According to research, a weaker immune system is not the cause of lung failure in severe COVID-19 infections. A study was conducted on specific antibodies and T cells occurring in recovered, seriously ill, and the deceased Covid-19 patients. A comparable immune reaction was found by the researchers in the clinical follow-up. Antibodies and T-lymphocytes are one of the most important elements of the immune defense against viruses. They prevent viruses from entering the host cell by binding to certain virus receptors. They also mark the infected cells for other players in the immune system, which can kill the infected cells.
On the other hand, virus-specific T-lymphocytes can kill infected cells directly and highly efficiently. This is how the immune system works. But in the previous weeks, a study conducted on the SARS-COV-2 specific T cells was detected in patients recovered from COVID-19. On the contrary, some studies indicate that an excessive immune response might be the cause of severe Covid-19. The role of Sars-Cov-2 specific T-cells in this exaggerated immune response is still unclear.
The study was conducted during the progression of the infection and researchers found that not only was the T cell and antibody in patients who had recovered but a stronger immune response in patients who had been critically ill and people who suffered lung failure. Even though further studies are necessary to understand the mechanism of T-cells the data from this study suggests that excess T-cell response can cause immunopathogenesis leading to COVID-19-related lung failure.