Funding for this research was provided by:
the National Natural Science Foundation of China (Grant No. 81772154)
The Major Infectious Diseases Such as AIDS and Viral Hepatitis Prevention and Control Technology Major Projects (Grant No. 2018ZX10712001)
Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences (Grant No. 2018RC310027)
Received: 8 April 2019
Accepted: 9 July 2019
First Online: 23 August 2019
Ethics approval and consent to participate
: This study was approved by the Research and Ethics Committee of National Institute for Communicable Disease Control and Prevention. The samples used in this study were throat swab specimen, which was non-invasive. Therefore, informed consent was obtained in an oral confirmation form. No written informed consent was obtained from the parents of each child. These samples were only used in this study with no commercial objectives. The parents of the children involved in the sample collection approved the preparation of the manuscript.
: Not applicable.
: The authors declare that they have no competing interests.