Health experts, however, said the cases of cVDPV2 do not threaten the country's Wild Poliovirus-free certification.
The Nigerian government has said cases of circulating Vaccine Derived Polio Virus type 2 (cVDPV2) declined in the country between 2021 and 2022.
The Chairman of the Expert Review Committee (ERC) on Polio and Routine Immunisation, Akin Osibogun, while speaking at its 39th meeting on Tuesday, said the country witnessed an 85 per cent decline in cVDPV2 in the space of a year.
Mr Osibogun said with support from government and partners at all levels, the country has been making progress in the fight against polio.
"There has been an 85 per cent drop in the incidence of cVDPV2. We are getting close to achieving the goal of eradicating cVDPV2 in Nigeria," he said.
He noted that "there is a need to focus on strategies, including strengthening routine immunisation and primary health care system and improving our surveillance capability."
Polio Virus
Poliomyelitis (polio) is a highly infectious viral disease, which mainly affects young children. It is transmitted by person-to-person spread mainly through the faecal-oral route or through contaminated water or food and multiplies in the intestine, from where it can invade the nervous system and can cause paralysis.
It would be recalled that Nigeria and the African region were certified Wild Polio Virus (WPV) free in 2020, following a verification and certification process by the African Regional Commission for the Certification of Poliomyelitis Eradication (ARCC) which spanned three years of no detection of WPV.
However, the cVDPV is another form of polio that can spread within communities. While cVDPVs are rare, they have been increasing in recent years due to low immunisation rates within communities especially cVDPV type 2.
According to the World Health Organisation (WHO), Nigeria reported 1,027 cases of cVDPV2 in 2021 due to suboptimal population immunity.
Health experts, however, said the cases of cVDPV2 do not threaten the country's Wild Poliovirus-free certification.
Eradicating polio
Speaking at the event, the Executive Director of the National Primary Health Care Development Agency (NPHCDA), Faisal Shuaib, said the recommendations of the Committee over the years have shaped the ongoing work around vaccination in the country.
Mr Shuaib said the aim is to eradicate every single form of polio, whether it is circulating variants or wild polio virus.
"Today, we want to finalise and fine-tune those plans to make sure that by end of 2023, we would have completely eradicated every form of polio," he said.
"We are not completely free of polio until every single type of polio is eradicated from Nigeria."
Mr Shuaib said various states are also working very hard to ensure the eradication of every form of polio.
In his remark, WHO Country Representative, Walter Mulombo, said the global risk of WPV and cVDPV2 transmission remain high given the endemicity of WPV1 in Pakistan and Afghanistan, and the residual risks in Mozambique and Malawi.
He said there are also concerns about the recent increases in cVDPV2 cases in the Democratic Republic of Congo.
He said given the impact of the COVID-19 pandemic on the economy, the interruption of the cVDPV2 outbreak demands renewed commitments and focus by all key players.
"Reaching and sustaining zero cases of cVDV2 in Nigeria in 2023 is achievable," he said.
He, however, said it would demand more efforts on the country's path in addressing the residual risk of re-upsurge of cVDPV2 in consequential geographies.
Cristian Munduate, UNICEF Country Representative for Nigeria, said UNICEF remains a steadfast partner of the country.
Ms Munduate said the agency would continue to lead efforts in vaccine procurement, logistics, social mobilisation, and community engagement to support the nation's immunisation supply chain for improved vaccine availability and accountability for every child.