Jonas Edward Salk (October 28, 1914 - June 23, 1995), born in New York City, was an American virologist and medical researcher. A graduate of City College of New York and New York University School of Medicine, in 1947, Salk accepted a professorship at the University of Pittsburgh School of Medicine, where he undertook a project to determine the number of different types of poliovirus and, eventually, develop a vaccine against polio.