When Baruch Samuel Blumberg was notified on October 14, 1976 that he was a co-winner of the Nobel Prize for physiology or medicine, he made a humorous and low-key comment to the New York Times: "I'm especially pleased that someone from Philadelphia won. It's appropriate in the Bicentennial year and makes up in part for the Phillies not making it to the World Series." But there was nothing low-key about the research Blumberg had done to win the prize. In 1963 he had discovered a protein in the blood of Australian Aborigines, the so-called Australia antigen, which he determined to be part of the hepatitis B virus. This discovery has led to the introduction of blood screening programs as well as a successful vaccine against this disease, which has a mortality rate of up to 15 per cent.

Blumberg was born on July 28, 1925, in New York City, one of three children of...