PHOTOS: Vaccine History Repeats Itself — Sometimes

Vaccines delivered by drones and by burros. People who shout about the danger of vaccines and refuse to get a jab. Public health campaigns to convince the vaccine hesitant. Public criticism of a failure to provide vaccines for lower-income countries and marginalized populations.

These are all part of the unprecedented world vaccination campaign now going on.

They're also the hot-button topics that go back to the very first vaccine — for smallpox in 1796.