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
Jonas Salk austere", wrote "The New York Times", "Salk the man is a person of great warmth and tremendous enthusiasm. People who meet him generally like him." A Washington newspaper correspondent commented, "He could sell me the Brooklyn Bridge, and I never bought anything before." Award-winning geneticist Walter Nelson-Rees called him "a renaissance scientist: brilliant, sophisticated, driven ... a fantastic creature." He enjoys talking to people he likes, and "he likes a lot of people", wrote the "Times". "He talks quickly, articulately, and often in complete paragraphs." And "He has very little perceptible interest in the things that interest most people—such as