Controlling Cholera May Be Easier Than Thought (2/2)

Ira Longini at the Fred Hutchinson Cancer Research Center in Seattle, Washington, led the new work. A team from the United States, South Korea and target=_blank>Bangladesh based it on a large study of oral cholera vaccine. The study took place between nineteen eighty-four and nineteen eighty-nine. It involved two hundred thousand women and children in rural Bangladesh.

The team developed the computer model based on the results of the study. The model showed that if fifty percent of a high-risk community is vaccinated, many unvaccinated people also would be protected.

The researchers say the number of new infections could drop below one in one thousand people in the unvaccinated population. This would be the result of what is known as "herd protection." The idea is that vaccinated people would not become infected, so they would not create conditions for spreading the disease. Unvaccinated people then would have a better chance of avoiding it.

Ira Longini says researchers are very good at predicting where cholera is likely to spread. So vaccination efforts could target those areas. The findings appear in the medical journal published by the Public Library of Science and available free of charge at plos.org.

参考译文：

华盛顿西雅图弗雷德-哈钦森癌症研究中心 (Fred Hutchinson Cancer Research Center) 的 Ira Longini 带领的由美、韩、孟加拉等国专家组成的国际研究员队伍基于口服霍乱疫苗开展了大量崭新的研究。该研究从1984年开始，1989年结束。总共有大约20万来自孟加拉农村的妇女和儿童参加了此项研究。

小组基于霍乱疫苗试验的数据构建了一个计算机模拟模型，模型显示如果只有50%的高危社区进行疫苗接种，那么未进行预防接种的大量人群得霍乱病的可能性也会大大降低。

研究者称未接种疫苗的人群的感染率会降至千分之一以下。这就是所谓人群保护的结果。这个观点是根据服用过疫苗的人们不会被传染，从而不具备传播疾病的条件，这样，未服用疫苗的人群就有了相应较好的避免感染的环境。

Ira Longini 称专家们善于预测霍乱可能传播的高发区域。所以疫苗接种可以重点安排在这些地区。这些发现发表于公共科学图书馆的医学期刊上，并可以通过网站plos.org免费订阅。