以拯救生命的五价疫苗所取得的进展为例。 这种疫苗可以保护儿童免患白喉、破伤风、百日咳、乙肝和乙型流感嗜血杆菌（Hib ） — —只需要打一针就可以。
Consider the progress that has been made with the lifesaving pentavalent vaccine, which protects a child against diphtheria, tetanus, whooping cough, hepatitis B, and haemophilus influenza type b (Hib) – all in one dose.