I don’t know if that’s how it works, but if it were, it should at least work in reverse. That is, someone watching anti-vax videos to support their assumptions might be exposed to the actual benefits from a video of the opposing view, and the benefits of vaccinations should be the stronger argument.
But I don’t really believe that people go into the internet with a malleable viewpoint. They start with an assumption and look for those who will affirm it.
If you’re a young earth creationist, you’re not going to be swayed by the occasional exposure to scientific accounts of the Pleistocene era. You’re just going to hang out with people with the same views to reinforce what you already believe and ignore all evidence to the contrary as the stuff of fantasy.
