In the Sabin vaccine, or the oral polio vaccine, now you have a non-virulent virus.

在沙宾疫苗,即口服小儿麻痹症疫苗中,存在非致病性病毒

耶鲁公开课 - 生物医学工程探索课程节选

A Christian civilization was deeply at the root of this cluster of ideas we call Manifest Destiny, as was a virulent kind of nationalism that boomed after the War of 1812 and through the 1820s into the 1830s.

基督教文明是我们所称的命运天定,及其相关思想的核心,它是一种有害的民族主义,在1812年战争后兴起,并流行于十九世纪二十年代和三十年代

耶鲁公开课 - 美国内战与重建课程节选

So, it's more effective because it's a live virus but it's a little bit more concerning because it's a live virus as well, in that you trust that it's attenuated but could it convert back to a virulent form or a form that caused a disease.

因此,口服疫苗更加有效,因为它是活性病毒,但又是因为这一点,人们也存有更多顾虑,当它处于减毒状态时你会信任它,但是它会不会转变回,强毒壮态或者致病状态呢

耶鲁公开课 - 生物医学工程探索课程节选