Baruch S. Blumberg
Baruch Samuel Blumberg (born 1925) is a American scientist and recipient of the 1976 Nobel Prize in Medicine for "discoveries concerning new mechanisms for the origin and dissemination of infectious diseases." Blumberg identified the Hepatitis B virus, and later developed the diagnostic test and vaccine for it.
Blumberg served as Master of Balliol College from 1989 to 1994.