1796 English doctor Edward Jenner noticed that milkmaids who had gotten cowpox were protected from smallpox. He grabs a boy off the street and administers the very first vaccine to prove his theory. Where was the ethics committee? Quite possibly he saved the boys life it turns out, as it proves successful. The more deadly strain of smallpox killed 30% of those infected and left survivors badly scarred and disfigured. Global vaccination efforts by the World Health Organization has completely eradicated smallpox and to date it is the only human disease to be completely eradicated.