I used to spend time in an online antivax community because it was a good source of alternative health info. Some members had Phds and we're published authors.
Most people there had very negative personal experiences with vaccines. Either themselves or one of their children had a serious reaction.
It's known that some people have serious reactions. This isn't something made up by anti-vaxxers. But the current climate gets people with real problems treated as nutters who simply don't have a real medical issue.
When I was growing up, we counted success in terms of how many people got vaccinations, but there was no expectation it would ever be 100 percent. Now, we act like we "failed" to get 100 percent when we quote stats rather than counting the high percentage of vaccinated as a big success.
I think the root cause of the antivax movement is probably that we are leaving no room for those edge cases who have a genuine problem with vaccines, medically speaking. Those edge cases -- those people for whom this is a real problem -- seem to have concluded that the only way to protect their own right to choose is to make antivax the default norm instead of pro vax.
It's probably doomed because vaccines have proven to be beneficial to society as a whole. But if it is clear in your own mind that vaccines are a threat to your life, it readily becomes a hill you are willing to die on, so to speak.
I'm neither antivax nor pro vax. I think vaccines have their uses, but we need room for those edge cases to have the right to choose.
I get vilified by both camps because neither can tolerate a moderate position, which suggests to me they are both basically equally crazy. A reasonable person is aware that exceptions exist and that you have to have a system that makes allowances for that reality.