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
Grass for His Pillow before the pass is closed by snow. Once Spring thaws the snow, Kaede excuses herself from Fujiwara, stating her intention to visit Arai, her overlord, to discuss her future. He reluctantly agrees, and she travels via Terayama, as she has heard that Takeo is there. They meet, and as Takeo is under a death sentence from the Tribe, Kaede sends Shizuka and Kondo away. Against advice, Takeo and Kaede marry at Terayama. Grass for His Pillow Grass for His Pillow is the second novel in Lian Hearn's popular Tales of the Otori trilogy, published in 2003. The events in the