On 23rd February 1954, the first mass inoculation against Polio is conducted in Pittsburgh, Pennsylvania.The first polio vaccine, known as inactivated poliovirus vaccine (IPV) or Salk vaccine, was developed in the early 1950s by American physician Jonas Salk. This vaccine contains a killed virus and is given by injection.In the 1960s a second type of polio vaccine, known as oral poliovirus vaccine (OPV) or Sabin vaccine, named for its inventor American physician and microbiologist Albert Sabin, was developed.
