Nigeria reported 1,027 cases of the circulating vaccine-derived poliovirus type 2 in 2021,

This is contained in the 2021 annual report released by the World Health Organisation.

The WHO said 2021 witnessed a resurgence in the incidence of cVDPV2 due to suboptimal population immunity.

The report also showed that 7,770 Acute Flaccid Paralysis cases were reported in 2021 against 6,324 in 2020 and 7,509 in 2019.

The report read in part “Nigeria was certified wild poliovirus-free in August 2020. However, the country saw a resurgence of the incidence of cVDPV2 in 2021 mainly due to suboptimal population immunity.

“Having achieved the required criteria for introducing the novel Oral Polio Vaccine type 2 under Emergency Use Listing, Nigeria became the first country to use nOPV2 in outbreak response in March 2021.

“Nigeria reported 1,027 cVDPV2 cases affecting 31 states and 204 LGAs. The burden was highest in the northern region.

“The response was conducted under challenging circumstances-increasing insecurity, COVID-19, other outbreak response activities, and Global Polio Eradication Initiative ramp-down. In addition, there was a delay in response to the cVDPV2 outbreak due to limited nOPV2 supply, which further increased the risk of spreading the virus. The 36 states and the FCT implemented at least two outbreak responses using nOPV2 in 2021.”

The health body listed the major challenges as limited availability of nOPV2 doses, affecting responding to the cVPDV2 outbreak with the required scope and speed.