Frank Macfarlane Burnet

Frank Macfarlane Burnet (1899-1985) was an Australian virologist and immunologist whose clonal selection theory reshaped how medicine understands the body's own defenses against disease. Working chiefly at the Walter and Eliza Hall Institute in Melbourne, Burnet proposed that the immune system already carries, before any infection occurs, an enormous diverse population of cells each primed to recognize one specific foreign substance, and that exposure simply triggers the matching cells to multiply, a model that explained both how the body distinguishes its own tissue from invaders and how vaccination and immune memory work. He also predicted acquired immune tolerance, the principle later exploited in organ transplantation to stop a recipient's body rejecting a donor organ, and shared the 1960 Nobel Prize in Physiology or Medicine with Peter Medawar for that work. His clonal selection framework remains a foundational teaching model in immunology and infectious-disease medicine today.