It is clear that children's immune cells are more responsive to the new coronavirus than adults, which is one of the reasons why children are less likely to become severely ill.

Recent research shows that childhood immune cells are more responsive to the new coronavirus than adult immune cells.

Shared B cell memory to coronaviruses and other pathogens vary in human age groups and tissues | Science

We May Have Found a Cellular Difference That Protects Kids From COVID-19

The human immune system is composed of multiple cells such as T cells , B cells , and microphage. However, not all people have the same cells in their blood.

Since B cells remember pathogens that the body has encountered in the past, cell receptors mutate to make immune cells, depending on what kind of disease the body has had in the past. A research team at Stanford University investigated how these immune cells differ between individuals and how they relate to human lifespan.

The research team collected 114 blood samples from healthy adults, 93 blood samples from 51 children aged 1-3 years, 12 cord blood samples, and 8 blood, lymph node, and spleen samples from organ donors. Analyze each.

Blood collected from children before the pandemic of the new coronavirus (SARS-CoV-2) has more B cells in the blood than adults, even though it has never been exposed to the virus. Has also been shown to frequently bind to SARS-CoV-2.

Although this study is in its infancy, it may provide clues as to why children are far less likely to become more severe than adults when infected with the new coronavirus infection (COVID-19). There is.

'Children are less likely to have a new coronavirus infection,' confirmed by the Centers for Disease Control and Prevention (CDC)-GIGAZINE

A team studying the differences in immune cells between individuals said, 'Children usually develop milder symptoms after being infected with SARS-CoV-2 than adults. This is due to viral receptor expression and immune response. It may be due to the difference, 'he wrote in the paper.

According to the research team, children who develop COVID-19 have lower antibody titers in contrast to adults, and have more immunoglobulin G (IgG), which is specific to the spike protein on the surface of SARS-CoV-2.

B cells, a type of white blood cell, retain information about previously infected pathogens at cell surface receptors. These receptors provide an immune response to the pathogen by allowing B cells to bind to a bit (antigen) of the pathogen that they can recognize like a piece of a puzzle. In addition, these receptors can mutate into other receptors that destroy pathogens when cells or viruses invade the body.

When the research team examined B cell receptors, it was found that children's B cells carry more clones than adults against viruses and bacteria that have invaded the body in the past. It was also found to have more B cells that can work effectively against the virus without being infected with SARS-CoV-2.

The research team explained why children do not become severe when they develop COVID-19, 'to clone when children are exposed to other coronaviruses so that they can also respond to SARS-CoV-2. Probably due to mutation. '' Past exposure to coronavirus may stimulate cross-reactive memory, so we assume that cloning reactions may be most frequent in childhood. ' It states.

However, more extensive research is needed because there may be more factors in children who have mild symptoms when infected with COVID-19.

in Science, Posted by logu_ii