As fall approaches in the U.S. and school districts debate whether to resume in-person classes, the issue is complicated by a dearth of knowledge about how COVID-19 is transmitted to and from children.
Other nations have sent children back to school -- or never shuttered schools to begin with -- but none has done so with the virus surging as it is in the U.S. On Monday, cases in the U.S. rose by 64,605 from a day earlier to 3.34 million.
It is now broadly recognized that the virus that causes COVID-19 can be airborne in crowded, indoor spaces like schools. And children are commonly known to be spreaders of other respiratory viruses, like the seasonal flu. But while there's significant data showing children aren't likely to become very ill from COVID-19, there's less information on how likely they are to transmit it to others.
"All of the data from every country suggests kids have a low probability of getting sick and dying," said Derek Cummings, who studies transmission of infectious diseases at University of Florida's Emerging Pathogens Institute. "What we don't know is how often they transmit the virus."
The lack of specific data has made some states cautious about how best to move forward at a time when enormous pressure is building to reopen schools from parents who need to return to work, U.S. President Donald Trump, who sees it as a linchpin for the economy, and childhood development specialists concerned about the toll of the pandemic on children's mental health.
On Monday, New York Gov. Andrew Cuomo laid out criteria for the state's schools reopening, saying they'll be allowed to reopen this fall in regions that are in Phase 4 of reopening and have an infection rate of 5% or less on a rolling 14-day average. If the rate rises above 9%, he said, the schools will be re-closed. New York City is currently the only region not in Phase 4.
Trump "was wrong on the economic reopening and he's wrong on the schools reopening," Cuomo said in a briefing. "We're not going to use our children as guinea pigs."
In California, where cases of COVID-19 nearly doubled in the past two weeks, the state's two largest school districts, Los Angeles Unified and San Diego Unified, issued a joint statement on Monday saying they wouldn't resume in-person classes.
Even as cases have risen in the U.S., confirmed infections among those under 18 remain low. Through May, those infections accounted for less than 2% of cases, according to the Centers for Disease Control and Prevention, numbers that have been similarly low around the globe.
While children are at a lower risk of getting very ill, a small number have died or required intensive care as a result of either the respiratory failure commonly associated with the virus or a frightening inflammatory condition sometimes described as similar to Kawasaki disease that causes heart or circulatory problems.