jan 1, 1796 - Edward Jenner and Variolation (Smallpox)
*Variolation: purposely infect with smallpox to create a mild infection to create immunity
*30% mortality rate for smallpox vs 1-2% mortality rate from variolation
*Jenner observed that milk maids that had cowpox did not contract smallpox
*Jenner experimented with a boy and infected him with cowpox. After retesting with smallpox, the boy didn't get it.
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