Unknown author · Public domain

André Michel Lwoff spent his career at the Pasteur Institute unraveling how certain viruses infect bacteria without immediately destroying them, identifying and naming the "provirus" mechanism by which a virus's genetic material integrates into its host and lies dormant before reactivating — a discovery that became foundational to molecular biology. He shared the 1965 Nobel Prize in Physiology or Medicine with François Jacob and Jacques Monod, his longtime collaborators at the Institute, for the work. He and his wife, microbiologist Marguerite Lwoff, published extensively together, and he was an outspoken opponent of capital punishment.