What concerns me most is the basis on which the claim that they, or more specifically the disinfectants and adjuctants used (mercury and aluminium respectively), do not cause autism. There was a study that concluded that further research was needed to study the link between heavy metal poisoning (mercury) and autism, stataticians later criticized the conclusions and now use the same study to say that there is no correlation between the two. Leading health organizations like the WHO actually have replacing aluminium based adjutants from vaccines listed as a top priority. Getting single dose vaccines, as opposed to vials where several doses are drawn from, eliminates the need for the disinfectant; they are more expensive, and you are still getting adjutants, but I'd really rather not end up on one of those drug lawsuit commercials down the road so its worth it to me.