A Surge in Hospitalized Young Children Infected With the Coronavirus

C.D.C. researchers are watching for signs that Omicron may affect the youngest children in unforeseen ways, but other factors may explain the rise.

The number of hospitalized young children infected with the coronavirus rose precipitously last week to the highest levels since the beginning of the pandemic, according to data released on Friday by the Centers for Disease Control and Prevention.

The increase was observed in children who were 4 and younger, who are not eligible for vaccination, and the data included children who were admitted to hospitals for reasons other than Covid.

The rise may be partly explained by the surge of Omicron cases, which affects all populations, and the spread of other respiratory infections.