Contrary to the era’s prevailing scientific opinion, Salk believed his vaccine, composed of “killed” polio virus, could immunize without risk of infecting the patient. After animal testing, Salk administered the vaccine to volunteers who had not had polio, including himself, his lab scientist, his wife and their children. All developed anti-polio antibodies and experienced no negative reactions to the vaccine.
In 1954, national testing began on one million children, ages six to nine, who became known as the Polio Pioneers. On April 12, 1955, the results were announced: the vaccine was safe and effective. In the two years before the vaccine was widely available, the average number of polio cases in the U.S. was more than 45,000. By 1962, that number had dropped to 910. Hailed as a miracle worker, Salk never patented the vaccine or earned any money from his discovery, preferring it be distributed as widely as possible.
Although the Salk polio vaccine was superseded in the United States by the oral live-virus vaccine developed by American virologist Albert B. Sabin (1906-1993), the Salk vaccine was still used in many countries of the world for a number of years.
Today it is the Sabin oral vaccine that vaccinates children against Polio. However Salk was the first with his successful 'killed virus' research.
