Albert Sabin a vaccine to prevent or mitigate the illness. The Sabin vaccine is an oral vaccine containing weakened forms of strains of polio viruses. In 1955, Salk's "killed" vaccine was released for use. It was effective in preventing most of the complications of polio, but did not prevent the initial intestinal infection. The Sabin vaccine is easier to give than the earlier vaccine developed by Salk in 1954, and its effects last longer. Sabin first tested his live attenuated oral vaccine at the Chillicothe Ohio Reformatory in late 1954. From 1956–1960, he worked with Russian colleagues to perfect the oral vaccine
By His Bootstraps By His Bootstraps "By His Bootstraps" is a 20,000 word science fiction novella by American writer Robert A. Heinlein. It plays with some of the inherent paradoxes that would be caused by time travel. The story was published in the October 1941 issue of "Astounding Science Fiction" under the pen name Anson MacDonald; the same issue has "Common Sense" under Heinlein's name. "By His Bootstraps" was reprinted in Heinlein's 1959 collection "The Menace From Earth", and in several subsequent anthologies, and is now available in at least two audio editions. Under the title "The Time Gate", it was also included