Technological and industrial history of 20th-century Canada Blood tests would become increasingly sophisticated in the coming years. The electroencephalograph, used for the diagnosis of neurological disorders was introduced in major Canadian medical institutions in the late forties. The techniques for the mass production and distribution of vaccines and for the mass public inoculation were introduced during these years. Polio was a disease that affected large numbers of Canadian children during the first part of the 20th century. In the US, research by Dr. Jonas Salk in the late 1940s led to the discovery of vaccine for the prevention of this disease. However, there was no technique for
Cold War tensions and the polio vaccine flew to Leningrad in June, 1956. As a result of a cooperation of Sabin and Chumakov in Leningrad, Sabin was able to test his attenuated vaccine when funding in America was declined. While Sabin was working behind the Iron Curtain, the Sabin-Chumakov vaccine was determined to be safe and effective. Cold War tensions caused Western scientists to refuse the reports from the Russians about the effectiveness of the Sabin vaccine. However, mass vaccinations of Sabin's vaccine spread throughout Eastern Europe from 1960–1963. Just as some Soviet virologists did not trust the Western Salk vaccine, Americans had similar reservations about the