Yi-Xing Li¹, Ming-Hua Li¹, Shi-Hong Fu, Wei-Xin Chen, Qi-Yong Liu, Hai-Lin Zhang, Wa Da, Song-Lin Hu, Sang Dan La Mu, Ju Bai, Zun-Dong Yin, Hong-Yue Jiang, Yu-Hong Guo, Dun Zhu Duo Ji, Hui-Mei Xu, Ge Li, Gu Gu Cuo Mu, Hui-Ming Luo, Jing-Lin Wang, Jun Wang, Xiu-Min Ye, Zhuo Ma Yang Jin, Wei Zhang, Gui-Jun Ning, Huan-Yu Wang, Gui-Chang Li, Jian Yong, Xiao-Feng Liang, and Guo-Dong Liang 

Author affiliations: Author affiliations: National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China (Y.-X. Li, Z.-D. Yin, H.-M. Luo, G.-J. Ning, X.-F. Liang); Institute for Viral Disease Control and Prevention, Beijing (M.-H. Li, S.-H. Fu, W.-X. Chen, H.-Y. Jiang, J.-L. Wang, H.-Y. Wang, G.-D. Liang); National Institute for Communicable Disease Control and Prevention, Beijing (Q.-Y. Liu, Y.-H. Guo, J. Wang, G.-C. Li); Yunnan Institute of Endemic Disease Control and Prevention, Yunnan, People’s Republic of China (H.-L. Zhang); Tibet Center for Disease Control and Prevention, Tibet, People’s Republic of China (W. Da, D.Z.D. Ji, X.-M. Ye); Nyingchi Center for Disease Control and Prevention, Tibet (S.-L. Hu, H.-M. Xu, Z.M.Y. Jin); Medog County Center for Disease Control and Prevention, Tibet, (S.D.L. Mu, G. Li, W. Zhang, J. Yong); Mainling County Center for Disease Control and Prevention, Tibet (J. Bai, G.G.C. Mu)