Dr. Jonas Salk invented the polio vaccine, a discovery that he wrote about in the 1953 in The Journal of the American Medical Association. Nationwide testing of his vaccine began in 1954, and over the next few years, polio infections fell dramatically.
Dr. Salk's vaccine was made from killed polio viruses, and Dr. Salk was even willing to test it on his own family and himself. Polio had long been a cause of paralysis and death worldwide, with children especially susceptible. It was particularly bad in the United States during the early 1950s. By 1957, the number of cases had dropped almost 80 percent from just two years earlier. As of 2014, polio is almost completely gone in the United States, and the number of cases worldwide are extremely diminished.