Hospitalizations and Clinical Severity of COVID-19 Among Infants Under 1-Year-old.

This study evaluated COVID-19 hospitalizations and clinical severity in infants (<1-year-old, n = 2,667), March 2020-March 2021. Hospitalizations were associated with younger age [OR (95%CI): <1 month, 26.3 (16.1-43.1), 1-2 months, 4.7 (3.1-7.34), 3-11 months, 1.0 (referece, 1.0-1.0)] and symptomatic disease, mainly with fever. Moderate-severe COVID-19 disease was associated with infants age above 3 months [OR (95% CI): 4.0 (1.4-11.1)], ethnicity and underlying conditions.