Yup, I’ve said this for years. To antivaxxers, those old diseases are boogeymen. They legitimately don’t believe the diseases are bad, because “well people survived for thousands of years before” (survivorship bias) and the fact that they’ve never been personally affected by it.

They never lost a childhood friend to measles. They never saw entire hospital wings full of kids in iron lungs because of polio. They never watched a friend or family member go deaf because of a childhood case of mumps. They never had a brother, uncle, etc have to come to terms with being unable to have kids, because a childhood case of mumps left them sterile.

But you know what is real to the antivaxxers? Autism. Everyone knows (or has seen) someone who was severely autistic. It doesn’t matter if the link between autism and vaccines is fake; the imagined threat of autism is a bigger threat in their minds than the very real threat of these diseases.