The review, by the Don’t Forget the Bubbles paediatric research project, added: “Notably, the China/WHO joint commission could not recall episodes during contact tracing where transmission occurred from a child to an adult.”
Among the evidence is a study of a nine-year-old British boy who contracted coronavirus in a French Alps but did not pass it on despite having contact with more than 170 people at three schools.
The boy, among the cases linked to Steve Walsh, the first Briton to test positive, also had influenza and a common cold which he passed to both of his siblings – but neither picked up Covid-19.
Kostas Danis, an epidemiologist at Public Health France who carried out that study, said the fact that children develop a milder form may explain why they do not transmit the virus.
He said that while it was possible children could infect others, there has not been a case to date and there is “no evidence that closing schools is an effective measure”.
Further evidence from China showed that, when families had contracted the virus, children were “unlikely to be the index case”.
Professor Russell Viner, the president of the RCPCH, said: “From around the world, we are not seeing evidence that children are involved in spreading or transmitting the virus, but we do not have enough evidence.”
Prof Viner added that it was too soon to say children could hug their grandparents, particularly as the over-70s are the most vulnerable.