I hear this meme sometimes, that anti-vaxxers and others "prefer a dead child to an autistic one," and I think it fundamentally doesn't represent their thought process at all.

The far-more common sentiment that I see among anti-vaxxers is that the risk of death from childhood diseases like chicken pox are either zero or close-to-it, and that the risk of receiving autism from the vaccine is at least one-in-ten. These numbers aren't true, of course, but in their minds, they're weighing a negligible-chance of terrible outcome against a moderate chance of bad outcome.

I'm sure there's a few extremists of course, who would say they prefer a dead child to an autistic one (same as how some parents feel about gay kids), but it does not represent most of the people in these movements.