The most striking feature about the impact of Covid-19 on children is how little research has been conducted in the field. Only a handful of studies have been carried out across the world, and scientists are divided over their interpretation. As a result, politicians are now being asked to decide if they should open schools in order to protect children’s mental health and education without any clear scientific guidance about the risks of triggering a second wave of Covid-19 and infecting school staff in the process. It is known that children are less likely to become ill if infected with the coronavirus but researchers are still unsure how easily they can infect others. Some research indicates that children are far less likely to become infected compared with adults but other studies suggest that when they do become infected, they carry as much viral load as an adult, and therefore pose a real risk of passing the virus on to others. The situation was summed up by a senior Labour frontbencher last week: “Either you put the education of children at risk by keeping schools closed, or you take a risk with their safety. There is no easy answer. The problem is that if we say to parents they must send their children back to school, and there is one awful case involving a teacher or a pupil who contracts Covid-19, then it is all over the media.” Last week, Tory MP Robert Halfon, chairman of the select committee on education, backed calls for a phased re-opening of schools. “It is vital children get back into the classroom when it is safe to do so. Otherwise we will face a decade of educational poverty and a safeguarding crisis affecting vulnerable children.” Dr Alasdair Munro, a paediatric infectious disease expert at University Hospital Southampton, also favours an early return to school. To support the idea, he highlighted a key study carried out in the Italian town of Vò, where there was a major Covid-19 outbreak in February. “The authorities tested more than 80% of the population and found 2.8% were positive to the coronavirus. Crucially, not one child under 10 was found to have been infected, and that remained the case when testing was repeated two weeks later. Yet quite a number of children were living in households with infected people.” Other studies in Iceland, Norway and South Korea have also found very low rates of infected children in communities. However, these findings contrast with last week’s Office of National Statistics’ disclosure that in its testing of 10,000 individuals in the UK, it found “no evidence” of differences between age groups in the proportions of those testing positive. “That has thrown a bit of a spanner into the works,” admitted Munro. In addition, there is the question of the amount of virus that a child might carry, which would indicate how easily he or she could go on to infect others. If children have lower viral loads than those typically carried by an adult, children would pose less of a risk in boosting infections rate. However, research carried out by a team led by German coronavirus expert Christian Drosten at the Charité hospital in Berlin found no significant difference between any age categories, including children. “Viral loads in the very young do not differ significantly from those of adults. Based on these results, we have to caution against an unlimited re-opening of schools and kindergartens in the present situation. Children may be as infectious as adults.” By contrast, a study – by Kirsty Short at the University of Queensland – has found that children are rarely the first to bring an infection into a household. In only 8% of cases were children found to be the ones to bring Covid-19 into a home. This figure contrasts with flu, where children are thought to trigger cases in about 50% of outbreaks in households, and this suggests Covid-19 will not be easily transmitted to homes by pupils returning from schools. Munro described this finding as reassuring and said he thought it would be safe to reopen schools slowly and carefully. “I can understand why people are afraid,” he told the Observer. “We still do not know the exact role of children in the transmission of the virus. However, it does seem to be less than adults’ involvement. “Children are the safest group to take out of lockdown because they have the lowest risk of becoming ill from Covid-19 and appear to pose a lower risk of infecting others. And we should also remember that keeping them out of schools is detrimental to their long-term prospects in life.” This view was backed by Professor Saul Faust of University Hospital Southampton. “Slowly opening schools in a controlled way will be of low risk to children’s health and less risk to teachers than the risk to many other workers when on public transport or in other environments.”