Despite being certified free of wild poliovirus, Nigeria continues to administer polio vaccines to protect children from the threat of Circulating Vaccine-Derived Poliovirus (cVDPV), according to the World Health Organisation (WHO).
WHO Coordinator in Anambra State, Dr. Bonos Mohammed made this clarification at a stakeholders’ forum ahead of the upcoming National Immunisation Plus Days (NIPDs) campaign. The event was organised by the Anambra State Primary Health Care Development Agency (ASPHCDA) in collaboration with the state Ministry of Health and development partners.
Mohammed noted that while Nigeria has eradicated wild poliovirus types 1, 2, and 3, the country remains vulnerable due to international travel and trade, particularly with Pakistan and Afghanistan — the only two countries still reporting wild polio cases.
“Though we’ve had no recent imported cases of wild poliovirus, we are currently dealing with outbreaks of vaccine-derived poliovirus, which occurs in areas with low immunisation coverage,” he said.
He explained that the Oral Polio Vaccine (OPV) contains a weakened virus that can be shed by vaccinated children. In under-immunised communities, this virus can mutate and regain the ability to cause paralysis, resulting in what is known as cVDPV.
“Children with low or no immunity are at risk of infection and paralysis if exposed to this mutated virus,” Mohammed warned.
Although Anambra State has not recorded any cases of cVDPV, Mohammed cautioned that the risk of transmission remains due to population movement from regions still reporting outbreaks, especially in northern Nigeria.
He emphasised that complete vaccination coverage is the only way to stop the spread. “If all children are immunised, the virus has nowhere to go. That’s why we must continue the campaign,” he said.
The Executive Secretary of ASPHCDA, Mrs. Chisom Uchem announced that the next round of the NIPDs will be held from May 3 to May 6, with a mop-up exercise from May 7 to 8, and a final evaluation between May 9 and 11 to assess coverage and effectiveness.
Also speaking, the state health educator, Mrs. Uju Onwuegbuzina urged parents and caregivers to ensure their children are vaccinated during the campaign period.