Polio vaccine The results of the field trial were announced 12 April 1955 (the tenth anniversary of the death of President Franklin D. Roosevelt, whose paralytic illness was generally believed to have been caused by polio). The Salk vaccine had been 60–70% effective against PV1 (poliovirus type 1), over 90% effective against PV2 and PV3, and 94% effective against the development of bulbar polio. Soon after Salk's vaccine was licensed in 1955, children's vaccination campaigns were launched. In the U.S, following a mass immunization campaign promoted by the March of Dimes, the annual number of polio cases fell from 35,000 in 1953
Jonas Salk two younger brothers, Herman and Lee, a renowned child psychologist. The family moved from East Harlem to 853 Elsmere Place, the Bronx, with some time spent in Queens where he resided at 439 Beach 69th Street, Arverne, New York. When he was 13, Salk entered Townsend Harris High School, a public school for intellectually gifted students. Named after the founder of City College of New York (CCNY), it was, said Oshinsky, "a launching pad for the talented sons of immigrant parents who lacked the money—and pedigree—to attend a top private school." In high school "he was known as a perfectionist