IfE found that 52 countries that sent students back to school in August and September – including France and Spain – saw infection rates rise during the vacation compared to when they were closed.

In Britain and Hungary, however, infection levels dropped after initial school closures, remained low during the holidays, and began rising after reopening.

Full analysis of these 52 countries found no firm correlation between school status and infections – pointing to a need to consider other factors, IfE said.

“The key now is to learn from those countries that are reopening effectively against a backdrop of rising infections,” Grob-Zakhary said.