Polio vaccine polio and post-polio syndrome. In the United States, vaccine is administered along with the tetanus, diphtheria, and acellular pertussis vaccines (DTaP) and a pediatric dose of hepatitis B vaccine. In the UK, IPV is combined with tetanus, diphtheria, pertussis, and "Haemophilus influenzae" type b vaccines. OPV is an attenuated vaccine, produced by the passage of the virus through nonhuman cells at a subphysiological temperature, which produces spontaneous mutations in the viral genome. Oral polio vaccines were developed by several groups, one of which was led by Albert Sabin. Other groups, led by Hilary Koprowski and H.R. Cox, developed their own
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