Here's an
article by two doctors about autism and vaccines. The alleged culprit is thimerosal (sodium ethylmercurithiosalicylate - note the mecur[y]), a preservative used in some vaccines. The CDC claims that
no one is using thimerosal anymore, and
it doesn't cause autism, and the dates for the surge in autism and the introduction of thimerosal don't match, anyway.
The doctors claim that autism and similar developmental difficulties were unheard-of before thimerosal. The theory is mercury poisoning: the affected children are unable to excrete the mercury that comes to them from vaccines and maternal dental amalgams. The CDC is eliminating thimerosal (as a precaution, not an admission of its guilt), but the article claims that "vaccines containing 25 mcg of mercury per dose and carrying an expiration date of 2005 continue to be produced and administered."
The occasion of this article is pending legislation in California to ban thimerosal in vaccines (beyond trace levels) for both children and mothers by July 2006. Whether or not it passes, it seems that thimerosal and mercury dental amalgams are on their way out. If the autism rate then drops suddenly, I'll become a believer.