I can guarantee most people like that don't believe in herd immunity
@PigglePuggle, or at the very least don't have a clue what it even is. The people pushing an anti-vax stance are the sort of people that prey on the ignorant and uninformed. I think someone like The Food Babe (I'm not linking to her stuff, it's not worth the free publicity) is a great example of this. She got ill, decided to treat herself by reading up on nutrition and food info and now peddles herself as a food guru trying to rid the world of "bad food", "toxic chemicals" and...you get the drift. Post anything critical of what she writes on Facebook or on her blog and the comment is deleted and you're blocked, no questions asked. She has herself an army of followers who claim critics are pushing a big pharma agenda, or a big government agenda, or a big "whatever they're upset with at the time" agenda.
It's dangerous, and her followers make it even more so. But she's exactly the type of person, with exactly the type of following, that people pushing an anti-vax agenda want. She also gets money for peddling products containing ingredients she calls "dangerous".