"But until we invest more money in doing large-scale studies we're not going to be able to find the answers," Dawson said.
The findings do not lay to rest the controversy surrounding whether or not thimerosal, which was once a component of children's vaccines, contributed to autism risk because the preservative was still being phased out at that time.
Visit the U.S. National Institute of Neurological Disorders and Stroke for more on autism spectrum disorders.
Copyright © 2011 HealthDay. All rights reserved.