Scientific studies have shown that the mild course of COVID-19 leaves behind immune cells that are capable of independently producing antibodies against coronavirus throughout their lives.
The research was carried out by scientists at the University of Washington School of Medicine in St. Louis. They argue that the protection that arises after a previous illness reduces the risk of re-infection to a minimum. The results of scientific work can be found in the journal Nature, where they are published.
The research experiment involved 77 volunteers who donated blood one month after infection and then at three-month intervals. Only six of them were hospitalized, the rest were mildly ill. Bone marrow samples were taken from 19 participants 7 months after infection. Five donated the sample again, after another 4 months.
In the first few months after infection, scientists expectedly found that the level of antibodies in the blood of the participants in the experiment fell, but later it leveled off. This decline is independent of a weakness in the immune system, as cells capable of producing antibodies remain. What’s more, researchers found them 11 months after infection! They migrate to the bone marrow and constantly saturate the blood with antibodies, protecting the body from new infections.
In connection with the data obtained during the study, scientists believe that this is the case with people who have had asymptomatic coronavirus. Now it is necessary to find out how protected those who suffered from COVID-19 in a severe form are protected from re-infection.