Vaccine controversies new vaccines. Such incidents and others ensured that any untoward results concerning vaccination and related procedures received continued publicity, which grew as the number of new procedures increased. In 1955, in a tragedy known as the Cutter incident, Cutter Laboratories produced 120,000 doses of the Salk polio vaccine that inadvertently contained some live polio virus along with inactivated virus. This vaccine caused 40,000 cases of polio, 53 cases of paralysis, and five deaths. The disease spread through the recipients' families, creating a polio epidemic that led to a further 113 cases of paralytic polio and another five deaths. It was
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,