The LA Times has a good article on the history of autism/vaccine research.
They raise an interesting point at the end, which is that vaccines do not “cause autism” but we can’t prove that they never cause autism in anyone ever (and don’t currently have the knowledge of etiology to say how likely it is or isn’t that they never cause autism in anyone ever). So scientists continue to look to see whether there might be a tiny, highly susceptible population.
I’m sincerely hoping that what happens is that 1) they do find such a population and 2) it is identifiable, so that 1) anti-vaccine believers might focus on a tiny effect that really happens rather than a large effect that does not, and 2) vulnerable people will be identified and prohibited from taking the vaccine and non-vulnerable people will be identified and strongly encouraged to take the vaccine and ideally will. And then all autistic and non-autistic children are that much less likely to get deadly childhood diseases.