William Pollack (February 26, 1926 – November 3, 2013) was a British-born American immunologist who developed the Rho(D) immune globulin vaccine against Rh disease, a leading cause of erythroblastosis fetalis. Pollack co-developed the vaccine, also known by the RhoGAM brand name, which is given to pregnant women to prevent Rh disease, with Dr. Vincent Freda and Dr. John G. Gorman of Columbia-Presbyterian Medical Center. Pollack's vaccine, introduced in 1968, virtually eliminated cases of Rh disease in developed countries. Prior to the RhoGAM vaccine, Rh disease was responsible for approximately 10,000 infant deaths in the United States annually.