How does the children’s immune system work against Covid?
[ad_1]
We know that the risk of death and hospitalization in the event of Covid19 increases with age, in fact most of the deaths occurred in people over 65 years of age. Children are certainly not immune to Covid19 but they experience a milder disease on average, why?
How the immune system works
The immune system is made up of a series of organs, cells and mediators whose purpose is to defend the body from external agents that can cause infections. Infants have an underdeveloped immune system and in fact receive passive immunity through mother’s milk, the full development of the immune system occurs around 8 years of age.
During adult life the immune system is active in recognizing and destroying potential internal and external threats. Around the age of 60, the decline of the immune system begins, which will be less efficient in managing infections and pathogens.
We’re all getting sick: I’ll explain why viruses attack us
by Aureliano Stingi
Why, despite an underdeveloped immune system, children are little subject to Covid19?
Two scientific papers published in recent weeks try to answer this question.
The first study concerns a population of children who underwent tonsillectomy and adenoidectomy in the period between September 2020 and January 2021. The researchers analyzed the histological samples removed and found traces of the passage of Sars-CoV2, in fact in the removed tonsils in addition to the presence Of B and T lymphocytes i have been found germinal centers.
The germinal centers are structures of our immune system responsible for the creation and training of B lymphocytes that will give life to antibodies. In practice, germinal centers are temporary barracks where soldiers are trained in the event of an attack. The fact that children have developed germinal centers in their tonsils and adenoids could explain their ability to keep SARS-CoV2 infection at bay. In fact, the presence of specific germinal centers in the upper airways of children means that the immune system was activated by the passage of the virus and remained active for weeks after infection. The germinal centers can remain active for months or years and in case of infection by the same pathogen they are ready to resume the production of B lymphocytes and antibodies.
COVID WATCH The complete archive
In adult subjects, the activation of germinal centers is mainly observed in vaccinated subjects and little in recovered subjects. This explains why even in case of recovery it is advisable to get vaccinated.
The second article focuses on T lymphocytes involved in the response to Covid19 in adults and children. In fact, researchers have found a greater presence of T lymphocytes in children, able to react to Sars-CoV2 than in adults. Curiously some children who had never been exposed to Sars-CoV2 possessed T lymphocytes capable of binding the virus and destroying it.
This phenomenon may be the key to understanding why children are more inherently protected than adults. In fact, children in the first years of life are subjected to hundreds of pathogens to which their immune system is still not used to and trained. Just think that a child becomes infected with seasonal coronaviruses up to three/four times a year. This continuous exposure to pathogens stimulates the production of broad-spectrum T lymphocytes that recognize cold coronaviruses but also Sars-CoV2.
In summary: in the upper airways of children recovered from Covid19 germinal centers capable of producing large quantities of B lymphocytes and antibodies as needed develop, furthermore children have a broad spectrum of T lymphocytes capable of recognizing various coronaviruses including Sars -CoV2.
Covid, still no decision in Italy on recalls for children between 5 and 11
by Fabio DiTodaro
So if children are naturally protected from Covid19 why do we have to vaccinate them?
Despite some beneficial features of the children’s immune system, vaccination is always recommended for a number of reasons:
- Infection with Sars-CoV2 in an unvaccinated subject is always an unknown risk
- Not all children form germinal centers and have broad spectrum T lymphocytes
- The vaccine safely induces the production of germinal centers and creates a large repertoire of T lymphocytes
REF:
https://www.nature.com/articles/s41590-021-01089-8
https://www.nature.com/articles/s41590-022-01367-z
Aureliano Stingi, doctor in molecular biology works in the field of precision oncology. He collaborates with the World Health Organization in the battle against Covid19-themed fake news
Instagram: Aureliano _Stingi Twitter: @AurelianoStingi
[ad_2]
Source link
