Children reportedly produce weaker antibodies against Covid-19

Reading time: 2 min – Spotted in the New York Times

A new study suggests that children with Covid-19 produce fewer antibodies than adults and that they are less effective. Which, paradoxically, could explain why younger people recover faster from a Covid-19 infection.

Studies have already indicated that a strong immune response can cause more severe forms of Covid-19. The weak immune response produced by the children could therefore make us understand why they are able to defeat the virus before it wreaks havoc. This would also explain the absence of Covid symptoms in many children and the low transmission rate between them.

Donna Farber, an immunologist at Columbia University, co-author of the research, analyzed four groups of patients with her team:

• 19 recovering adults recovered from Covid without being hospitalized;
• 13 adults admitted to hospital with severe respiratory distress due to Covid;
• 16 children hospitalized with multisystem inflammatory syndrome (near Kawasaki);
• 31 infected children without syndrome and half of whom have no symptoms.

Different antibodies according to age

In each group, the individuals showed antibodies. However, they were not the same depending on whether the patients were children or adults. A particular type of antibody, IgG, was found in both groups of children. Several types have been isolated in adults, some of them more neutralizing, in those with the most severe symptoms.

How to explain this paradox? “There is a link between the extent of your immune response and the extent of the infection – the more severe the infection, the stronger the immune response, as more cells and immune responses are needed to clear a dose. superior to a pathogen, expose Farber. Children’s bodies are particularly well suited for detecting pathogens for the first time. This is how their immune system is designed. Children have many naive T cells, capable of recognizing all kinds of new pathogens, while older people are more dependent on their immunological memory. Adults are not as adept at responding to a new pathogen as children. ”

The hypothesis is the following: for children, Covid-19 is a disease like any other, which the immune system can easily manage. Scientists were able to formulate this from two observations on their bodies: only good antibodies were generated and their cells have fewer ACE2 receptors (points of entry for the virus) than those of adults.

However, the research team reiterates that the results should be used with caution as they represent only a small sample at a time T. Other studies are underway to better understand the immune response of children, in order to improve that of adults.