Now, the problem, or one of the challenges with clinical trials of vaccines is that you have to enroll a lot of patients into clinical trials because only a few are going to get sick in any case, only 20 out of 100,000.

现在的问题是,这也是疫苗临床试验的挑战之一,临床试验必须包括足够多的病人,毕竟只有一小部分人会被传染,十万人里面只有二十人被传染

耶鲁公开课 - 生物医学工程探索课程节选

There is a very big-- one of the largest clinical trials that the U.S. Government ever did was called the Women's Health Initiative, and there were several purposes built into this particular study, but what it did was it took post menopausal women and randomly assigned them to different dietary conditions.

有一个很大的,美国政府曾经做过的,一个最大的临床试验,叫做"妇女健康倡导计划",这项研究有几个特殊的目的,研究主要是将更年期的妇女,随机分配至,不同的饮食环境中

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选