translation.en: So what's concerning us? Well, first of all, at no time in history have we succeeded in making in a timely fashion, a specific vaccine for more than 260 million people.
translation.zh: 那么什么让我们如此焦虑呢？首先， 历史上从来没有人能 为超过2.6亿人成功制备过 适时、特异性的疫苗。