Incidence Rates and Clinical Outcomes of SARS-CoV-2 Infection With the Omicron and Delta Variants in Children Younger Than 5 Years in the US

Incidence Rates and Clinical Outcomes of SARS-CoV-2 Infection With the Omicron and Delta Variants in Children Younger Than 5 Years in the US With the Omicron variant (B.1.1.529), SARS-CoV-2 infections and hospitalizations reached record levels. 1 Children younger than 5 years may be especially vulnerable because they are not eligible for COVID-19 vaccination. 2 We examined incidence rates and clinical outcomes of Omicron infection before and after Omicron became the predominant variant in the US.