Children may be half as likely to catch the coronavirus, research suggests.
Since the outbreak emerged at the end of 2019, experts have wondered how susceptible youngsters are to the infection and how readily they may pass it on.
While the vast majority of deaths worldwide have occurred in the elderly, NHS doctors have been warned to look out for signs of “multi system inflammation” after a handful of children ended up in hospital with life-threatening symptoms.
Medics have likened this to Kawasaki disease, which is thought to come about when the immune system over-reacts to an infection.
This has raised concerns about whether it is safe for children to go back to school, with primary students in England expected in the classroom as soon as 1 June.
With some calling for schools to remain closed until September, a study review by scientists at University College London (UCL) suggests children who are exposed to the coronavirus may be 56% less likely to catch it than adults.
The government’s Scientific Advisory Group for Emergencies (Sage) announced the risk of children returning to the classroom is “very, very small, but not zero”.
Early research suggests the coronavirus is mild in four out of five cases, however, it can trigger a respiratory disease called COVID-19.
Coronavirus: Children a ‘very small per cent of confirmed cases’
“There is an increasing amount of data now available on children and COVID-19, and this is the first comprehensive study to carefully review and summarise what we do and do not know about susceptibility and transmission,” said lead author Professor Russell Viner.
“Our findings show children and young people appear 56% less likely to contract COVID-19 from infected others.
“Susceptibility is a key part of the chain of infection, and this supports the view that children are likely to play a smaller role in transmitting the virus and proliferating the pandemic, although considerable uncertainty remains.
“This new data provides essential evidence to governments around the world to inform their decision-making on whether to reopen schools and reduce or end lockdown measures.”
The scientists looked at more than 6,000 studies carried out all over the world, of which 18 were suitable for inclusion in their analysis.
They found youngsters were on average 56% less likely to catch the coronavirus from an infected person than those over 20.
Although unclear, the pathogen may not take hold as easily in young lungs. Exposure to milder strains of the coronavirus class, like those that cause colds, may also give children some immunity.
The scientists could not conclude whether children who are infected pass the coronavirus on as readily as adults.
They added, however, youngsters likely play a lesser role in the transmission of the virus because fewer become infected in the first place.
“It is well known children and young people make up only a very small per cent of confirmed clinical cases of COVID-19, in most countries, including the UK,” said Professor Viner.
“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.
“To understand susceptibility and transmission it was essential we looked at studies which trace and test all the close contacts of those with infection and at studies which screen whole populations for infections and not just those with symptoms.”
The scientists stressed the results have been released preliminarily and are yet to be peer-reviewed.
Peer-reviewing involves experts not involved in the research critiquing it in a non-biased way. Nevertheless, Sage reportedly considered the UCL team’s findings in its review.
UCL scientist Professor Chris Bonell described the studies they analysed as being “low” in number and of “mixed quality”.
Dr Michael Head from University of Southampton added: “This is a good quality systematic review and useful addition to the evidence base regarding the views that children are typically less likely to be infected than adults.
“However, there is still a key question that we do not fully understand and that is the role of children in transmission.
“It’s a key topic in the UK, with some children returning to school on 1 June.
“For example, many care home and domiciliary care staff will have school-age children, and it is vital we can be sure there will be no significant chain of transmission between children and then onto parents who work close to vulnerable populations.”
‘We must recognise this virus is with us and restart our lives’
On 22 May, the Independent Sage – an alternative to “official” Sage – said schools should not open on 1 June because there is “no clear evidence” it is safe.
“By going ahead with this dangerous decision, the government is further risking the health of our communities and the likelihood of a second spike,” said Sir David King, former chief scientific advisor and chair of Independent Sage.
“However we also recognise the decision of when to re-open our schools is a careful balance and it is vital for our young people to get back into the classroom as soon as it is safe to do so.
“The current climate is likely to disproportionately affect the most disadvantaged in society; therefore it is vital the government also considers innovative ways to help those who need it most.”
Independent Sage has argued schools should not reopen until local “test, track and isolate” systems are in place, which the UCL scientists agreed is important.
When asked if it is “safe” to open schools during a Science Media Centre briefing, Professor Viner said: “I believe it’s not helpful to make statements of safety as absolutes.
“There are safety issues in walking out the front door, there are safety issues getting in our car to drive our children to school.
“We must recognise this virus is with us and restart our lives in a way that balances safety with benefit.
“What we can do is partition risks.”
It has been suggested groups of children could attend school at different times, have socially-distant breaks or sit further apart at their desks.
Professor Bonell admitted we do not know how effective any of these measures will be at combatting the coronavirus outbreak, but added they may act “synergistically”.
“We need to put [in place] a range of measures that act in the same direction so we get synergy,” he said.
Children aside, Professor Bonell added it will also be important to ensure parents do not mix at the school gates.
A source involved with “official” Sage told the BBC: “It is totally impossible to say any change has no risk at all, as long as virus is circulating in us, and there is no immunity, there is some risk.
“The risk is low and in this case it is not particularly higher than in other environments.”
Only government authorities in England have suggested youngsters may be back in June.
What is the coronavirus?
The coronavirus is one of seven strains of a virus class that are known to infect humans.
Others cause everything from the common cold to severe acute respiratory syndrome (Sars), which killed 774 people during its 2002/3 outbreak.
Since the coronavirus outbreak was identified, more than 5.1 million cases have been confirmed worldwide, according to Johns Hopkins University.
Of these cases, over 1.9 million are known to have “recovered”.
Globally, the death toll has exceeded 333,000.
The coronavirus mainly spreads face to face via infected droplets expelled in a cough or sneeze.
Symptoms include fever, cough and slight breathlessness.
The coronavirus has no “set” treatment, with most patients naturally fighting off the infection.
Those requiring hospitalisation are given “supportive care”, like ventilation, while their immune system gets to work.
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