Impact of Omicron infection on childhood health: the Beijing long-COVID study - Zhou, Bo; Xu, Qi; Li, Shaoli; Wang, Jianhong; Liu, Junting; Zhang, Ting; Qu, Xia; Wang, Xi; Zhang, Lili; Liu, Xiaoli; Gu, Jialu; Zhou, Lijun; et al. (Frontiers in Public Health, 2025)