They were so effective and cost effective and yet immunization rates were on the decline if you look back 10 years ago, However,she says in the last nine years, immunization rates for such diseases as diphtheria, tetanus and pertussis have risen sharply.

VOA: standard.2010.01.29

Yeah, so you're asking, if for example, why do you need a booster of tetanus, because if I get exposed to tetanus wouldn't I have this rapid response?

所以你会问,举个例子来说,已经感染过破伤风杆菌的人,为什么仍然需要接种破伤风疫苗,身体不是应该马上对该病菌做出应答吗

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

The answer is "Yes you would", the question is "Would that response, even though it's much faster, be fast enough to protect you from the initial exposure to tetanus that you got?"

是的,你的身体会马上做出应答,问题是 即便免疫应答十分迅速,但是否足够迅速,以保护你不被破伤风杆菌感染

耶鲁公开课 - 生物医学工程探索课程节选