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

The memory cells, which are stimulated, lead to an IgG response and that's why IgG is the antibody of-- that is produced predominantly after the boost, but there is some IgM produced also.

记忆细胞受到刺激之后,可以诱发分泌IgG的应答反应,这也是为什么IgG,是接种疫苗后产生的主要抗体,与此同时也刺激产生了一些IgM

耶鲁公开课 - 生物医学工程探索课程节选