University of Pittsburgh had begun immunization experiments in monkeys using dead polio virus. Soon, however, Salk began to test inoculations in paralyzed polio patients and by 1953 human trials among the general population were initiated. By the spring of the following year, the largest controlled field trials in medical history were underway, and by 1955 the vaccine developed by Salk and his researchers was declared effective. By 1962, Salk's vaccine had reduced the incidence of polio in the United States by 95 percent. The breakthroughs in immunology and vaccine development at Pitt by Salk and his team are considered one of the most
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