No link found between vaccine mercury and autism

Mon Sep 13, 2010 3:38am EDT
 

By Frederik Joelving

NEW YORK (Reuters Health) - A new government study adds to the evidence that thimerosal, a mercury-based preservative until recently found in many vaccines, does not increase children's risk of autism.

It shows kids who had been exposed as babies to high levels of the preservative -- through vaccines they received or their mothers received while pregnant -- were no more likely to develop autism, including two distinct subtypes of the condition.

"This study should reassure parents about following the recommended immunization schedule," said Dr. Frank Destefano, director of the Immunization Safety Office at the Centers for Disease Control and Prevention (CDC) in Atlanta, and the study's senior author.

Concerns about a link between vaccines and autism were first raised more than a decade ago by British physician Andrew Wakefield.

His report, based on 12 children, has since been discredited and was retracted earlier this year by the journal that published it. In the meantime, it sparked a fierce worldwide debate among scientists and a health scare that caused many parents to shy away from recommended vaccines like the one against measles, mumps and rubella.

Outbreaks of all three diseases followed.

One widespread worry has been that thimerosal might play a role in the development of autism, a condition that affects as many as one in 110 U.S. children, according to the CDC.

Most scientists consider autism a developmental disorder, likely influenced by genes.   Continued...