The World Health Organization and U.N. children's fund are spearheading a massive immunization campaign across Africa to rid the continent of the last vestiges of polio.
Tens of thousands of health workers will fan out across 13 central and western African countries to vaccinate more than 116 million children under age five against the crippling disease.
The U.N. agencies report more than 190,000 volunteers, traveling on foot or bicycle, will go house to house across all cities, towns, and villages in 13 countries to vaccinate every child under age five against polio.
The synchronized vaccination campaign, one of the largest ever conducted in Africa, will run from March 25-28. Director of Polio Eradication at the World Health Organization Michel Zaffran said children must be immunized in a short span of time to raise childhood immunity to polio across the continent.
"The synchronization of this immunization campaign is needed to rapidly strengthen protection," he said. "If all children are vaccinated at the same time or around the same time in a very short period of time, the virus cannot find anywhere to hide."
In August 2016, four children were paralyzed by polio in Borno State, in northeast Nigeria, which has been under attack by Boko Haram militants for several years. It was the first time in more than two years that polio was detected in Africa.
Governments in the Lake Chad basin declared a public health emergency and a vaccination campaign was conducted. Zaffran said there has been no case of polio since the last one was detected on August 21.
Nevertheless, he told VOA there is concern the polio virus still may be circulating in this area because of the humanitarian crisis, exacerbated by political instability and conflict. He said health workers are operating under very dangerous and difficult circumstances.
"We cannot be sure that some of our vaccinators or health workers cannot be collateral damages of suicide bombing, which is not directly attacking the vaccination site," he said. "This has not been the target of these insurgents, but there could actually be hurt because of the proximity of the events."
The African countries will be declared polio free if no case of polio is detected in the next three years.That will bring the goal of global polio eradication very near as only five cases of polio remain in Afghanistan and Pakistan.