Autism Not linked to Vaccines Containing Thimerosal

A News & Events entry posted on February 9, 2009

A new study from Italy adds to evidence that a mercury-based preservative once used in many vaccines doesn’t hurt children, offering more reassurance to parents. 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. The study compared the neuropsychological performance, 10 years after vaccination, of 2 groups of children exposed randomly to different amounts of thimerosal through immunization. Only one case of autism was found, and that was in the group that got the lower level of thimerosal.

The study concluded through the large number of statistical comparisons performed, the few associations found between thimerosal exposure and neuropsychological development might be attributable to chance. The associations found, although statistically significant, were based on small differences in mean test scores, and their clinical relevance remains to be determined.

Refer to the journal ’Pediatrics’ website for the full article.