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
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