1. Institute of Blood Transfusion; Chinese Academy of Medical Sciences; Chengdu P.R. China
2. Johns Hopkins School of Medicine; Baltimore Maryland
3. Westat, Inc.; Rockville Maryland
4. Guangxi Blood Center; Liuzhou Guangxi P.R. China
5. Kunming Blood Center; Kunming Yunnan P.R. China. Urumqi Blood Center; Urumqi Xinjiang P.R. China. Mianyang Blood Center; Mianyang Sichuan P.R. China. Luoyang Blood Center; Luoyang Henan P.R. China. Johns Hopkins School of Public Health; Baltimore Maryland