Africa declared free from wild polio — but vaccine-derived strains remain

Africa declared free from wild polio — but vaccine-derived strains remain

Africa declared free from wild polio

The World Health Organization has declared Africa free of wild polio. The continent’s last case of wild polio was recorded four years ago in northeast Nigeria. There are now just just two countries on Earth where the virus remains endemic: Afghanistan and Pakistan. Africa’s fight against polio isn’t over: in rare cases, infections can be caused by the oral polio vaccine. These vaccine-derived polio strains can spread in areas where many children have not been immunized, so vaccination must continue.

Nature | 3 min read