Refocus autism research

Medical science does not know what causes autism, but a comprehensive examination of medical research worldwide has found no convincing evidence of a link between it and the measles-mumps-rubella vaccine. Likewise, the investigation found no connection between autism and vaccines that contain the mercury preservative called thimerosal.

These findings should be helpful in two respects: Parents should not fret about getting their children immunized for fear their children will develop autism. The findings should also help steer the research to genetic and environmental causes for the brain development disorder.

The investigation's findings are further bolstered by the fact that mercury was removed from most childhood vaccinations by 2002. If there was a connection to the preservative, there would have been a corresponding drop in autism cases. The number of children with autism has risen over the past decade, although experts disagree how large the increase is.

The review committee, composed of expert physicians and scientists who have no connection to the pharmaceutical industry, met nine times to gather evidence on the various claims. The group, affiliated with the National Academy of Sciences, determined that five studies worldwide found no evidence of a link between autism and vaccines with mercury. Three studies found evidence, but the committee deemed the researchers' study methods were flawed.

Despite examinations that went further than ever in discrediting claims that vaccines cause autism, critics say other research is under way that shouldn't be dismissed. Rep. Dave Weldon, R-Fla., said the report will not "put to rest the concerns of parents who believe their children were harmed" by vaccines.

There is some risk associated with childhood vaccination, but it is small compared to the risks of contracting childhood diseases, some of them life-threatening. Immunizations not only help protect an individual's health, they help ensure immunity in the general population.

As with so many diseases and disorders that baffle medical science as to their causes and possible cures, it is understandable that the loved ones of children who have autism have demanded further investigation between vaccines and the brain development disorder.

But there comes a time when science and subsequent reviews discounting these theories have to be considered convincing. As Dr. Marie McCormick, professor of maternal and child health at Harvard University, who led the study, observes, autism research needs to focus on "more productive" areas such as the role of genetics and their interaction with environmental factors and nongenetic influences. Perhaps then the cause behind this complex disorder can be determined.