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
Salk School of Science Perry and the vice/ assistant principal is Jennifer Goodwin. The school allows students to bring money to school and at lunch time, to go out and buy themselves lunch at a variety of delis and restaurants. The school shares its building with another school, P.S. 40 which owns most of the building. There is a gymnasium, a cafeteria which is shared between the schools, and 2 floors exclusive to Salk School of Science. Both are located near the top of the building. There are 3 entrances one to the left side of the building, one to the right and one