A vaccine is a prepared, it's a preparation, that's prepared in some way.

疫苗是一种筹备,是一种准备,它通过某种方式预防疾病

耶鲁公开课 - 生物医学工程探索课程节选

What you would like to is everybody in the community exactly the same preparation so that you could predict what everybody's response to the vaccine would be.

最好是把完全一致的制剂,分发给每个人,这样才能预测每个人,对疫苗的反应

耶鲁公开课 - 生物医学工程探索课程节选