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
Albert Sabin in the U.S. Army Medical Corps and helped develop a vaccine against Japanese encephalitis. Maintaining his association with Children's Hospital, by 1946, he had also become the head of Pediatric Research at the University of Cincinnati. At Cincinnati's Children's Hospital, Sabin supervised the fellowship of Robert M. Chanock, whom he called his "star scientific son." Sabin went on a fact-finding trip to Cuba in 1967 to discuss with Cuban officials the possibility of establishing a collaborative relationship between the United States and Cuba through their respective national academies of sciences, in spite of the fact that the two countries did