The anti-vaccine movement started early on with the first vaccination. They have latched onto the allegeded autism link as their cash cow. They realize it is an emotional issue and that no one really knows how autism occurs therefore you cannot conclusively say “It wasn’t the vaccines.” They prey on parents of autistic children to get them to join their cause. They have already decided vaccines are bad for other reasons, but this a hook for new recruits so to speak.
You can talk all you want about how rates of certain diseases have gone down since vaccines where introduced but they will say, with a straight face, it is all coincidental, vaccine do nothing but harm, any studies saying otherwise are flawed (or that actualy fraud occured before results were published) and are part of a master conspiracy. If you pair this with some arguably shady past behavior by both the vaccine manufacturers and the CDC, you give some people grounds to believe their arguments. If you add in an emotional parent, distraught about a recent and seemingly out of the blue diagnosis of autism, they are probably more prone to go along with the theory.
This is the same logic that has given rise to out of control OB lawsuits. For example no one know exactly how cerebal palsey comes about but there is speculation that something goes wrong during delivery. A jury gets teary eyed hearing parents testify about their child’s life and so they award them large sums of money, regardless of whether any hard facts can be introduced to prove the doctors should have known and should have pursued and different and specific course of action. Sure their are negligent OBs, but their are also situations when a good doctor really couldn’t have known that something tragic was going to happen or couldn’t have prevented it even if he knew. He may have safely delivered 1000’s of healthy baby but, by golly, he’ll pay for this one who has problems(well, his insurance will.)
Anyhow, this is why I think the parents of autistic children will win a large sum in their case against the vaccine manufacturers. Such is the nature of the American legal system.