This process, I said, this ancient process of taking scabs from patients and introducing them to people you wanted to protect, was called variolation.

这个过程,我想,这个从病人身上取痂,接种到你想保护的人身上的古老过程,叫做天花接种

耶鲁公开课 - 生物医学工程探索课程节选