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
Salk Institute for Biological Studies draw the best researchers in the world. Salk and Kahn – having both descended from Russian Jewish parents that had immigrated to the United States – had a deeper connection than just mere partners on an architectural project. The results of their connection is seen in the design that resulted from their collaboration. The original buildings of the Salk Institute were designated as a historical landmark in 1991. The entire site was deemed eligible by the California Historical Resources Commission in 2006 for listing on the National Register of Historic Places. The institute has three Nobel laureates on its faculty: