There is no evidence schools play a significant role in the transmission of the coronavirus in communities, research suggests.
Statistics have repeatedly flagged that children rarely become seriously ill with the infection, with many youngsters experiencing no symptoms at all.
Nevertheless, the extent to which children pass the virus to others, whether it be school staff or elderly grandparents, has been debated throughout the pandemic.
Erring on the side of caution, at-home learning is enforced for most students throughout the UK, despite criticism of the "lockdown generation" missing out on vital socialising and an in-person education.
After analysing coronavirus-related school absences in England between September and December 2020, scientists from the University of Warwick have said there is no substantial evidence that having children in classrooms drives significant community transmission.
They stressed, however, this is an "absence of evidence rather than the evidence of absence".
The youngest primary school pupils in Scotland and Wales are due to return to the classroom on 22 February, the same day Boris Johnson is expected to set out a roadmap for England's lockdown exit.
Downing Street sources have told the BBC they are "increasingly confident" students in England will return to school on 8 March, the earliest date the prime minister has said this could occur.
The Warwick research is yet to be published in a peer-reviewed journal.
"Our analysis of recorded school absences as a result of infection with COVID-19 suggest the risk is much lower in primary than secondary schools and we do not find evidence to suggest school attendance is a significant driver of outbreaks in the community," said study author Dr Mike Tildesley.
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This comes after Northern Ireland's public health agency announced that schools, including "special" ones, are not a major source of coronavirus transmission.
The infection does spread within school grounds, "but tends to be small scale", it added.
The Northern Ireland executive is yet to decide if some or all pupils can return to school on 8 March.
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The coronavirus was identified in China at the end of 2019. By March, the outbreak had evolved into a pandemic, prompting schools to be shut across the UK, except for vulnerable pupils and the children of key workers.
A decline in cases come May led to a staggered return to classrooms in June for reception-aged children, and those in years one and six.
From 15 June, secondary schools began to reopen for years 10 and 12, with all other students continuing to work from home for the rest of the academic year.
All pupils went back to school in England from 1 September, with restrictions including classroom bubbles, staggered drop-off times and mandatory mask-wearing for parents in the playground.
To better understand the impact of this on community transmission, the Warwick scientists analysed absence information from England's educational settings database, compiled by the Department for Education.
The data ran from September to December, when all children were in school.
The information is based only on children who tested positive for the coronavirus. Due to many not developing symptoms and therefore never getting swabbed, the data are expected to be an "underestimate".
The results suggest infections among teachers declined during England's four-week lockdown in November, despite schools being open throughout.
The drop was particularly pronounced in Tier 3 regions, which had the strictest restrictions at the time. The tier system was introduced in October 2020 as coronavirus cases began to rise.
Among secondary school students, coronavirus cases increased in many regions in the first two weeks of the November lockdown, before decreasing.
The introduction of the tier system was linked to fewer coronavirus cases in primary schools compared to secondary schools across all regions.
"During the first two weeks of the November lockdown we observed an increase in pupil absence as a result of infection with COVID-19, yet in the following weeks the data indicates in several regions there was no subsequent rise in COVID-19 caused teacher absence," said co-author Dr Edward Hill.
"It is important to note our findings only refer to cases reported in school children and teachers, and do not provide an indication as to whether these individuals were infected within the school environment."
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In December, once the November lockdown had lifted, secondary school coronavirus absences had markedly increased in the South East and Greater London.
The same was not true for other regions or among primary school students.
The increased transmissibility of the then-new "Kent" variant in the South East and Greater London may have contributed to the rise in cases in secondary schools, according to the scientists.
Overall, they observed a "positive correlation" between incidences in the community and school cases in some regions; however, there was also "some weak evidence" that infections in schools actually lag behind community cases.
"We're not saying there is no risk of children becoming infected in the school environment, but we're not seeing overwhelming evidence children are driving transmission," said Dr Tildesley.
The scientists added: "It is clear the longer children remain out of school, the greater the risk of many children suffering long term from a lack of access to face-to-face teaching and socialisation, with a resulting negative impact upon their mental health and education.
"It is vital processes are put in place to ensure children get back to school as rapidly, but as safely, as possible.
"Our work suggests this can be achieved by ensuring that community incidence is as low as possible when schools re-open.
"However, further measures, such as ensuring parents do not mix at pick-up and drop-off and a reinforcement of the need for people to work from home if they can, may be needed in order for children to return to school safely in the near future."
When asked about schools reopening, Dr Tildesley said there is an "argument for slightly staggering it", but said this was a "political decision".
"They have to weigh up the impact of keeping some children home for longer," he added.