Update on Vaccine-Derived Poliovirus Outbreaks - Worldwide, July 2019-February 2020

What is already known about this topic? Circulating vaccine-derived polioviruses (cVDPVs) can emerge in settings with low poliovirus immunity and can cause paralysis. What is added by this report? Thirty-one ongoing and new cVDPV type 2 (cVDPV2) outbreaks were documented during July 2019-February 2020; nine outbreaks spread internationally. New cVDPV2 outbreaks were often linked to poor coverage with monovalent Sabin oral poliovirus vaccine (OPV) type 2 during outbreak response campaigns. What are the implications for public health practice? The Global Polio Eradication Initiative plans to introduce a genetically stabilized, novel OPV type 2 for outbreak response in mid-2020 and expand use in 2021. Cessation of all OPV use after certification of polio eradication will eliminate the risk of VDPV emergence.