And there is a wildlife agent telling us 'go pick up your traps, I don't care what they have on them.

VOA: standard.2010.05.06

Usually it's done by taking all or part of the infectious agent, and showing them to your immune system in some way.

通常它会带着全部或部分抗原介质,并以某种方式呈递给你的免疫系统

耶鲁公开课 - 生物医学工程探索课程节选