CHICAGO — A new study from Italy adds more evidence that a mercury-based preservative once used in many vaccines doesn't hurt children.
In the early 1990s, thousands of healthy Italian babies in a study of whooping cough vaccines got two different amounts of the preservative thimerosal from all their routine shots.
Ten years later, 1,403 of those children took a battery of brain function tests.
Researchers found small differences in only two of 24 measurements and those "might be attributable to chance," they wrote in the February issue of the journal Pediatrics, released today.
Only one case of autism was found, and that was in the group that got the lower level of thimerosal.
Autism is a complex disorder featuring repetitive behaviors and poor social interaction and communication skills.
Scientists generally think genetics plays a role in the disorder. A theory that thimerosal is to blame has been repeatedly discounted in scientific studies.
