ABSTRACT
There is limited information describing the course and severity of illness in subjects infected by the SARS-CoV-2 Omicron variant, especially in children. In this population-based cohort study, subjects with Omicron variant infection during the outbreak between January 8 and February 12, 2022 in Tianjin, China were included. The main outcomes were the distribution of illness severity and clinical courses. Of the 429 subjects (113 [26.3%] children; 239 [55.7%] female; median age, 36 years [IQR 15.0 to 55.0 years]), the proportion (95% CI) of symptomatic subjects on admission was 95.6% (93.2%, 97.2%), including 60.4% (55.7%, 64.9%) mild, 35.0% (30.6%, 39.6%) moderate, and 0.2% (0.0%, 1.3%) severe. Compared with adults, children had lower proportion of moderate Covid-19 (8.8% vs 44.3%). The median (IQR) length of hospital stay was 14.0 (12.0, 15.0) days. Symptomatic and moderate Covid-19 in Omicron infections was common in adults and children.