The plague didn't kill just dumb people. It killed anyone with the misfortune of being in proximity to rats, which is pretty much everyone in medieval Europe, aside from the very wealthy.
I mean...
Culling all carriers of a disease is already a viable and occasionally used method of eradicating a problem. The most recent account I can think of was Mad Cow in the uk where they killed over 300,000 cattle in the 80s and 90s. There was also something in New Zealand a few months ago that I don't remember the details on.
THE PLAGUE WAS CAUSED BY BACTERIA, NOT A VIRUS. YOU CAN'T VACCINATE AGAINST BACTERIA! That's what antibiotics are for! Even though they're starting to lose effect.
There are vaccines for some bacterial diseases, like meningitis, pneumococci, diphtheria, tetanus, whooping cough. They work in much the same way as vaccines against viruses.
More subtle but as idiotic: "All that panic over the swine/bird flu is just fear mongering for the benefit of big pharma". Maybe said flu killed only 20 people *because* the World Health Organization successfully contained it.
Culling all carriers of a disease is already a viable and occasionally used method of eradicating a problem. The most recent account I can think of was Mad Cow in the uk where they killed over 300,000 cattle in the 80s and 90s. There was also something in New Zealand a few months ago that I don't remember the details on.