I didn't have the commercial price for the chickenpox vaccine called Varivax but you can imagine that it's even more than $50 a dose for that one.

我不知道水痘疫苗,伏痘敏的商业价格,但是你可以想象一下,这种疫苗每支的价格要超过五十美元

耶鲁公开课 - 生物医学工程探索课程节选

But variola, which causes smallpox in humans, and vaccinia, which causes a disease called cowpox in cattle, turned out to be, we now know, viruses that are molecularly very similar.

但是导致天花的人痘病毒,和导致牛痘,的牛痘病毒,后来发现其实是,我们现在知道,这两种病毒在分子水平上十分相似

耶鲁公开课 - 生物医学工程探索课程节选