Jonas Salk laboratory. He later joined the National Foundation for Infantile Paralysis's polio project established by President Franklin D. Roosevelt. Extensive publicity and fear of polio led to much increased funding, $67 million by 1955, but research continued on dangerous live vaccines. Salk decided to use the safer 'killed' virus, instead of weakened forms of strains of polio viruses like the ones used contemporarily by Albert Sabin, who was developing an oral vaccine. After successful tests on laboratory animals, on July 2, 1952, assisted by the staff at the D.T. Watson Home for Crippled Children, Salk injected 43 children with his killed-virus
Jonas Salk assembled, devoted himself to this work for the next seven years. The field trial set up to test the Salk vaccine was, according to O'Neill, "the most elaborate program of its kind in history, involving 20,000 physicians and public health officers, 64,000 school personnel, and 220,000 volunteers." Over 1,800,000 school children took part in the trial. When news of the vaccine's success was made public on April 12, 1955, Salk was hailed as a "miracle worker" and the day almost became a national holiday. Around the world, an immediate rush to vaccinate began, with countries including Canada, Sweden, Denmark, Norway,