Those levels would reach a plateau after some period of time, maybe after a couple of weeks and then they would begin to decline again.

在一段时间后,抗体浓度将达到峰值,峰值大约出现在几周之后,之后,抗体浓度将开始下降

耶鲁公开课 - 生物医学工程探索课程节选

If this was tetanus, you got this tetanus vaccine when you were young; you get a boost every five or ten years because your antibody levels are starting to fall.

以破伤风为例,小时候,你接种过破伤风的疫苗,每隔五年或十年要再接种一次,这是因为体内的抗体浓度会下降

耶鲁公开课 - 生物医学工程探索课程节选

Now, if I was a person that was designing a vaccine and I noticed that this was the response that it got, that antibodies were produced, they reached some intermediate level, they started to fall, I would say, "Well I haven't stimulated the immune system enough, let me re-boost, let me give another dose of antigen."

现在,如果我正在研究一种疫苗,我注意到机体会对这种疫苗产生应答,也就是会产生抗体,当抗体浓度达到中等水平后,就开始下降,就可以说,疫苗对免疫系统刺激还不足,我需要提高抗原浓度,让我再把剂量再加大一倍

耶鲁公开课 - 生物医学工程探索课程节选