Orac talked about a comment which discussed how anti-vaccine activists are trying to save the environment. I hadn't quite grasped the horrors of vaccines until I read that comment. It's sad to think that the smallpox virus has almost been eradicated. It's also disturbing how close the polio virus came to suffering the same fate, only to be saved by the tireless efforts of anti-vaccine activists.
And yes, I'm being sarcastic, which I mention in case you're one of those people who think vaccines do not prevent disease at all and that it's part of some evil conspiracy.