Sean O'Leary said that children have accounted for a greater proportion of overall Covid-19 cases in the United States since vaccines have become widely available for adults. Between Nov. 11 and Nov. 18, pediatric cases made up around a quarter of all Covid-19 cases in the country.
"Is there cause for concern? Absolutely,” O'Leary said. "What's driving the increase in kids is there is an increase in cases overall."