– The incidence values in Germany are higher than ever. By now, everyone should know someone who has been infected with the corona virus sooner or later. Although Covid-19 is spreading rapidly, there are still people who have been spared the disease. There are various possible explanations for the phenomenon.
Over 21 million people in Germany have now been proven to be infected with the corona virus. There are more every day. Some people are even struck by the disease for the second or third time. But there are still a few who have not yet been infected. Why is that?
The Korean doctor Ma Sang-hyuk tries to explain the phenomenon in a simple way: “The adults who have not yet been infected with Covid-19 have interpersonal problems,” the expert wrote on Facebook, according to Korean media reports. However, the post has been deleted. Sang-hyuk later substantiated his statement to the Korean portal NewDaily that he only meant it “metaphorically”. He wanted to emphasize how difficult it is to avoid the virus when the number of infections in a region is high.
Because it’s not quite as simple as Ma Sang-hyuk’s explanation. The contact behavior of people is a decisive factor in the spread of the virus, as the last lockdowns have shown. But people who live with infected family members and sometimes even shared a bed with them also remained negative.
Corona test is negative despite contact with infected people: These could be the reasons
One thesis of scientists refers to genetics. A person’s genetic make-up can affect how easily someone becomes infected. Crucial to this are the ACE-2 receptors, which the virus uses to enter host cells and multiply. Since everyone has a different height, width or depth in their gene, the virus fits the receptor better in one person than in others, explains Carsten Watzl, head of the immunology research department at the Leibnitz Institute for Labor Research at the TU Dortmund World. This means that some people are more easily infected than others because the virus can dock with them particularly well.
Not infected with Corona – the influence of the blood group
Another possible indicator, according to French researchers, is a person’s blood type. Accordingly, Sars-CoV-2 was most commonly transmitted between couples when the blood groups of the partners were compatible – i.e. when they matched each other in a blood transfusion.
According to the study, people with blood group zero have the lowest risk of infection. But the best thing you can do is pass the virus on. Therefore, people with this blood type are often referred to as super spreaders. People with blood group AB have the highest risk of infection. In absolute numbers, most people in this country became infected with blood group A. However, this is also the most widespread in Germany, which distorts the statistics somewhat.
Another factor related to the risk of infection is the immune system: the body’s defense system consists of an innate part and an acquired part. The latter is capable of learning and adapts again and again. Since the corona virus is not a completely new disease, since corona viruses were discovered as early as the 1960s, it could be that some immune systems have already come into contact with similar pathogens and therefore do not infect people so easily.
Partial immunity against corona because of T cells
There is also a so-called partial immunity against the virus. This was discovered by researchers at the renowned Carolinian Institute in Stockholm. The reason for the partial immunity are the T-cells. They are part of the body’s defenses and recognize cells that a pathogen has invaded and destroy them. “There are T cells that are probably relics of previous infections with corona viruses. They are able to see a Sars-CoV-2 or fragments of it,” explains Professor Watzl world. T-cell immunity can also exist in people with a mild course of corona or in infected people without symptoms – even if no antibodies are detected. In addition to the “interpersonal contacts” factor, there are several medical explanations as to why some people do not become infected with the corona virus.