Study design and participants
DISEASE
This study was a single-center, randomized, double-blind, phase IV clinical trial, which was conducted in Yanliang District, Xian City, Shaanxi Province, China, from July 27This trial was approved by the ethics committee of Shaanxi Provincial Centre for Disease Control and Prevention. Written informed consents were obtained before screening. For participants aged 8 years or older, both their legal guardians and participants were required to sign the informed consent forms, while only their legal guardians signed for participants below eight years. This trial was registered in the ClinicalTrials.gov database with an identifier of NCT05112913. This trial was conducted in accordance with the principles of the International Council for Harmonization Good Clinical Practice, the Declaration of Helsinki and Chinese regulatory requirements.