Beating (what should be) a Dead Horse

an Italian study shows that thimerosal has essentially no effect on brain function in children who got a whooping cough vaccine.

1400 children who got a thimerosal-based vaccine for pertussis in the early 90s were tested for brain function impariments. The vaccines had different amounts of the mercury-based preservative in them (one had twice the amount of the other), so if thimerosal had any effect on the brain — like causing autism — then the children in the study should have clearly different results depending on what vaccine they got.

They didn’t, above what would be expected from chance variations. Even better, the study was randomized in such a way that outside factors like environment wouldn’t play a role, so antivaxxers cannot say it was something else that may be affecting these results.

Now let’s be clear: thimerosal has been known scientifically not to have any link to brain disorders for years (link goes to a Word doc), and the Measles/Mumps/Rubella (MMR) vaccine never contained thimerosal anyway. Antivaxxers wrongly targeted thimerosal as a health risk, and thimerosal was removed from vaccines in 2001, but no reduction in autism spectrum disorder diagnoses occurred. In other words, thimerosal is not linked with autism

This is all via The Bad Astronomy Blog. If you're woondering why, it's because Dr. Phil Plait, the Bad Astronomer himself, is the current President of the James Randi Educational Foundation. Check them both out. (Note: The link to the BABlog is directly to the cited post).

Edit: For a more detailed analysis, by an actual Neurologist, check out Dr Steven Novella's Neurologica.