Did not George Washington ban smallpox vaccinations because some of the troops were dying after getting vaccinated?
In those days, you took a healthy man with a weak case of smallpox, stuck a needle into one of his sores, then pricked a healthy person to give them immunity. Sometimes it did not work.
Pastor Johnathan Edwards died of such a vaccination.
Did he? Saw a discussion on BookTV a year or so ago on vaccinations in Colonial America, and according to the author, GW told his stepson to ignore Martha, and get the inoculation.
I don't think the troop thing came up.
Washington had survived a fairly bad case of smallpox as a young man. My understanding is he supported variolation, ordering it for the Continental army in 1775. Maybe there were incidences of it being done improperly that lead to temporary exceptions; I don't know about any. Early in the war we lost our chance to conquer Quebec due to smallpox ravaging our forces. I'm still unsure whether to count that as a plus or a minus for smallpox. But I don't think smallpox had near as much effect later in the war.