Why is it difficult in some cases to produce a vaccine when we've been successful in so many others?

为什么某些疾病的疫苗很难研制,即使我们已经成功生产了很多种疫苗

耶鲁公开课 - 生物医学工程探索课程节选

Now the question is "how does it expand" and "why is it so difficult for us to understand, accept, assimilate and live according to the fact that we can make a difference, if we understand that what we need to understand is how change happens.

问题是“它如何扩大“,以及为什么我们难以理解，我们能够做出改变这个事实,并接受，被同化以及据此生活，如果我们能了解我们需要理解的,是改变如何发生。

哈佛公开课 - 幸福课课程节选