Document is current

Article History

Received: 7 May 2021

Accepted: 30 September 2021

First Online: 14 October 2021

Declarations

:

: All experimental protocols were approved by the Korea Centers for Disease Control and Prevention, and all research methods were carried out in accordance with its guidelines and regulations. <b>W</b>ritten informed consent was obtained from all subjects or<b>,</b> if subjects are under 16, from a parent and/or legal guardian, prior to participation in the survey by the Korea Centers for Disease Control and Prevention<i>.</i>

: Not applicable.

: The authors declare that they have no conflicts of interest.