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 units set on a bluff overlooking the Pacific, Dr. Salk holds the titles of founding director and resident fellow. His own laboratory group is concerned with the immunologic aspects of cancer and the mechanisms of autoimmune disease, such as multiple sclerosis, in which the immune system attacks the body's own tissues. In an interview about his future hopes at the institute, he said, "In the end, what may have more significance is my creation of the institute and what will come out of it, because of its example as a place for excellence, a creative environment for creative minds." Francis