(1914-1995).American medical researcher and educator. In 1947, he joined the staff of the University of Pittsburgh as director of the Virus Research Laboratory of the School of Medicine. While continuing his work on influenza, he became interested in finding a way to prevent poliomyelitis. He developed the Salk vaccine, made by cultivating three strains of the polio virus separately in monkey tissue. Thanks in large measure to the Salk vaccine the dreaded “infantile paralysis” disease has largely become a thing of the past.