Researched
Polio vaccines
Jonas Salk's injected vaccine (1955) and Albert Sabin's oral one (1961) pushed polio close to eradication; wild cases fell by over 99% since 1988.
Open in the interactive tree →Salk's 1954 field trial enrolled about 1.8 million US children, one of the largest medical trials ever. John Enders's 1949 method of growing poliovirus in cell culture had made large-scale vaccine production possible.