Hundreds of millions of children around the world have missed out on some schooling over the past year.

In the UK, only vulnerable children and those with key-worker parents have been attending throughout the crisis. Now, ministers are making cautious moves towards welcoming more pupils back to the classroom as Britain’s second wave begins to subside.

So what could reopening mean for children, staff and the epidemic?

‘Extremely low’ risk to children

As FactCheck has reported, one of the few consolations of this crisis has been that children are relatively safe from serious covid disease compared to adults.

We can see this in figures from the Office for National Statistics (ONS), which show eleven deaths involving covid-19 among under-15s in England and Wales between December 2019 and February 2021. These statistics represent tragedies for the families involved, while also revealing that coronavirus fatality in this age group is mercifully rare.

Dr Alasdair Munro, a clinical research fellow in paediatric infectious diseases at the University of Southampton, told FactCheck this week: “The risk to children themselves is extremely low and in keeping with that from other routine respiratory viruses.”

Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, told MPs on Wednesday that among the scientific community, “we’re all quite clear that children themselves, school aged children, are at very low risk from this infection”.

What about school staff?

ONS analysis over the period between 8 March and 28 December last year found “rates of death involving covid-19” among education workers were “not statistically significantly raised when compared with the rates seen in the population among those of the same age and sex”.

A separate December 2020 report by Public Health Scotland said its results “provide reassurance that there is no evidence that teachers have been at increased risk of hospitalisation with COVID-19 in the two periods when in-person teaching has been taking place since the start of the pandemic”.

And Professor Woolhouse told MPs on Wednesday that there’s “good evidence now that teachers and other school staff are not at any elevated risk from covid-19 compared with other working professions”.

Though, as Dr Munro points out to FactCheck, the risk to teachers of catching the infection may increase when they move from virtual to in-person tuition because they’re likely to be in contact with more people. He adds that “individual risks for staff will depend on their age and comorbidities” (underlying health conditions).

We should also remember that the data on school staff won’t fully account for the UK variant first picked up in Kent. The picture may change when more students return to the classroom.

Do schools increase the spread of infections?

Professor Woolhouse says this question has been discussed “at length” on the government’s SPI-M committee of experts and “there is a range of views”. We can see this in the latest scientific literature.

Researchers at the University of Warwick have released a draft paper (not yet peer-reviewed) which concludes “there is not sufficient evidence to suggest that outbreaks in schools are driving an increase in community cases” (i.e. infections in the wider population).

By their model, there is some evidence that the opposite might be true: “that an increase in incidence in the community leads to more cases in school”. They describe a “lag” between cases in the general public which then appear to trickle into schools, rather than the other way around.

On the flipside, modellers at the London School of Hygiene and Tropical Medicine (LSHTM) have published their own draft study which suggests reopening schools could drive the R number above 1, causing the epidemic to grow (rather than shrink, as it is at the moment).

Dr Konstantin Blyuss, reader in mathematics at the University of Sussex, explains the research is “based on the ongoing CoMix survey, in which a representative sample of population are reporting their contacts, which provides insights about interactions between people in different age groups and different settings”.

Though Sarah Lewis, professor of molecular epidemiology at the University of Bristol, notes that “it doesn’t necessary follow that if a child’s contacts change from 5 per week to 30 when they go back to school that there will be 6 times as many infections” because transmission in schools is lower than in other parts of society. The LSTHM authors acknowledge this limitation, and Professor Lewis says “it is likely to have a big impact on their results”.

‘Not a simple answer’

So is it safe – or, at least, safe enough – to open schools?

We put that question to Dr Munro, who told us: “I don’t think we can talk about it being ‘safe’ to open schools exactly, because opening any sector of society will increase transmission to some degree, and even if relatively little transmission happens in schools they are a large sector of society”.

He says “the most important factor by a considerable margin is total rates of community transmission – this combined with the degree of existing restrictions outside of schools plus any increase in mitigations can reduce risks.”

The safest option in his view is to “wait for cases to be extremely low then open up stepwise, starting with youngest children first”. Though as he notes, this has the significant downside of delaying older children’s education and exacerbating mental health concerns.

Professor Woolhouse also expressed caution on Wednesday: “we don’t want to get into a race between the R number greater than 1 and vaccinating”, which would be a “very dangerous balance to try and make”. But he also points out that as more people are vaccinated, “it does weaken the link” between the R number and hospitalisations and deaths.

So even if schools do increase the spread of the disease, this won’t necessarily translate into severe illness and death in the same way once more people have been jabbed.

FactCheck verdict

As ministers across the UK edge closer to the possibility of opening schools to more or most pupils, the latest data shows children themselves remain at very low risk of serious disease and death from coronavirus.

School staff do not appear to be at greater risk from severe illness compared to others in comparable positions. Though we don’t know if the picture will change once we take full account of the new variant first detected in Kent.

The greatest uncertainty remains around the role schools play in spreading the virus among the community. There’s some evidence that they drive transmission, but other data suggests school outbreaks might simply reflect the rates of covid in the wider population.

Policy makers and scientists face a tough set of choices as they weigh the virus against other important factors like kids’ education and mental health – and the strain on parents. As Dr Munro says, there’s “not a simple answer”.