Is it true that children almost do not get coronavirus? And if so, why?

The news that a baby in China was diagnosed with a coronavirus on the second day after birth was circulated on February 5 around the world.

This is the smallest patient with such a diagnosis. The outbreak has already claimed the lives of more than a thousand people; in all, more than 40 thousand people have been diagnosed with coronavirus. However, there are very few children among the diseased. It can be said, so far these are isolated cases.

Most of the cases are residents of China, but cases of infection with coronavirus have been reported in more than 30 countries.

A recent study published in the Journal of the American Medical Association, a medical journal, said the disease mostly affected people between the ages of 40 and 59.

“Cases among children are very rare,” the study said.

But why is this happening?

Asymptomatic course of the disease?

There are already many explanations for this phenomenon, but experts do not yet have an exact answer to the question of why this disease is diagnosed much less frequently in children.

“For reasons that are not yet clear to us, children either do not catch this infection, or the disease proceeds in a milder form,” says Ian Jones, a professor of virology at the University of Reading.

This may mean that children tolerate the disease in a much milder form, sometimes the symptoms may hardly appear – in such cases, parents, as a rule, do not take their children to the doctor.

Lecturer at University College London Natalie McDermott agrees with this version.

“The immune system of children under five years of age and adolescents is usually very well prepared to fight viruses. They can become infected, but the disease will go on in a milder form, or it may be an asymptomatic course of the disease,” says Natalie McDermott.

The same situation was observed during the SARS outbreak in 2003. Then 800 people became victims of the virus – 10% of all infected. That infection also almost did not affect children.

Is it about the holidays?

Natalie McDermott suggests that the low prevalence of the disease among children can also be explained by timely preventive measures – schools and kindergartens were closed during the outbreak, and the outbreak started during the New Year holidays.

School holidays in almost all regions of China were extended until the end of February.

In addition, according to McDermott, adults are working hard to protect their child from infection.

“Adults protect children by protecting them from possible infection, but if there is a sick person in the house, they try to isolate the children from it,” says Natalie McDermott.

She believes that in the case of further spread of the virus, when contacts with infected people will be more difficult to avoid, the situation may change for the worse, and among children there will be more infected people, because it will just be more difficult to isolate them.

So far, the rapid spread of coronavirus has not led to an increase in the incidence among children.

If we draw an analogy with the SARS outbreak, we can recall that researchers at the US Centers for Disease Control and Prevention concluded that children under 12 years old were less susceptible to disease and needed less treatment in a hospital.

Is coronavirus more dangerous for adults?

Although there are few confirmed cases of coronavirus among children, experts emphasize that it is impossible to talk about the presence of special immunity in children against coronavirus.

A more likely explanation for the low incidence of coronavirus among children may be the following fact: the most common complications of the disease (e.g. chickenpox) are more dangerous for adults than for children. Adults suffer these complications in a more severe form.

“This is a more plausible explanation than the fact that children have a special immunity against coronavirus,” says Andrew Freeman, an expert on infectious diseases at Cardiff University.

“This may be due to the fact that doctors do not check for the presence of the virus in those children who do not have pronounced symptoms of the disease, and those who have weak symptoms,” Freeman adds.

Oxford University Statistical Epidemiology Expert Christle Donnelly agrees with this view and cites Hong Kong SARS outbreaks.

“Our colleagues then came to the conclusion that young children suffered the disease in a much milder form,” the expert notes.

Chronic diseases

The immune system of adults who have any kind of chronic illness is less likely to cope with the virus. Diabetes or diseases of the cardiovascular system lead to a more severe course of the disease and more serious complications.

“Pneumonia (one of the most common complications of coronavirus) is usually seen in patients with an initially weakened immune system. The same thing happens with flu and other acute respiratory viral infections,” Ian Jones explains.

As it turned out, approximately half of the patients in the Wuhan hospital who were diagnosed with coronavirus have chronic diseases.

Aren’t children the easiest to catch infections?

Children are known to be prone to pick up respiratory viral infections and serve as a source of their spread among their peers, says Ian Jones.

Therefore, it seems to us that it is children who are most vulnerable to viruses. But the situation with coronavirus does not confirm these concerns.

Perhaps the children really have a stronger immune system, or the virus is less aggressive when it enters the child’s body, so the disease is often asymptomatic and the parents do not take the child to the doctor. Accordingly, there are fewer reported cases of the disease among children.

In the near future we will have a clearer idea of ​​why children in the case of coronavirus seem more protected.

Nikolai Voronin, correspondent of the Russian BBC Service for Science and Technology

The fact that children’s immunity is more flexible and easier to adapt to new diseases is a well-known fact. That is why, for example, measles or chickenpox are relatively easily tolerated in childhood, but can cause a lot of complications in adults.

Just a couple of weeks ago, Canadian scientists published a study proving that the first type of influenza virus that a child encounters in infancy will forever determine his body’s ability to fight respiratory viral infections.

And this means that during an epidemic, doctors can predict in advance how vulnerable a particular person is, depending on his year of birth and then the most common strain of the virus.

“The primary immunity of people to viruses like flu or even coronavirus can have a huge impact on the risk of infection,” emphasizes one of the authors of the study, immunologist Matthew Miller. “And it’s very important to understand how this primary immunity either protects people from disease, or, on the contrary, makes them more vulnerable because it helps us identify the most-at-risk populations during seasonal epidemics and new outbreaks of the disease. “

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