Monday, February 26

Coronavirus: Why are children less at risk?



Age is a known risk factor for coronavirus complications. In the 10 weeks from 28 March to 5 June, six people aged 14 or under died with the infection in England and Wales.

This is compared to 24,511 in those between 75 and 90 years old. Concerns have been raised that while the vast majority of youngsters recover from the coronavirus, they may still be capable to passing it to vulnerable adults, hence why officials stressed grandparents should not be called upon to provide childcare.

This has been up for debate, however, with some research suggesting children are less likely to catch the coronavirus in the first place, let alone become seriously ill.

Early research suggests the coronavirus is mild in four out of five cases, however, it can trigger a respiratory disease called COVID-19.

Why do children develop less severe coronavirus complications?

The vast majority of coronavirus deaths worldwide have occurred in the elderly. Italian scientists looked at more than 1,000 children with the infection.

Just one, a 13-month-old baby, developed a severe case of COVID-19 and went on to make a full recovery. Similar findings came to light in a small study of 34 young coronavirus patients in China.

All the children had either mild (18%) or moderate (82%) signs of the infection. Youngsters are thought to have sharper immune systems, which helps them defeat pathogens.

As we get older, so do our immune systems, which results in them becoming slower and less effective at fighting off infections that we have previously come across, Professor Arne Akbar from the British Society for Immunology previously said.

The opposite is true, however, with seasonal flu. Young children make up those eligible for a free flu vaccine on the NHS, with the virus having potentially devastating consequences due to their underdeveloped immune system.

Scientists from Mount Sinai Hospital in New York have suggested the cells that line a child’s nose may also have something to do with it.

After looking at cell samples from people between four and 60 years old, they found the gene that produces the protein ACE2 was expressed at lower levels in the youngsters, increasing with age. ACE2 is the receptor that helps the coronavirus enter the body.

While most children with the infection escape unscathed, the coronavirus outbreak has coincided with a rise in a mysterious inflammatory disease in young people.

NHS doctors were told to look out for signs of “multi-system inflammation” after intensive care units in London saw eight children with unusual symptoms, some of whom tested positive for the coronavirus.

A study later revealed how 10 children developed a “rare inflammatory disorder” in the Bergamo province of Italy after the outbreak emerged in the north of the country.

Eight of these youngsters tested positive for coronavirus antibodies, with the Italian doctors wondering if the other two were false-negatives.

“There is apparently a small risk but no grounds for panic,” Professor Alastair Sutcliffe from UCL previously said.

Are children less likely to catch the coronavirus?

While children rarely suffer ill effects from the coronavirus, experts have questioned to what extent they catch the infection in the first place. Scientists from UCL found youngsters are 56% less likely to catch the coronavirus than someone over 20.

A team from the London School of Hygiene & Tropical Medicine (LSHTM) later duplicated these findings, estimating susceptibility to infection in individuals under 20 years of age is approximately half that of adults aged over 20 years.

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.

To what extent do children spread the coronavirus?

Scientists have been unable to conclude whether children who are infected pass the coronavirus on as readily as adults.

It has been suggested, however, youngsters likely play a lesser role in the transmission of the virus because fewer become infected in the first place.

The coronavirus mainly spreads face to face via infected droplets expelled in a cough or sneeze. Someone with no or mild symptoms would theoretically transmit less of the virus as a result of them not actively coughing or sneezing.

Speaking of the LSHTM study, Professor Mark Woolhouse from the University of Edinburgh said: “[The scientists] were not able to determine whether young people are also less infectious, though this could be the case if infectiousness is linked to the severity of symptoms”.

Anyone with the coronavirus’ tell-tale fever, cough, or loss of taste or smell has been told to self-isolate entirely at home for seven days, while other members of their household must do so for two weeks.

If an unsuspecting person does not have these symptoms, they are free to go out, unwittingly putting others at risk. This was part of the rationale behind Boris Johnson’s decision to temporarily close schools on 20 March.

The move was met with both praise and criticism. A study by University College London argued children are not the main drivers of infection, with closing schools having a marginal effect.

Some pointed out, however, that the closure is combined with extreme social distancing during the UK’s lockdown.