So, you couldn't introduce the live virus in because that would cause the disease not just immunity.

所以 不可以直接接种活体病毒,因为这会使人致病而不仅是引起免疫应答

耶鲁公开课 - 生物医学工程探索课程节选

Who's to say they couldn't eat of that and just live forever?

有谁说过不要吃生命树，吃了便能长生不老？

耶鲁公开课 - 旧约导论课程节选