Global Polio Eradication,The Journey So Far.

: The Global Polio Eradication Initiative (GPE I), since its launch in 1988 has achieved more than 99% reduction in polio cases globally, using oral polio vaccine (OPV). Currently only two countries (Pakistan and Afghanistan) have not been able to stop transmission of wild poliovirus (wPV). In this article, we discuss some of the challenges faced by these two countries. The lessons learnt from the tremendous public health success stories of India and Nigeria are also highlighted. Reintroduction of wPV in the polio-free areas remains a valid risk globally and some recent examples are discussed. Inactivated polio vaccine (IPV) is the most accepted risk-mitigation strategy to secure a polio-free world from both wPV and circulating vaccine derived poliomyelitis (VDPV). The challenges related to switch from trivalent to bivalent OPV and introduction of IPV in 156 countries using trivalent OPV, are also highlighted.