World faces polio dilemma

日期:2019-03-02 01:16:05 作者:尉迟珂椁 阅读:

By Debora Mackenzie When it comes to eradicating polio, the world is facing a dilemma. Developing countries can no longer be sure that using relatively cheap live polio vaccines will extinguish the virus, yet the replacement killed polio vaccines used in richer developed countries remain too expensive. However, two countries, Indonesia and Mexico are striking out with a new strategy. The dilemma has been brought into focus by news that a strain of polio the world has already eradicated has re-emerged in northern Nigeria. In 2003,