Document is current

Article History

Received: 26 November 2025

Accepted: 27 January 2026

First Online: 16 February 2026

Declarations

:

: This study, which utilized anonymized surveillance data from the PTB database, was reviewed and approved by the Ethics Committee of the Zigong Municipal Center for Disease Control and Prevention. As the research involved the analysis of pre-existing, de-identified data, the requirement for obtaining informed consent was waived by the ethics committee. All procedures and methods were carried out in accordance with the ethical standards of the Declaration of Helsinki and the relevant provisions of the “People’s Republic of China Law on the Prevention and Treatment of Infectious Diseases.”

: Not applicable.

: The authors declare no competing interests.