The World Health Organization warned on Thursday that an increasing body of evidence suggests children do play a role in the spread of Covid-19, but classrooms are not thought to be a "main contributor" to the pandemic.
It comes as students prepare to return to school both in person and online after the summer holidays, with authorities across the U.S, Europe and elsewhere trying to orchestrate a delicate balancing act.
Many are asking whether restarting the new academic year with robust mitigation measures may be worth the risk to students, teachers and families, given that keeping schools closed could exacerbate learning gaps exposed by lockdown measures.
During a press briefing on Thursday, Hans Kluge, regional director for Europe at the WHO said that, so far, school settings had not been a "main contributor" to the pandemic.
"There's also more and more publications that adds to the body of evidence that children do play a role in the transmission but that this is, so far, more linked with social gatherings," Kluge said.
"So, this is one of the unknowns but definitely top priorities for the policymakers at the World Health Organization."
To date, more than 24.2 million people have contracted the coronavirus worldwide, with 826,368 related deaths, according to data compiled by Johns Hopkins University.
"It is a tricky moment now, when we transition from the summer to the autumn with three phenomena coming together," Kluge said, reflecting on the challenges European countries face over the coming weeks.
He listed the reopening of schools, the upcoming influenza season, and the excess mortality rate in elderly people seen during the winter.
"So, vigilance is really the key word," he said.