Viruses, you know about viruses; variola, we're going to talk about next week which causes smallpox, influenza, which causes the flu and HIV of course which cause AIDS are some examples.

病毒 你们都知道病毒,像天花病毒,我们下周会讲的引起天花的病毒,还有引起流感的流感病毒,引起艾滋病的人类免疫缺陷病毒等等

耶鲁公开课 - 生物医学工程探索课程节选

Then, also emphasizing in the case of smallpox, how even after the scientific discovery was made, it took many, many decades for people to be able to produce the vaccine in large enough quantities and distribute it, so that you could think about making an impact on global prevalence of the disease.

同时重点就天花疫苗的发展展开了讨论,而即便当科学发现了天花病毒,仍然过了许多年,人类才能够,大规模生产并使用天花疫苗,由此你们可以了解到,在全球范围内,疫苗给天花以致命一击

耶鲁公开课 - 生物医学工程探索课程节选