From the anti-vaxers I've talked to, it's not so much the fear mongering, it's their distrust of scientific studies due to economic incentives.
Smart people especially know that it's relatively easy to lie with statistics and to generate studies with subtle selection bias.
If your premise is that most/all modern scientific studies are funded by drug companies and therefore cannot be trusted, then being anti-vax is still a stretch but you can at least see how it could be rationalized. Especially given the rich history of money suppressing/biasing scientific studies in the past: smoking, asbestos, j&j baby powder, round-up, etc.
Smart people especially know that it's relatively easy to lie with statistics and to generate studies with subtle selection bias.
If your premise is that most/all modern scientific studies are funded by drug companies and therefore cannot be trusted, then being anti-vax is still a stretch but you can at least see how it could be rationalized. Especially given the rich history of money suppressing/biasing scientific studies in the past: smoking, asbestos, j&j baby powder, round-up, etc.