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.
... former's unfaithfulness. In Moscow, Anna meets and secures the admiration of Count Vronsky to the jealously of Dolly's sister Katarina (Kitty) whom he has previously been ...