By Ginny A. Roth
Poliomyelitis (Polio), a disease that attacks the nervous system and causes paralysis, was a widespread epidemic in the United States during the 19050s. On March 26, 1953, Jonas Salk, an American researcher and Virologist, announced that he had successfully tested a vaccine against the virus that causes polio. This first successful polio vaccine, known as inactivated poliovirus vaccine (IPV) or Salk vaccine, contained the killed virus and was given by injection. In 1954, massive testing of the vaccine in clinical trials was used on nearly two million school children nationwide. The vaccine was announced to be safe and effective in 1955, the same year the vaccination was licensed, leading to the wide distribution of the vaccine to children in the United States. In the following years, after a nationwide inoculation campaign promoted by the National Foundation for Infantile Paralysis, the annual number of polio cases fell from 35,000 in 1953 to 5,600 by 1957. By 1961 only 161 cases were recorded in the United States, where the disease has since been eradicated.