Jonas Salk he had hoped and he found the rules imposed by the university restrictive. In 1948, Harry Weaver, the director of research at the National Foundation for Infantile Paralysis, contacted Salk. He asked Salk to find out if there were more types of polio than the three then known, offering additional space, equipment and researchers. For the first year he gathered supplies and researchers including Julius Youngner, Byron Bennett, L. James Lewis, and secretary Lorraine Friedman joined Salk's team, as well. As time went on, Salk began securing grants from the Mellon family and was able to build a working virology
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