You would have this initial response, now that initial response might be too slow to prevent you from getting chickenpox.

你对水痘病毒产生初始应答,这种初始应答可能,过于缓慢,无法预防水痘

耶鲁公开课 - 生物医学工程探索课程节选

Yeah, so for example, you get exposed to-- before there was a vaccine your brother or sister had chickenpox, and so you got exposed to chickenpox naturally through your contact with them.

举个例子来说,如果你生活在这样的环境里,兄弟姐妹们还没接种疫苗就得了水痘,而你通过与他们相接触,在自然情况下接触到了水痘病毒

耶鲁公开课 - 生物医学工程探索课程节选