Progress towards global polio eradication.

Twelve years after the global polio eradication goal was set, polio cases have declined by more than 95% world-wide. Polio immunization campaigns have been conducted in every endemic country with as many as 470 million children immunized per year. Intense wild poliovirus transmission is now limited to South Asia and sub-Saharan Africa. To achieve eradication at the earliest possible date, immunization campaigns are being intensified in the remaining endemic countries. Major programmatic challenges include reaching vulnerable children in areas with armed conflict and ensuring full financial and political support for the initiative. With global eradication imminent, WHO is preparing for post-eradication issues: containment of polioviruses, certification of eradication, and stopping immunization.