Cold War tensions and the polio vaccine was the first polio vaccine to receive approval of the U.S. government, and was used until 1961 in America, when the Sabin vaccine was recommended to replace it. Albert Sabin, a virologist who publicly disagreed with Salk and his killed vaccine, worked on creating a vaccine with live, attenuated vaccines. Despite Cold War tensions, in January, 1956 Mikhail Chumakov, the director of Moscow's Polio Research Institute, his wife and colleague Marina Voroshilova, and Anatoli Smorodentsev, traveled to the U.S. in order to study the Salk vaccine and visited the laboratory of Albert Sabin. With the clearance of the FBI, Sabin
Jonas Salk artists have joined the scientists to achieve an understanding of man in all his physical, mental and spiritual complexity. Such interchanges might lead, he would hope, to a new and important school of thinkers he would designate as biophilosophers." Salk told his cousin, Joel Kassiday, at a meeting of the Congressional Clearinghouse on the Future on Capitol Hill in 1984 that he was optimistic that ways to prevent most human and animal diseases would eventually be developed. Salk said people must be prepared to take prudent risks, since "a risk-free society would become a dead-end society" without progress. Salk describes