The study could not establish whether younger children were any less likely to be susceptible to the virus than older ones.
Researchers said most children have asymptomatic infection, meaning they were likely to be less infectious than those with symptoms, but they added that it was important to take into account the social behaviour of children, such as how many people they were likely to be in contact with as well as levels of physical interaction.
Researchers concluded that their findings imply children are likely to play a lesser role in transmission of Covid-19 at a population level because fewer are likely to be infected in the first place. However, they did not establish the extent to which children can transmit the virus once infected.
The analysis said there were few studies examining transmission rates of the virus, and said the evidence that existed was weak.
Prof Viner said: “It’s preliminary evidence, but the weight of evidence, I think in summary, is clear that children appear to be less susceptible to SARS-CoV-2.
“We don’t have any data on transmissiblity. We clearly have a state of uncertainty. I believe it is not helpful to make statements about what is safe and not safe as absolutes. All safety is a degree of safety.
“There are safety issues walking out of our front doors, there are safety issues getting in our cars to drive our children to school – we cannot ever say something is safe or unsafe.
“It is well known that children and young people make up only a very small percent of confirmed clinical cases of Covid-19 in most countries, including the UK. Children and teenagers make up an even smaller proportion of severe cases or deaths.
“However, such data about confirmed infection among clinical cases tells us little about susceptibility or transmission as most children have few, if any, symptoms and therefore many do not present for testing or come to the attention of doctors.”
Fellow author Professor Chris Bonell, from the the London School of Hygiene and Tropical Medicine said schools should take steps to try to “break up the chain of transmission”.
These could include an “on/off rota” so pupils attend school on alternate days, and steps to limit contact between parents at school gates.
Researchers said there was limited research examining the likelihood of transimission from children to others, describing the strength of Australian research which found “very limited” spread in schools as “very weak”.