Covid-19 and Kids: What Do We Know?

It is unusual for the virus to be less severe for children than for adults. However, for SARS-CoV-2, children account for only a small proportion of serious cases.

Researchers at Yale University are working hard to understand why. Their findings will help them better understand the virus and look for possible treatment options.

A paper entitled “Reduced Development of COVID-19 in Children Reveals Molecular Checkpoints Gating Causes to Uncover Potential Treatments” was recently published in the National Academy of Sciences (PNAS) proceedings. It was published and showed amazing immunity to the virus in children.

Dr. Naftalikaminsky, professor of internal medicine donated by Boehringer Ingelheim and director of lung, critical care and sleep medicine, details that factors such as allergies, asthma, colds and existing vaccines can cause protective effects. I shared it.

Meanwhile, Professor Astocarrie Lucas of Immunobiology at Yale University responded to Covid-19 with the blood of a small proportion of children who developed a rare condition known as multiple inflammation syndrome (MIS-C) in children. I am studying a sample.

In her lab, she analyzes blood samples for molecular and genetic cues to find out why a subset of certain children are at greatest risk while others are relatively safe. I am.

A study published in Science Science Translational Medicine, led by Professor CNH Long Immunology and Internal Medicine of Yerkeban Herold, shows that children diagnosed with Covid-19 display two specific immune system molecules at higher levels. This is a factor that can lead to better health outcomes.

“This is different from other viruses that have serious effects on children,” Kaminsky said. “This is an interesting challenge and can affect treatment.”

In a PNAS paper, researchers point out that childhood allergies and asthma may have protective effects. When the body responds to triggers for allergies and asthma, the immune system releases Th2 cells, which increase the type of cells called eosinophils in the blood and tissues.

This allergic inflammation has been shown to dramatically reduce the levels of a major receptor on the Covid-19 molecule known as ACE2. They added that a study of 85 elderly people who died of Covid-19 in China showed very low levels of blood eosinophils.

“Initially, we were concerned about the effects of Covid-19 on children with asthma,” Kaminsky said.

According to the Center for Disease Control and Prevention, 7.5% of children under the age of 18 (5.5 million) in the United States have asthma. “But in reality, people with asthma are less infected than other chronic lung diseases, and asthma does not appear to be a risk factor when infected,” he added.

Instead, risk factors known to exacerbate Covid-19 outcomes include age, obesity, high blood pressure, and heart disease.

“Common colds may provide protection”

The more often children are exposed to common colds, the more protection they can provide. Coronaviruses are a large family of viruses, named after their crown-like shape under a microscope. SARS-CoV-2, which causes COVID-19, is another.

If one virus interferes with the replication of the second virus, it is believed that exposure to the common cold can cause the virus to interfere.

Exposure to colds, and more common exposure to children such as croup, is associated with decreased expression of the ACE2 COVID-19 receptor.

Studies show that children who are symptomatic with Covid-19 may have high viral load in the nose, but low levels of ACE2 make them less likely to infect the lungs. This means that the virus can be easily spread, but it is less likely to develop serious symptoms.

Kaminsky added that there is even evidence that the vaccine can provide protection.

According to a Pentagon official survey, the 2017-2018 seasonal flu vaccine produced a “statistically significant” number of individuals who tested positive for the common cold-related coronavirus.

He said that if future influenza vaccines are designed to increase the common coronavirus, this phenomenon may actually protect SARS-CoV-2 to some extent through “cross-reactive immunity.”

Severe reaction for a rare number of children

Not all children are protected from the worst effects of Covid-19.

Her team of pediatric immune disease researchers at Lucas and Yale University are investigating cases of rare children seriously affected by the virus.

Specifically, we examined children who were asymptomatic during SARS-CoV-2 infection, but after a few weeks they developed high fever, vomiting, abdominal pain, and sometimes shock, resulting in a condition called MIS-C. It was. As of September 17, there were 935 confirmed MIS-C cases in the United States, with 19 deaths.

Lucas’ lab, which enrolled 16 pediatric MIS-C patients, analyzed immune cells in the blood at the single-cell level and analyzed thousands of blood proteins to understand what was happening. I am.

“Most of the time, our data now show that it’s not a syndrome,” she said. “For example, there were no signs of active viral or bacterial infection during acute MIS-C.”

They also collect saliva samples from their parents and compare them to their children’s samples, which may reveal information about genetic variation.

“We are looking for haystack needles that may be causing this rare symptom,” Lucas said, “so far, there is no evidence that this is being done in the family. No. I don’t know of any cases where two children in the family developed MIS-C. “

What they know is that they have high inflammatory markers and most patients respond well to immunosuppressive therapies such as steroids. Additional findings will be published in the coming weeks on MedRxiv, a preprint server founded by Yale scientists who publish their studies prior to peer review.

Children appear to be largely protected from the immediate effects of Covid-19, but Kaminsky and the authors continue to warn. They point out that pandemics and social distance affect immune system maturation, psychological health, education, and childhood obesity.

“We know that children’s health is strongly affected by socio-economic downturns,” Kaminsky said, “and don’t overlook this potential detrimental consequence.”