Because they have this podcast with one doctor and that PDF from a think tank that gives them all the info they need. "This guy who worked at Pfizer or who worked on vaccines has the REAL truth that the other 99.9% of scientists won't acknowledge!"
Like... how do you convince that person to get a vaccine? They won't listen to 99.9%.

And leave the conspiratorial anti-vaxxers aside for a moment-- what about the normal folks who aren't QAnon or anything, they just "don't really trust the vaccine"? There's endless material online from an overwhelming consensus of doctors and scientists. So if they still trust their gut over the vast majority of the field of experts, then they're either alarmingly incurious or not being honest with themselves about the forces driving their decision.

Shit, they booed Trump the other day when even *he* said to go get a vaccine and a booster.

Their minds are made up. They know the hidden truth about the world that all doctors and scientists are conspiring to conceal, or, perhaps less forgivably, they simply don't care about any of this. So while I have relative compassion for many of those who chose not to get the vaccine, through lack of access to education or through personal trauma or through whatever else may have led them down this path... I also find the impulse in those who now have no compassion for the anti-vax set completely understandable. Unvaccinated people are more likely to be the hosts for mutations and subsequent variants (if you're skeptical, take five minutes of Google searching, you'll find a dozen sources). Delta, Omicron, and to-be-determined variants, variants that can break through existing vaccines, cause further societal disruption, and threaten the lives of ourselves and our loved ones. The depth and breadth of general compassion for humanity has its limits.