Born June 13, 1870; died on April 6, 1961 at the age of 90.
Jules Jean Baptiste Vincent Bordet was a Belgian bacteriologist and immunologist who discovered complement, a protein complex that causes foreign cells to be destroyed in the immune response in the blood. It also isolated a number of other pathogenic bacteria. He received the Nobel Prize in Physiology or Medicine in 1919 for discovering immune factors in blood serum. This development was vital for the diagnosis and treatment of many dangerous infectious bacterial diseases.