This is how previous colds affect the corona’s immune response

Coronaviruses are not unknown pathogens. So far, they come mainly from the form of harmless cold viruses. Anyone infected with them may have a better defense against SARS-CoV-2.

Four types of coronavirus already existed before Covid-19The pathogen has spread to humans. They lead to cold symptoms, which are usually harmless. Now researchers from Berlin Charity found that certain immune system cells made by people infected with these coronavirus colds increased the immune response against SARS-CoV-2 strengthen.

Auxiliary T cells also recognize SARS-CoV-2

For the study, which was published in the journal Science, nearly 800 people who had not yet been in contact with SARS-CoV-2 were recruited by mid-2020. Checks were made at regular intervals to see if they were familiar with the new Coronavirus was infected. 17 people were identified. you immune system was before and during contamination analyzed. Awareness: Your body mobilized the so-called Auxiliary T cells, formed against known coronaviruses, also against SARS-CoV-2.

Auxiliary T cells are responsible for controlling and coordinating the immune response. They ensure that other immune cells fight pathogens that enter the body directly and form customized antibodies. The so-called T helper memory cells they survive in the body for many years and ensure a rapid immune response when they come in contact with the pathogen again.

“World memory for the coronavirus”

Mobilization of these cells led to an enhanced immune response to SARS-CoV-2. For example, they identified a specific region of the characteristic peak protein in the new coronavirus, that of known Colds is similar and so fought the pathogen. Experts talk about cross-reactivity.

“In colds with more harmless coronaviruses, the immune system creates a kind of universal, protective memory for the coronavirus,” explains Dr. Claudia Giesecke-Thiel, lead author of the study. “If it comes in contact with SARS-CoV-2, such memory cells are reactivated and now also attack the new pathogen. This could contribute to a faster immune response to SARS-CoV-2, which would allow it to spread unhindered.” of Virus in the body at the onset of the infection and thus is supposed to positively affect the course of the disease “.

But the scientist also emphasizes: “This does not mean that you are definitely protected against SARS-CoV-2 if you have had colds in the past. vaccination is important in each case. “

Vaccination ensures a rapid immune response

Because: The adjuvant effect of the cross-reaction T cells the scientists also pointed to a vaccine with his vaccine Biontech post. An analysis of the immune response of 31 healthy individuals before and after vaccination showed: While normal Auxiliary T cells was activated gradually over a period of two weeks, the cross-reagents spoke Auxiliary T cells respond to the vaccine very quickly within a week. The body was able to produce antibodies very quickly and slow down the spread of the infection at an early stage.

“Even with vaccination, the body can at least partially re-enter immune memory if it has already caught a cold with endemic coronaviruses,” says Professor Dr. Andreas Thiel, also lead author of the study. “This could explain the surprisingly fast and very high protective effect we observe, at least in younger people, after a primary Covid-19 vaccination.”

Cross-immunity decreases with age

The researchers also identified another fact: Cross-immunity decreases with age. Both the number of cross-reactions T cells as well as the strength of their bond (i.e. how well they absorb the pathogen) was lower in the older participants in the study than in the younger ones. This is due to the natural changes in the aging immune system.

“The advantage that a harmless cold from the coronavirus often brings the younger ones into the fight against SARS-CoV-2 and also in boosting vaccine protection is unfortunately less in the elderly,” says Professor Thiel. This may explain why older people are more likely to get seriously ill with Covid-19 and why their vaccination protection is often weaker than younger people. “A third booster vaccine could potentially offset the weaker immune response in this most vulnerable population and provide adequate vaccine protection,” Thiels concluded.