IN a huge and very important milestone for Africa, the World Health Organisation has declared that the entire continent of Africa is free of wild poliovirus.
This comes after four years without a single case. The world is now closer to achieving global polio eradication. If it can be done, it will be the second infectious disease, after smallpox, to be eliminated.
It’s not been easy and has taken millions of health workers travelling by foot, boat, bus and bicycle to reach children in remote areas, over decades. Health workers have even braved conflict to prevent children from enduring life-long disability and paralysis.
The effort has also involved a huge disease surveillance network to check sewage for the virus and test cases of paralysis. Polio still exists along the border between Pakistan and Afghanistan. And until the virus is knocked out of that region, children everywhere are still at risk of contracting the disease.
There is also another danger: the oral polio vaccine most children get contains a weakened poliovirus. In areas where the water is polluted and hygiene is poor, the virus can continue to circulate when it’s excreted. It’s rare, but sometimes the vaccine-derived virus infects children and causes paralysis. Rapid response teams then rush to the area to re-immunise the children and stop the vaccine-derived virus from spreading.
A different oral vaccine, one that’s more stable, will be introduced next year to prevent that from happening.