The results are still a preprint – a preliminary publication, so they have not yet been reviewed by other scientists. However, the research team led by Professor Martina Sester believes that they are so important that the research results have already been published. Because they showed, in contrast to previous statements, that people who were seriously ill with Covid-19 then give a stronger immune response.
For this purpose, Sester and colleagues from infection medicine, internal medicine and hemostaseology (blood coagulation) at the Saarland University Hospital examined the patients’ T cells. “Just like antibodies, T cells are part of the body’s specific immune response, which is specially tailored to a particular pathogen,” explains Sester.
Comparison of severe and mild cases
According to Sester, the study was the first to compare severe and mild disease courses. “So far we have assumed that patients with severe disease have the poorer immune system and those with mild symptoms have the better,” says the immunologist. “But it’s exactly the other way around.” The more severe the course, the more T cells and the greater the number of specific antibodies against Sars-CoV-2.
However, there is also a problem in this, because the immune system “then has great difficulty in reducing the excessive immune response again when the viral load drops and the replication of the viruses, for example in the lung tissue, could be stopped,” says Sester. If the virus disappears, T cells and the antibodies can direct themselves against the body’s own tissue like in a kind of autoimmune reaction, which can lead to organ damage.