Health ministers from the six countries said that they would intensify efforts to immunize 250 million children against polio by the end of this year.
Health ministers from the six countries said that they would intensify efforts to immunize 250 million children against polio by the end of this year.
非洲六国加强对儿童大脑灰质炎疫苗接种工作，2。5亿儿童从中得益。