1. Wuhan Institute of Biological Products Co. Ltd, Wuhan, China
2. Shanxi Provincial Centers for Disease Control and Prevention, Taiyuan, Shanxi, China
3. Chaoyang Center for Disease Control and Prevention, Taiyuan, Shanxi, China
4. National Engineering Technology Research Center of Combined Vaccines, Wuhan, Hubei, China
5. Qinyuan County Center for Disease Control and Prevention, Taiyuan, Shanxi, China
6. Quwo County Center for Disease Control and Prevention, Taiyuan, Shanxi, China
7. China National Biotec Group Company Limited, Beijing, China