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
For the Term of His Natural Life (1908 film) For the Term of His Natural Life (1908 film) For the Term of His Natural Life is a 1908 Australian silent film based on the 1874 novel by the same name by Marcus Clarke. The film is an adaptation of MacMahon's stage adaptation of the novel. It was the fourth Australian feature ever made and is considered a lost film. The 1908 film was the first screen adaptation of Clarke's novel, which was also later filmed in 1911, as a silent film known as "The Life of Rufus Dawes", 1927, again as a silent film, and the most expensive produced