Using a mathematical model, the staff of the Department of Molecular Microbiology and immunology analyzed the body’s immune response to COVID-19 and compared it with the processes in ordinary flu.
They noted that in a standard viral disease, the innate immune system begins to work immediately after infection, destroying the infection and the so-called target cells damaged by it. This prevents further spread of the virus and cleanses the body. If the disease remains, then after some time, the adaptive immune system is triggered.
As the researchers found out, in the case of coronavirus, the acquired immunity is activated even before all the target cells of the upper respiratory tract are destroyed. This does not allow the innate immune system to cope with the infection quickly and leads to an overload of the immune system.
“Longer viral activity can trigger an overreaction of the immune system, called a cytokine storm, which kills healthy cells, causing tissue damage,” says Weiming Yuan, one of the authors of the paper.
According to the researchers, the interaction of innate and adaptive immunity temporarily reduces the viral load on the body, which is why patients experience short-term improvement.
“However, if the body is not completely cleared of the virus and the target cells recover, the infection can attack it again and reach another peak,” explained another study author, Sean Duffy.
This is why some patients with COVID-19 have symptoms that subside for a while and then relapse.
Based on the results obtained, scientists proposed suppressing the body’s immune system with immunosuppressants in the early stages of the disease.
“We will be able to delay the adaptive immune response and prevent it from interfering with the innate immune system, which will allow faster elimination of the virus and infected cells,” Du said.
As the researchers added, to confirm the results of mathematical modeling, it is vital to measure viral load and other biomarkers daily in patients with COVID-19. Also, additional clinical trials are needed to introduce such a treatment, they stressed.