Children's immune systems protect them from severe cases of Covid-19. This is what a study conducted by the Australian research institute Murdoch Children's Research Institute (MCRI) points out and published in the journal Nature Communications.

According to the research, the innate immune system of small children is faster to attack the virus compared to that of adults. Melanie Neeland, a doctor at the MCRI, says that it was already possible to observe that the occurrences of Covid-19 in children were milder, but it was not yet known which immunological mechanisms supported this protection. “Children are less likely to become infected with the virus and up to a third are asymptomatic. This is very different from the higher prevalence and severity observed in small children for other respiratory viruses ”, he says.


The study was carried out in Melbourne, Australia, and involved analyzes of 48 children and 70 adults from 28 different households infected or exposed to new coronavirus. Responses were monitored during the acute phase of infection and up to two months after exposure. "Understanding the underlying age-related differences in the severity of Covid-19 should provide important information and opportunities for prevention and treatment even for future pandemics," says Melanie.

Oxford vaccine to be tested in children
Children's immune systems prevent the virus from reaching the tissues. Credit: Melinda Nagy / Shutterstock

Covid-19 virus is eliminated before installing

Melanie reinforces that the speed in presenting an immune response in the children's body is crucial for the cases to be milder. According to her, the study suggests that cells that fight infections quickly eliminate the virus and do not even allow it to install itself in tissues. 

This reaction is not seen in adults. “Coronavirus infection in children was characterized by the activation of neutrophils - specialized white blood cells that help heal damaged tissues and resolve infections - and by the reduction of first response immune cells, such as monocytes, dendritic cells and natural killer blood cells. " 

The results reinforce the conclusion of previous MCRI research, which found that three children developed similar immune responses after being exposed for a long time to the new coronavirus. At the time, the parents had a positive diagnosis of Covid-19, but the tests of the children showed negative results. For the researchers, this is a sign that they were able to create a highly effective immune response to prevent the virus from replicating. 

Source: Medical Press 

Have you watched our new videos on YouTube? Subscribe to our channel!