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
Salk Institute for Biological Studies draw the best researchers in the world. Salk and Kahn – having both descended from Russian Jewish parents that had immigrated to the United States – had a deeper connection than just mere partners on an architectural project. The results of their connection is seen in the design that resulted from their collaboration. The original buildings of the Salk Institute were designated as a historical landmark in 1991. The entire site was deemed eligible by the California Historical Resources Commission in 2006 for listing on the National Register of Historic Places. The institute has three Nobel laureates on its faculty: