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 known the world over, Salk, in the public's eye, had a superstar aura. Airplane pilots would announce that he was on board and passengers would burst into applause. Hotels routinely would upgrade him into their penthouse suites. A meal at a restaurant inevitably meant an interruption from an admirer, and scientists approached him with drop-jawed wonder as though some of the stardust might rub off." For the most part, however, Salk was "appalled at the demands on the public figure he has become and resentful of what he considers to be the invasion of his privacy", wrote "The New York