1. The novel coronavirus (nCoV) enters the body by binding to ACE2 which is found in cells of the lungs, intestines, heart and kidneys between the nose and throat. With age, the presence of ACE2 increases in the area between the throat and nose and the inside of the lung wall, and because of this, it is able to carry more nCoV into the body. This is the reason why the risk of infection is lower in younger people. According to animal studies, ACE2 protects against nCoV-associated lung damage. When nCoV reaches cells via ACE2, the size of ACE2 is reduced and its protective ability is also reduced, making it easier to infect the body.
2. The inner lining of blood vessels is called the endothelium, and the mechanism of blood clotting in children is different from that in adults, so they are less likely to have a heart attack or stroke.
3. In most people, antibodies to this common coronavirus are produced in early childhood. Antibodies already present in the body help the new species of coronavirus enter cells and make adults more susceptible to the virus, causing more infections to spread within them. This is called increased antibody dependence (ADE). Children with Covid-19 have fewer ADEs than adults.
4. Aging is associated with a decrease in the innate and adaptive immunity in the body and therefore the body becomes weak in fighting viruses. Then, this innate immunity and adaptation is stronger in children, so their bodies are more susceptible to infection.
5. Other diseases such as diabetes, hypertension, heart disease, COPD etc are less in the body of children. Because of this disease, Covid infections are more common in adults.
6. Vitamin D deficiency is also a cause. Vitamin D has anti-inflammatory and anti-oxidative properties and its deficiency is more common in adults than in children.
7. The respiratory tract and intestines of children have more microbes such as bacteria and viruses, etc. than adults, which fight the coronavirus in the cells harder and do not allow them to enter the cells.
8. A hormone called melatonin, which has anti-inflammatory and anti-oxidative properties, is found in high amounts in children and decreases with age, resulting in the effects of corona infection on young children.
9. Compared to adults, the effectiveness of BCG and other vaccines given to children is there and because of this also the risk of infection in them is reduced.
10. Children have less nosocomial exposure to work, travel, and shopping than adults. If you go out a lot, you will get more infections. (is the most acceptable reason in my opinion)
How can we protect our children from nCoV infection?
As we adults protect ourselves. Distance from the body, wearing a clean mask that fully covers the nose and mouth, maintaining hygiene, not going to crowded places, and getting vaccinated. If more young people and adults are vaccinated, the infection in children will also decrease. Then, now there is a vaccine for children over the age of two. (Dr. Niket Rai is MBBS & MD and affiliated with Maulana Azad Medical College and Lok Nayak Hospital, New Delhi.)