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
Jonas Salk Times", a few months after his vaccine announcement. The "Times" article noted, "at 40, the once obscure scientist ... was lifted from his laboratory almost to the level of a folk hero." He received a presidential citation, a score of awards, four honorary degrees, half a dozen foreign decorations, and letters from thousands of fellow citizens. His alma mater, City College of New York, gave him an honorary degree as Doctor of Laws. But "despite such very nice tributes", "The New York Times" wrote, "Salk is profoundly disturbed by the torrent of fame that has descended upon him. ... He