In 1962, oral polio vaccine types 1 and 2, developed by Dr. Albert Sabin and grown in monkey kidney cell culture, were licensed for use by the U.S. Food and Drug Administration. The U.S. Surgeon General had approved Sabin’s poliovirus vaccine to be manufactured on a trial basis in August 1960.

Sabin had always believed that a live-virus oral polio vaccine, attenuated enough to produce a mild infection but weak enough not to cause harm, was the only way to stop polio. Many scientists also considered this live-virus vaccine to be preferential because it could be administered orally and mimic the way that the poliovirus enters and replicates in the body. His vaccine would contain all 3 types of poliovirus strains and he attenuated the virus by passing each one through the tissue of monkeys.