To rapidly and sustainably stop outbreaks of circulating vaccine-derived poliovirus type 2 (cVDPV2) in African countries, a modified vaccine, known as novel oral polio vaccine type 2 (nOPV2) is now being rolled out.
Last year, on 25 August 2020, Africa made history with the African Region Certification Commission for Polio Eradication independently certifying that the Region was free of wild poliovirus. This is the second disease to be kicked out of Africa after smallpox more than 40 years ago.
This achievement is remarkable, considering that in the 1990s wild poliovirus paralysed more than 75,000 African children every single year – a situation that prompted Nelson Mandela in 1996, joined by Rotary International and other partners, to issue a stark call to action: Kick Polio Out of Africa!
All strains of wild poliovirus have now been interrupted in the continent. The last case of wild poliovirus was in August 2016.
However, this tremendous progress remains an unfinished success story. Although Africa is free of wild poliovirus, countries continue to be affected by another form of the virus, known as circulating vaccine-derived poliovirus type 2 (cVDPV2). Such strains are rare, but can occur in under-immunized communities with limited access to safe water and sanitation.
Populations that are adequately immunized are protected from both wild and vaccine-derived strains of poliovirus. However, because of gaps in immunization coverage across Africa, 20 countries have been affected by cVDPV2 outbreaks since 2018.
Now, intensified efforts are being launched to finish polio once and for all, to ensure no child in Africa will ever be paralysed by any strain of this virus.
The novel OPV2 vaccine has been in development since 2011, and in November 2020, WHO’s Prequalification Team issued an emergency use listing (EUL) recommendation enabling initial roll-out in countries affected by cVDPV2 outbreaks. Soon after the issuance of the EUL, the WHO Regional Director for Africa, Dr Matshidiso Moeti, advocated to countries to use this additional tool to stop all forms of polio in Africa.