The World Health Organization says it will begin a large-scale polio immunization campaign next week in 10 African countries, as an outbreak from Nigeria spreads across the region.
The WHO says tens of thousands of volunteers will go house to house starting on Monday, with the goal of vaccinating 63 million children.
It says polio is again spreading across west and central Africa, paralyzing children in seven countries that had been free of the virus.
The WHO has linked the outbreak to several northern Nigeria states, where Islamic leaders have refused to immunize children over fears the vaccine is contaminated with substances that can cause AIDS, cancer, and sterility.
The WHO says the vaccine is completely safe.
The agency's regional director for Africa, Dr. Ebrahim Samba, says the African continent is on the brink of reinfection unless immunization campaigns stop the polio virus from spreading.
The immunization project will take place in Nigeria, Niger, Benin, Burkina Faso, Cameroon, the Central African Republic, Chad, Ghana, Ivory Coast, and Togo.
Polio usually infects children through contaminated drinking water. It attacks the central nervous system, causing paralysis, deformity and, in some cases, death.