Max Theiler (mäks tīl´ər), 1899–1972, South African–American research physician, b. Pretoria, educated at the Univ. of Cape Town, St. Thomas's Hospital (London), and the London School of Tropical Medicine. Theiler's research on yellow fever, begun while he was connected with the department of tropical medicine of Harvard Medical School (1922–30), was continued at the Rockefeller Foundation, of which he became a staff member in 1930. He became known for his researches on yellow fever, encephalomyelitis, and other viruses associated with the tropics. For his work in developing a vaccine for yellow fever he was awarded the 1951 Nobel Prize in Physiology or Medicine.