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 memorial to Jonas Salk, a golden engraving lies on the floor at the entrance to the institute: "Hope lies in dreams, in imagination and in the courage of those who dare to make dreams into reality." Francis Crick held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute. His later research centered on theoretical neurobiology and attempts to advance the scientific study of human consciousness. He remained in this post at the Salk Institute until his death in 2004. From 22–27 April 2010, the Salk Institute hosted glass sculptures by artist Dale Chihuly to celebrate 50 years