Poliomyelitis leading to large-scale trials in the then Belgian Congo and the vaccination of seven million children in Poland against serotypes PV1 and PV3 between 1958 and 1960. The second inactivated polio virus vaccine was developed in 1952 by Jonas Salk at the University of Pittsburgh, and announced to the world on 12 April 1955. The Salk vaccine, or inactivated poliovirus vaccine, is based on poliovirus grown in a type of monkey kidney tissue culture (vero cell line), which is chemically inactivated with formalin. After two doses of inactivated poliovirus vaccine (given by injection), 90 percent or more of individuals develop
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