ON THIS DAY IN 1860, BACTERIOLOGIST WALDEMAR HAFFKINE WAS BORN: If he had only been willing to convert from Judaism to Christianity, he could have had an academic career in the Russian Empire where he was born. But Haffkine was not the type to bend to that kind of pressure. Fortunately for him and for humankind, he was able to secure a position at the Pasteur Institute in Paris, where he developed vaccines for cholera and bubonic plague. How did he know that his vaccines were safe? He tested them on himself.