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
Vaccine: The Controversial Story of Medicine's Greatest Lifesaver possess the virus. It then describes how this vaccine was only slightly different from the type invented by Edward Jenner two centuries earlier, which was so successful that smallpox became the first and only disease to ever be eradicated. Vaccine developers profiled in the book include Jonas Salk (p. 188) and Maurice Hilleman (p. 238). Allen, later in the book, describes the controversy over vaccines and autism and the founding of SafeMinds, writing, "The vaccines-cause-autism mindset was the product of a set of assumptions that were impossible to completely prove or disprove." (p. 374) It also discusses how preliminary study