Basically, injecting it into some test subjects, making sure that they didn't get diseased from it and looking at antibody responses to see if it worked and it did.

他们把疫苗接种到测试对象体内,确定接种者不会感染疾病,同时观察抗体的应答反应,了解疫苗是否有效

耶鲁公开课 - 生物医学工程探索课程节选