Children and adolescents are half as likely to catch the coronavirus, the largest review of the evidence shows.
The findings, by UCL and the London School of Hygiene and Tropical Medicine, will feed into the debate about how schools are reopened.
Children also appear less likely to spread the virus, but the team said there was still uncertainty on this.
The UK government is expected to publish its scientific advice on schools later.
However, only England has announced that some primary children (Reception, Year 1 and Year 6) could return to the classroom, sparking concerns about safety.
It is already clear that children are at far less risk of becoming severely ill or dying from coronavirus.
However, two other key questions have proved harder to answer:
are children less likely to