Blogging has been light as I've spent time assembling the next Carnival. However, this article by Arthur Allen on thimersol is well worth a read.
Thimersol in vaccines has been linked to autism, and many people (including Indiana Representative Dan Burton, who has an autistic relative) believe this to be fact. Arthur Allen, in fact, wrote on the subject two and a half years ago. But unlike many people for whom achieving a goal is more important than truth, he has highlighted the numerous followup studies that show no significant link. In particular, one study from Denmark shows diagnoses of autism increased, despite the ceasing of the use of thimersol preservatives in vaccines.
I freely admit to not being a research scientist or doctor, but I pay enough attention to the world to see that diagnosis of autism and related conditions, like Asperger's syndrome, have increased due to a greater understanding of the condition, leading to better diagnoses. With that background, just about anything could have been linked to autism, if you just looked at correlation. Remember, though, that correlation does not necessarily imply causation.
Autism remains a subject that we don't understand. But increased research, not demonizing an effective vaccine preservative, is the path to better understanding.