We talked about attenuating in the laboratory, using cell culture techniques and what we know about mutating viruses.

我们讲过实验室中,利用细胞培养技术培养减毒疫苗,以及我们所了解的减毒病毒

耶鲁公开课 - 生物医学工程探索课程节选

And so this is an example of a naturally occurring, attenuated vaccine.

这就是一个天然减毒疫苗的例子

耶鲁公开课 - 生物医学工程探索课程节选

He produced an oral polio vaccine from an attenuated virus.

他利用减毒病毒制得口服小儿麻痹症疫苗

耶鲁公开课 - 生物医学工程探索课程节选

This was not a naturally occurring attenuated virus as used in smallpox, but a virus that was attenuated in the laboratory, basically by propagating it in culture and looking for mutants that were formed as you propagated this virus under different experimental conditions.

这不是在制造天花疫苗时,使用的那种天然减毒病毒,而是一种在实验室中被人工弱化的病毒,基本上是通过在细胞中培养繁殖后,从这些培养出来的病毒中挑选出,不同实验环境下的变异体

耶鲁公开课 - 生物医学工程探索课程节选