On March 26, 1953, American medical researcher Dr. Jonas Salk reported that he had successfully tested a vaccine against poliomyelitis, the virus that causes the crippling disease of polio. Salk's procedure was to kill several strains of the virus and inject the benign viruses into a healthy person's bloodstream. The person's immune would then create antibodies designed to resist future exposure to poliomyelitis. Polio, a disease that mainly affects children, attacks the nervous system and can cause paralysis. Since the virus is easily transmitted orally, epidemics were commonplace in the first decades of the twentieth century. In 1950 alone there were 33,344 reported cases. Though children and especially infants are among the worst affected, adults are often afflicted too, including Franklin D. Roosevelt who in 1921 was stricken with polio and partially paralyzed. In April 1955, two years after Dr. Salk announced his polio vaccine, it was approved for use in the United States. On...