"Immune" against Corona?
Why some people don't get the virus at all
Created: 04/14/2022, 21:12
By: Yasina Hipp
T cells can make it difficult for the coronavirus to multiply.
© picture alliance/dpa/ZUMA Wire/Niaid-Rml
The corona infection numbers are currently at a very high level.
Many thousands of people are infected every day - but some are spared.
Why is that?
London – After two years of the pandemic, everyone now knows someone who has already been infected with the corona virus.
Given the current high rate of new infections every day, it is almost more difficult to identify someone who has not yet contracted the virus.
Studies have already shown that people with blood group 0 have a statistically significantly lower probability of contracting corona.
But what about those who have a different blood group and still don't get sick?
Are they just lucky guys?
Not necessarily.
A team of researchers from London may have found the solution in a peculiarity of the immune system.
Coronavirus: Seronegative people have a special immune system
In earlier studies, researchers found that some people do not become infected with the coronavirus even without vaccination.
These people are called “seronegative”.
In vaccinations against the coronavirus, on the other hand, the antibodies formed have a difficult time because they are less and less compatible with the spike protein on the virus surface, which is modified by mutations.
In seronegative people, the immune system recognizes enzymes inside the virus that are important for spreading in the body and can render them harmless, thereby preventing an infection at an early stage.
Mala Maini and her research team from University College London examined 730 subjects as part of the COVIDsortium study and discovered the special role of T cells in seronegative people.
Study name: Existing polymerase-specific T cells proliferate in abortive seronegative SARS-CoV-2
Authors: Swadling et al., University College London
Release date: 11/10/2021
Seronegative people: T cells prevent viruses from reproducing
The immune system of seronegative people recognizes enzymes in the virus that "the viruses make first when they need to start multiplying," says Maini.
That is why these enzymes are also "highly conserved in evolutionary terms" and would hardly change, since they are so enormously important for the reproduction of the virus.
If the immune system then recognizes these components of the virus, it can prevent reproduction.
The so-called T-cells, which form the second protective wall of the immune system, are responsible for this.
According to the researchers, T-cells from seronegative people probably arose from a “previous infection with a similar virus”.
Experts then speak of cross-reactive T cells.
Contact with the corona virus then only leads to a "short, temporary infection, it is also called abortive", as the study says.
The disease does not break out completely, but is stopped directly by the immune system.
Immune to the coronavirus?
Some questions remain open
Despite everything, even after this study, it remains unclear why the cross-reactive T cells form in some people, for example after a cold, and not in others.
And even when a cold causes the formation of the special cells in the first place also remains unknown.
However, instead of hoping solely for the strength of one's own immune system, scientists around the world refer to the high effectiveness and protection of vaccinations, especially booster vaccinations.
