来自《耶鲁大学开放课程：1600年后西方社会的流行病 第7集 第7集》

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  and Thomas Jefferson on these shores.
  还有托马斯·杰弗逊
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  Jenner's method, then, was a means to combat
  在那个时候 詹纳的方法是与天花
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  smallpox.
  战斗的利器
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  And unlike inoculation, vaccination didn't introduce an
  与接芽不同 种痘不会使接种人
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  infection of smallpox itself,
  感染天花本身
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  and therefore had no risk of setting off an unintended epidemic.
  因而不会有引发无意的瘟疫流行的风险
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  It also had a low risk of serious complications for the
  种痘也很少在患者个体上引起
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  individual patient,
  严重并发症
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  and no risk at all for the community.
  至于在社群层面上则毫无风险
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  But there were problems with Jenner's method,
  詹纳的方法也有问题
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  and it was to require a series of subsequent improvements to
  这方法还需要进行一系列的后续改进
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  make vaccination a fully successful procedure.
  才能成为完善的疫苗接种方法