“…Successfully stopping cVDPV2 transmission requires the use of serotype 2 monovalent OPV (mOPV2) in high‐quality immunization activities that achieve high coverage and rapidly raise population immunity to transmission to high levels, and then again stopping its use (Duintjer Tebbens, Pallansch, Wassilak, Cochi, & Thompson, 2016). Nigeria conducted 33 subnational SIAs in various states using mOPV2 with variable quality and scope between mid 2016 and September 2019, which did not stop transmission of cVDPV2 or onward geographic spread (i.e., the cVDPV2 outbreak originating in Jigawa and its spread across Nigeria and subsequently Central and West Africa (Adamu et al., 2019)). The transmission of OPV2‐related viruses thus continued in a population with increasing vulnerability to sustaining serotype 2 live poliovirus transmission (Duintjer Tebbens, Hampton, & Thompson, 2016).…”