Scientists are investigating whether a mutant new variant of coronavirus is more dangerous for children and young people.
Coronavirus has so far mainly affected the elderly and vulnerable groups, with children very rarely falling seriously ill with Covid-19 and generally showing fewer symptoms.
But concerns are being raised over the behaviour of new variant – named VUI-202012/01 – which appears to be more than 70 per cent more transmissible than its predecessor.
Why have these concerns emerged?
The UK government's New and Emerging Respiratory Virus Threats advisory group (Nervtag) confirmed on Monday it was investigating links.
Prof Neil Ferguson, from Imperial College London, said that findings showed the variant had a statistically significant higher rate of infection among children than other strains.
“There is a hint that it has a higher propensity to infect children ... but we haven’t established any sort of causality on that, but we can see that in the data.”
How are children more likely to be infected?
Prof Wendy Barclay, from Nervtag and Imperial College London, said the virus’s mutation might have made children more susceptible.
It was speculated that the virus rarely affected children because they have fewer doorways (the ACE2 receptor) the virus uses to enter our body's cells.
“If the [new] virus is having an easier time finding an entrance cell then that would put children on a more level playing field,” Prof Barclay said.
Are children more at risk of falling seriously ill?
This does not appear to be the case.
Despite being more infectious, Prof Barclay said there is no evidence yet to suggest the new strain is making people more ill compared with other variants, but findings showed they have higher viral loads.
Prof Barclay said: "People infected with this variant tend to have higher levels of virus in their swabs."
Prof John Edmunds, from Sage, told BBC Radio 4 there was no evidence that the virus was more likely to harm children. "All of us can be affected by this new strain."
What does this mean for schools?
UK Prime Minister Boris Johnson on Sunday hinted that schools could stage a staggered return to lessons in January to contain the latest outbreak.
Mr Johnson said the government wants secondary school pupils to return to face-to-face lessons in a staggered way in the new year if they "possibly can".
“But obviously ... the commonsensical thing to do is to follow the path of the epidemic and, as we showed last Saturday, to keep things under constant review,” he said.
“It is very, very important to get kids and keep kids in education if you possibly can.”
What are the scientists doing now?
Scientists will be growing the new strain in the laboratory to see how it responds.
This includes looking at whether it produces the same antibody response, how it reacts to the vaccine, and modelling the new strain.
It could take up to two weeks to complete this process.