Viral Phenom
I would have no problem with anti-vaxxers if they only harmed themselves. Even, maybe if it were only their children who were at risk. Stupidity should have consequences and it should not be passed on to another generation.
The problem comes in when these mucking forons actively harm others who do not ignore reality, who behave reasonably, and who just have the misfortune to find themselves in said forons' proximity.
I could see proposing that anti-vaxxers all be sequestered somewhere reserved for them, where they can see how their take on imaginary medical wisdom will play out.