Thanks to an effective vaccine, the polio virus has disappeared from most of the world. But, a few cases remain in areas that are among the most difficult to reach.
得益于一种有效的疫苗，脊髓灰质炎病毒已经在全球大部分地区消失。但是，一些最难以抵达的地区仍然存在少量病例。
To eradicate the virus completely, medical teams are trying to vaccinate children in three countries. The wild polio virus still exists in Afghanistan, Pakistan and Nigeria. But unrest, conflict and the extreme remoteness of these areas has kept thousands of children from receiving polio vaccines this year.
为了彻底根除这种病毒，医疗团队正试图为三个国家的儿童接种疫苗。这种自然生长的病毒仍然存在于阿富汗、巴基斯坦和尼日利亚。但是，这些地区的动乱、冲突以及极度偏远导致今年有成千上万名儿童无法接种脊髓灰质炎疫苗。
Andrew Etsano works as an immunization expert for the Red Cross. He says that one of the difficulties the group faces is how often people in these areas move. They often flee economic problems, political situations or violence.
安德鲁·埃萨诺是红十字会的一名免疫专家。他说，该组织面临的困难之一是这些地区人们的迁徙频率。他们经常因为经济问题、政治局势或暴力而逃离。
Etsano says that, as a result, people take the virus from one place to another. And medical teams cannot always track the migrants in order to vaccinate the children.
埃萨诺表示，因此，人们将这种病毒从一个地方带到另一个地方。医疗团队无法随时跟踪这些流动人口以便为孩子们接种疫苗。
Dr. John Vertefeuille is with the U.S. government's health protection agency, the Centers for Disease Control and Prevention (CDC). He says the CDC uses technology to track migrant groups.
约翰·维特弗伊（John Vertefeuille）就职于美国政府旗下的健康保护机构，即美国疾病控制和预防中心（简称CDC）。他说，美国疾病控制和预防中心利用科技来追踪流动人群。
Researchers look at images from satellites for clues. Structures that have been repaired and roads without grass growing on them may show researchers that people are living nearby.
研究人员从卫星图像中寻找线索。被修复的建筑和没有杂草丛生的道路可能会向研究人员表明，这附近有人居住。
Local is better
最好是本地团队
But when it comes to actually vaccinating people, experts note that local teams are best. Such teams are likely to be aware of an area's culture and customs.
但是，当涉及到给人们实际接种疫苗时，专家提出最好是当地团队。这类团队可能会了解该地区的文化和习俗。
For example, in many places women vaccinate people because they can go into homes, talk to other women and gain access to the children.
例如，在很多地区是由妇女为人们接种疫苗。因为她们可以进到家里，与其他妇女交谈并接触到孩子。
In other places, soldiers vaccinate children when they take over an area run by anti-government forces. But these vaccination teams have to move quickly during short breaks in the fighting. They also have to deliver several doses of the vaccine in a short period of time.
在另一些地区，当士兵们接管反政府武装控制地区时，他们会给孩子们接种疫苗。但是这些疫苗接种小组必须在战斗短暂停止期间迅速行动。他们还得在短时间内提供几剂疫苗。
Even when teams are not providing vaccinations, community volunteers can warn health officials of a polio outbreak. Some volunteers have mobile phones to report if any child becomes unable to use their arms or legs.
即使团队没有提供疫苗接种，社区志愿者也可以提醒卫生官员注意脊髓灰质炎疫情。如果有任何孩子手脚动不了，一些志愿者可以用手机上报。
The goal is to vaccinate everyone before the virus has a chance to change, making the existing vaccines less effective.
其目标是在该病毒有机会变异，导致现有疫苗效果降低之前给每个人接种疫苗。
How long do we have to do this?
我们还要坚持多久？
Efforts to end polio completely have been largely effective.
完全消灭脊髓灰质炎的努力大体上是有效的。
Since 1988, when the Global Polio Eradication Program began, the number of polio cases has dropped by 99.9 percent. In 2017, only 22 people were reported to be crippled by the disease, says the World Health Organization.
自1988年全球根除脊髓灰质炎计划开始以来，脊髓灰质炎病例数下降了99.9%。据世界卫生组织称，2017年据报告只有22人因为这种疾病瘫痪。
But the program's success has introduced new problems. Financial supporters, leaders, health workers and the public are tired of dealing with the problem, especially those who have never seen polio.
但是该计划的成功也产生了新的问题。经济资助者、领导人、卫生工作者以及公众都对处理这个问题产生了厌倦，尤其是从未见过脊髓灰质炎的那些人。
John Vertefeuille said, "The last mile is a complicated mile."
维特弗伊表示：”行百里者半九十。“
But, he and other experts warn, if polio continues to exist anywhere, it could once again spread.
但是，他和其它专家警告说，如果脊髓灰质炎在任何地区存在，它就可能会再次传播。
I'm Jonathan Evans.
我是乔纳森·埃文斯。(51VOA.COM原创翻译，禁止转载，违者必究！)
