Something to keep in mind regarding vaccines:"One dose from a multiuse vial contains about 25 micrograms of mercury. By comparison, a tuna fish sandwich contains about 28 micrograms of mercury."
A friend of mine, who is a child psychiatrist, helped me understand that although the symptoms of autism usually show up within the first year, they are often not diagnosed until years 2 and onward, and this is what led some people to speculate that perhaps something in vaccines was causing autism. Unfortunately, for these parents, there is no evidence that vaccines, specifically thermisol, is related to the development of autism. I say unfortunately, because I know that parents of children with autism spectrum disorders want an easy explanation for why their child behaves the way he or she does, and unfortunately, science hasn't yet found that easy explanation.