Xu, Yingkai, Zihan Yuan, Junying Li, Wanbing Liu, and Lei Liu. 2025. “A Survey on the Situation and Risk Factors of Secondary Infection After the Second Wave of the Omicron COVID-19 in China”. The Journal of Infection in Developing Countries 19 (06):812-20. https://doi.org/10.3855/jidc.20927.