By DR. EDUARDO GONZALES
Just about the only good thing about Covid-19 that one can think of is that it spares most children. It’s not that children do not get infected with the disease because they are likely to be as susceptible to the virus as adults, but they hardly get the severe form of the disease. This phenomenon, which was first noted in China, is true worldwide. In the US, by the time 51,000 deaths have occurred only three of the fatalities were below 17 years of age, and all three had pre-existing medical conditions.
Available epidemiologic data clearly show that compared to adults, children 17 years and below, are less likely to experience the typical symptoms of infection, including fever, cough, and difficulty in breathing. They are also less likely to need hospitalization and less likely to die of Covid-19.
Studies in China and the US, including one published in the medical journal Pediatrics, showed that more than 90 percent of children infected with Covid-19 had no or only mild to moderate symptoms. This is odd because pathogenic viruses, such as those that cause flu, dengue, polio, and smallpox, affect children and the very old more than young adults.
A probable reason why children don’t get the severe form of Covid-19
We do not exactly know yet why children can fight off the disease better than adults, but experts have one plausible theory: In children, the immune system does not, or cannot, mount the aggressive immune reaction to the virus (called cytokine storm) that it does in some adults. Cytokines are proteins, produced by cells of the immune system that serve as messengers among cells. The immune system is the human body’s army—it is made up of billions of cells that have access to numerous forms of weapons. Normally, when the human body encounters a pathogenic microorganism, the cells of its immune system attack the invader in a very orderly, well-organized manner, and with just enough force to eliminate the invader. But, sometimes, for a variety of largely unknown reasons, an overwhelming amount of cytokines are released by the immune cells (i.e., a cytokine storm develops). The cells get confused and go berserk. They essentially transform into an unruly mob that destroys everything in their path, including healthy tissues. They injure blood vessels and blood clots develop in the blood vessels. The various organs get inflamed and damaged, sometimes irreparably, and they start to fail.
In Covid-19, increasing evidence suggests that a good number of those who get seriously ill or die do so because of a cytokine storm. The cytokines that stimulate the immune cells become too abundant causing the immune cells to start attacking healthy tissues giving rise to widespread inflammation. The immune cells attack the lungs early, and so severely that scar tissue called fibrosis forms. Blood vessel walls leak to let immune cells into surrounding tissues, but in the lungs, they get so leaky that the lungs may fill with fluid, and blood pressure drops. Blood clots develop throughout the body impairing blood flow to the various organs leading to gradual failure of these organs.
Why children with Covid-19 do not or are not able to mount hyper-reactive immune responses is not known yet. But it’s a good thing they don’t.
Children can be asymptomatic sources of infection
Whereas in many coronavirus infections such as MERS and SARS, only sick individuals can spread the disease, in Covid-19, all infected people, even if asymptomatic, are communicable. Hence, children potentially can be asymptomatic carriers of the disease that is why precautions should be observed so that children don’t get infected despite being less affected by the disease.