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) David Bruce (microbiologist) Major-General Sir David Bruce (29 May 1855 in Melbourne – 27 November 1931 in London) was a Scottish pathologist and microbiologist who investigated Malta fever (later called brucellosis in his honour) and African trypanosomiasis (sleeping sickness in humans and nagana in animals). He discovered a protozoan parasite transmitted by insects, later named "Trypanosoma brucei" after him. Working in the Army Medical Service and the Royal Army Medical Corps, his major scientific collaborator was his microbiologist wife Mary Elizabeth Bruce ("née" Steele), with whom he published more than thirty technical papers. Bruce was born in Melbourne, Australia to