Two polio vaccines
are used throughout the world to combat polio
. The first was invented by Jonas Salk
, and first tested in 1952 and announced to the world by Salk on March 26
. It consists of an injected dose of killed polio virus. Albert Sabin produced a cheaper and more effective oral polio vaccine in 1962. The two vaccines have eliminated polio from most of the countries in the world and reduced early cases from hundreds of thousands per year to only 1000 worldwide in 2001.