Polio vaccine

Two polio vaccines are used throughout the world to combat polio. The first was invented by Jonas Salk, and first tested in 1952 and announced to the world by Salk on March 26, 1953. It consists of an injected dose of killed polio virus. Albert Sabin[?] produced a cheaper and more effective oral polio vaccine in 1962.

Polio vaccination site http://www.whale.to/vaccines/polio4