The scientific journal The Scientist has published some hypothetical theories of a group of scientists specialized in the study of coronaviruses, explaining the possible reasons why children do not develop the serious symptoms associated with Covid-19 disease.

The scientists attributed the main reasons to: the modernity of children's immune systems, and the high rate of ACE2 receptors on cells, which are the receptors that the virus uses to bind to the lung cells to dislocate its protein sheath and inject its DNA into it, which simultaneously regulates the strong immune response, in addition to Children have had previous infections from other coronaviruses.

The site stated that no injuries were found among children in the Chinese city of Wuhan between November 2019 to the second week of January 2020. In another study of 1099 patients in China, only 0.9% of confirmed cases were under the age of nine, and ranged from 1.2 ages % Of those affected are between 10 and 19 years old.

Stanley Perlman, an immunologist at the University of Iowa in the United States of America, said: “The data from animal experiments support the idea that children become infected, but the disease does not develop them, in order to equal the rates of the virus in both mice of small and old ages, and yet the small does not Get sick ».

One explanation links the seriousness of symptoms of Covid-19 disease to the age of the immune system, as "the progress of a human uncle is accompanied by the aging of his immune system."

Some scientists point to the important role that T cells play in overcoming infection, as results of experiments published by Perelman and his colleagues in 2010 demonstrated the role of T cells in eliminating the SARS virus, and says, “We need antibodies and response from T cells to eliminate Covid-19 infection. And this is what the immune system does in children and their highly efficient T cells do. ”

"Maybe T cells formed in the early stages of life may have a higher capacity to fight Covid-19 disease," Kingston Mills, an immunologist at Trinity College at Dublin University in Ireland, suggested that excess production of T2 cells in children may be responsible for protecting them from Inflammatory responses and violent immune response to Covid-19 disease.

Both the SARS Cove-1 virus that causes SARS and the SARS Cove-2 virus that causes Covid-19 use ACE receptors, as the virus’s protein thorns are attached to this receptor on the host’s cells to be able to take off their protein sheath and inject their genetic material, and these receptors are common In the lower part of the lung, which explains the incidence of pneumonia and bronchitis in Covid-19 patients, and a recent study showed the presence of these receptors significantly in the mouth and tongue, which facilitates the entry of the virus into the host, despite the low levels of those receptors in the elderly, This does not protect them from infection, but rather They put them at greater risk, according to the assumptions of Barrick and Hongping Jia of Johns Hopkins University School of Medicine.

Explanations correlate the severity of corona with the age of the immune system