[1] Sichuan Univ, West China Teaching Hosp 4, West China Sch Publ Hlth, Chengdu 610064, Peoples R China
[2] Chinese Acad Med Sci, Canc Inst Hosp, Beijing 100730, Peoples R China
[3] Peking Union Med Coll, Beijing 100021, Peoples R China
[4] GlaxoSmithKline Vaccines, Wavre, Belgium