Prior to Covid, the antivaxx scene was vaguely left-and-green oriented, biomoms, vegans and other "very natural" people; you would expect them to vote for Greens or even more alternative parties. This changed abruptly and now the antivaxx scene is mostly rightwing, but the common base is still the same distrust.
I wonder if this is the price we pay for radical informational transparency. Nowadays, democratic countries with reasonable freedom of press cannot really prevent their own fuckups from surfacing in the worst possible way. Some people react by complete rejection of anything that comes from "official" channels and become ripe for manipulation from other actors.