What I wrote the first time was closer to the truth. This is what I read.
Marian + + + + + + + + [JAMA is the Journal of the American Medical Association] http://jama.ama-assn.org/issues/v281n22/ffull/jst90000.html HISTORY AND POTENTIAL AS A BIOWEAPON Smallpox probably was first used as a biological weapon during the French and Indian Wars (1754-1767) by British forces in North America. Soldiers distributed blankets that had been used by smallpox patients with the intent of initiating outbreaks among American Indians. Epidemics occurred, killing more than 50% of many affected tribes. With Edward Jenner's demonstration in 1796 that an infection caused by cowpox protected against smallpox and the rapid diffusion worldwide of the practice of cowpox inoculation (ie, vaccination), the potential threat of smallpox as a bioweapon was greatly diminished.
