Crimean Tatars catapult plague-infected corpses into Italian trade settlement.
Spanish conquistadors use biological warfare used against Native peoples.
Blankets infected with smallpox deliberately given to Native Americans, causing widespread epidemics. Japanese military discovered to have conducted biological warfare experiments on POWs, killing 3000. U.S. shields officers in charge from war crimes trials, in return for data. Army begins secret tests of biological agents in U.S. cities. San Francisco disease outbreak matching Army bacteria used on city.