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
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