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 it came into use in 1955. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Salk preferred not to have his career as a scientist affected by too much personal attention, as he had always tried to remain independent and private in his research and life, but this proved to be impossible. "Young man, a great tragedy has befallen you—you've lost your anonymity", the television personality Ed Murrow said to Salk shortly after the onslaught of media attention. When Murrow asked him, "Who owns this patent?", Salk