Karl Landsteiner &
Erwin Popper discovered the polio virus
The U.S. used Dr. Salk's 1953 killed polio vaccine from '55-'62. From '63-'99, the U.S. used Dr. Sabin's 1962 live oral vaccine. It's still used where polio is endemic. The U.S. has used the Salk vaccine since 2000. Withered limbs from polio have been documented since early man: note the Egyptian priest's withered left leg. Be wise, immunize!