We'll think about it in section, how you don't need to vaccinate everybody, but you just need to vaccinate a critical number in order to stop the disease from progressing through a community.

我们在讨论会上讲这个,为什么不需要给每个人都接种,但你只需要让接种人数达到一个临界值,就能阻止这个疾病在社会中传播

耶鲁公开课 - 生物医学工程探索课程节选

As we'll see in section today, a vaccine does not have to be totally perfect in order to prevent transmission of a disease, because when a disease enters a community its spread from one person to another.

有如我们今天看到的,疫苗不一定非要,绝对完美地阻止疾病的传播,因为当疾病侵入一个社区后,会在人群间传播

耶鲁公开课 - 生物医学工程探索课程节选