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
David Bruce (microbiologist) tsetse fly vector, of African trypanosomiasis ("sleeping sickness"). He was Surgeon-General for the duration of the First World War from 1914–19 at the Royal Army Medical College, Millbank, London. "Brucella" is the genus and Brucellaceae is the family of the bacteria which was named after him, in recognition of his discoveries. "Brucella melitensis" is the cause of undulant fever in man and of abortion in goats. It is usually transmitted by goat's milk. "Trypanosoma brucei", the cause of sleeping sickness, is also named after him. Bruce was elected a Fellow of the Royal Society (FRS) in 1899. He served as