The World Health Organization (WHO) is set to certify that the African continent is free from wild polio, four years after the last cases appeared in northeastern Nigeria.

The WHO said this in a statement in which it thanked the relentless efforts by governments, donors, frontline health workers and communities.

The health body said up to 1.8 million children has been saved from the crippling life-long paralysis.

The official announcement is due in a videoconference with W.H.O Director-General, TEDROS GHEBREYESUS and key figures including philanthropist and Microsoft founder BILL GATES.