This isn't just an American issue. In Pakistan UN health workers were killed, because the local population believed there was a conspiracy to decrease population numbers with poisonous vaccinations that cause diseases.
Yeah... the thing with Pakistan is that the US seriously fucked up by piggybacking their search for Osama bin Laden onto a fake vaccination drive put together by the CIA.
I mean, yeah, they found bin Laden. Huzzah. They also set back vaccination efforts there for probably decades by actually engaging in the kind of behavior that these conspiracy theories think is going on.
Massive fuck-up.
Scientific American on the subject: http://www.scientificamerican.com/article/how-cia-fake-vaccination-campaign-endangers-us-all/