Oral Polio Vaccine

The oral polio vaccine was developed by Albert Sabin and his team of researchers in 1961 by passing the virus repeatedly through monkey kidney cells. These attenuated strains were able to induce immunity.

The OPV is administered in three oral doses at monthly intervals. At the initial dose, only one serotype replicates successfully and achieves immunity, and the two subsequent doses induce immunity against the two remaining serotypes.
 
However, the OPV vaccine can sometimes, but rarely, induce a vaccine related case of virulent poliomyelitis (VAPP). This VAPP can be transmitted to susceptible individuals within a community.