When was the first oral polio vaccine introduced?

Albert Sabin’s oral polio vaccine was licensed in 1961 and quickly became widely used because it was easy to administer by mouth. It helped interrupt person-to-person transmission more effectively in many settings than the injectable vaccine alone. Because it was inexpensive and practical, it became especially important in mass immunization campaigns worldwide. Together with Salk’s vaccine, it helped bring polio close to eradication.