Hu, Yu
Wang, Ying
Chen, Yaping
Liang, Hui
Chen, Zhiping
Article History
Received: 16 April 2018
Accepted: 16 November 2018
First Online: 27 November 2018
Authors’ information
: All authors are from the institute of immunization and prevention, Zhejiang Center for Disease Control and Prevention, Hangzhou, China.
: This study was approved by the ethical review board of Zhejiang provincial center for disease control and prevention (T-029-S). All methods were carried out in accordance with relevant guidelines and regulations. Written informed consent was obtained from a parent or a legal caregiver of each eligible child enrolled in this study.
: Not applicable.
: The authors declare no conflicts of interest.
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