A vision of a world without polio: the OPV cessation strategy.

Once the eradication of wild poliovirus has been confirmed, the public health benefits of routine immunization with OPV will no longer outweigh the burden of disease either due to paralysis caused by OPV (vaccine associated paralytic polio), or by outbreaks caused by circulating vaccine-derived polioviruses. The eventual cessation of OPV use in routine immunization programmes worldwide will become necessary to assure a lasting eradication of polio. As the world moves towards polio eradication and its certification, preparations are therefore being intensified for OPV cessation, and the risk management framework for safe OPV cessation is being put in place. The framework includes bio-containment of all known poliovirus and potentially infected substances, development of an international stockpile of oral polio vaccine, ensuring a mechanism for continued global surveillance and response for polio after eradication has been certified, and national policies if countries decide to continue vaccinating with inactivated polio vaccine (IPV). It is ironic that the vaccine on which the world has depended for polio eradication will itself become a risk to eradication once the transmission of wild poliovirus has been interrupted. Final preparations for the eventual global and simultaneous cessation of OPV will require the same level of international cooperation and coordination that has brought the world to the verge of polio eradication.