Why does OPV cessation need to occur in an internationally-simultaneous way?
A. Due to the proven risk of exportation of a virus from one country to another, the use of OPV following the interruption of wild poliovirus transmission will constitute an international public health risk. In order to avoid some countries becoming more vulnerable to infection by a VDPV than others, it is essential that all countries cease using OPV at the same time.
