translation.en: It deteriorates so quickly in the tropics that we've had to put this special vaccine monitor on every single vial so that it will change very quickly when it's exposed to too much heat, and we can tell that it's not a good vaccine to use on a child -- it's not potent; it's not going to protect them.
translation.zh: 在赤道地区，它很快变质 我们必须将特殊的疫苗检测器 安在每支疫苗上 因此它能迅速做出反应 当疫苗因为受热过多而改变性质时 我们便知道它不再适用于儿童 因为效力不够，无法保护儿童