacturers or to federal regulatory agencies" (Philadelphia Inquirer, 4/24). To read a copy of the report, go to http://www.nap.edu/books/0309074479/html/.

Missing Link?
Dr. Bruce Gellin, director of the National Network for Immunization Information and a physician at Vanderbilt University, said the findings will "help to dispel unfounded public fears about vaccines in general and the MMR [vaccine] in particular." Dr. Tom Vernon, vice president for policy, public health and medical affairs at Merck & Co., which first developed the MMR vaccine in 1971, added, "The vast weight of the evidence refutes the claims (that MMR causes autism)" (Philadelphia Inquirer, 4/24). Gellin said that the panel's report represents the third study "dismissing" the link between autism and the MMR vaccine. "For parents, they should know that this information has been looked at up, down and sideways ... and it all says the same thing" (Wall Street Journal, 4/24). Still, some researchers have not dismissed the potential link between vaccination and autism. Rick Rollens, co-founder of Families for Autism Treatment at the University of California-Davis, said that the study "is not likely to put to rest concerns" about the vaccine. He said that the new study "sounds ... like an inconclusive report, and I don't think we can expect much more than that when you consider how little research has been done into this question" (Manning, USA Today, 4/24). The House Government Reform Committee is slated to take up the issue tomorrow at a congressional hearing. Andrew Wakefield, the British physician who conducted the 1998 study, is scheduled to testify (Philadelphia Inquirer, 4/24).

Autism Increasing
While the report dismisses the link between the MMR vaccine and autism, scientists are trying to understand why the rate of autism "seems to be rising," the New York Times reports. Ten years ago, autism was thought to affect one in every 10,000 children, but recent figures suggest that one in 500 children may have "some form of" the disorder. Robert Byrd, an epidemiologist at the University of California-Davis, is conducting a statewide study examining whether the increase is due to misdiagnosis or "a greater awareness of autism among physicians." But other factors may be at work, scientists say. Some scientists believe that autism could be linked to a handful of genes, and some are looking at whether environmental pollutants, like mercury from municipal waste incinerators, could affect developing brains (Blakeslee, New York Times, 4/24).