But what was really needed in order to do this was a defined preparation, right?

为了给每个人带来相同的免疫效果,我们需要精准的疫苗制剂

耶鲁公开课 - 生物医学工程探索课程节选

So, if you were someone that was getting it after it had been passed through many people, you wouldn't have as strong or as lengthy a protection as the first individual did.

如果一个疫苗经过很多人的传递,再接种到你身上,你不会获得像第一个接受疫苗的人,那样强效持久的免疫效果

耶鲁公开课 - 生物医学工程探索课程节选