Polio vaccine attenuated vaccine strains. In 1958, the National Institutes of Health created a special committee on live polio vaccines. The various vaccines were carefully evaluated for their ability to induce immunity to polio, while retaining a low incidence of neuropathogenicity in monkeys. Large-scale clinical trials performed in the Soviet Union in late 1950s to early 1960s by Mikhail Chumakov and his colleagues demonstrated safety and high efficacy of the vaccine. Based on these results, the Sabin strains were chosen for worldwide distribution. Fifty-seven nucleotide substitutions distinguish the attenuated Sabin 1 strain from its virulent parent (the Mahoney serotype), two nucleotide substitutions
The Stolen Invention Deering's invention and is greatly impressed with it. Cobleigh offers Deering a small amount of money for the invention, but Deering refuses to accept it. Then Cobleigh, having failed to get his invention by fair means, determines to secure it by foul. He drugs Deering, and the result of the poison is to make the inventor temporarily insane. While in this condition, Cobleigh has Deering transferred to an insane asylum. Then he forges the inventor's name to the bill of sale and thinks that his crime will never be discovered. Deering's daughter, Grace, failing to induce her sweetheart, Tom Reynolds,