Just stumbled over your post and wanted to answer.
Those anti-vaccine people belong to the part of society who don't know any better.
They don't understand how it works, they think you just shoot the germ into their kids' organism. That the germ is either dead or just simulated doesn't matter to them.
It's really sad that so many people have no idea about how their body works. You'd think school's biology lessons would give them at least an idea, but no.

(Sorry for mistakes, English isn't my native language)