Polio vaccine incidents reduced public confidence in polio vaccine leading to a drop in vaccination rates. At the same time that Salk was testing his vaccine, both Albert Sabin and Hilary Koprowski continued working on developing a vaccine using live virus. During a meeting in Stockholm to discuss polio vaccines in November 1955, Sabin presented results obtained on a group of 80 volunteers, while Koprowski read a paper detailing the findings of a trial enrolling 150 people. Sabin and Koprowski both eventually succeeded in developing vaccines. Because of the commitment to the Salk vaccine in America, Sabin and Koprowski both did their
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