Germ warfare was a strategy used in many colonisation and war efforts. This includes North American Indigenous populations (there are reports of blankets from smallpox-infected corpses being deliberately distributed in the late 1700s); bodies of dead animals or humans being thrown into water supplies during warfare in Italy in the 12th century; and saliva from rabid dogs or the blood of leprosy patients being used by the Spanish against French enemies in Italy in the 15th century.
Biological weapons are a disgrace to biology. Most biologists have not wanted to talk or even thing about them. Some naively have claimed that bioweapons do not work and are nothing to worry about. The physicists lost their innocence when the first nuclear bomb went of in 1945. The biologists will lose their innocence when the first biological weapon spreads through the human species.