A lot of people are familiar with it: your partner or child has Omikron, but you stay healthy yourself. How can that be? Experts have the answer.
London – The same scenario is playing out in many German households: a family member has been infected with Corona or omicron in the office or kindergarten and is now sneezing and coughing all over the apartment. The sick person has to be quarantined, everyone else is busy doing quick or even PCR tests – and they remain negative despite mild symptoms. Although as first contact they are exposed to the virus load all day long. How can that be? Why do some people not get infected with Corona?
Corona: That's why some people don't get infected - new study results are surprising
Scientists have various explanations as to why some people do not get infected with Corona. According to studies, the following factors could influence an infection with Omikron or another corona variant:
- antibodies (T cells)
- blood group 0
Why do some people not get infected with Corona? One reason is the genes
Some researchers assume that our genes could be responsible for the fact that some people do not get infected with Corona. A British team led by Prof. Christopher Chiu is also planning further “human challenge studies” (see below). “There are people who, due to genetic characteristics, are difficult to be infected with, for example, malaria or HIV. To a certain extent, this will also apply to Sars-CoV-2," says Leif Erik Sander, head of the Infectious Diseases Clinic at the Berlin Charité German press agency. However, the genetic factors are not fully understood.
Corona: People voluntarily became infected for the controversial “Human Challenge Project”.
Researchers from Great Britain have also investigated why some people do not become infected with Corona. the You recently published the results of your study. The "Human Challenge Project" was already heavily discussed in February 2021.
Because 36 people in Great Britain had voluntarily exposed themselves to the corona virus: the scientists at Imperial College London had dripped a small amount of one of the first virus variants into the noses of the test participants. The news magazine reports The mirror. The dose was just high enough to cause an infection. At that time, many critics asked themselves the question: is it ethically and morally okay to infect people in order to be able to better protect other people?
Why don't some get infected with Corona? They have matching T cells
Fortunately, all 36 subjects aged between 18 and 30 survived the infection well. Not a matter of course, because neither were they previously vaccinated, nor had they previously been infected – except for two, who were then excluded from the test series. The remaining 34 were closely monitored medically for two weeks and then observed for a further 12 months.
The interesting thing: Only 18 test persons were infected with Corona. The other 16, almost half, remained healthy and did not develop an infection. You are among the people who do not get infected with Corona. However, many of them temporarily tested positive for low virus concentrations, as the British newspaper “Guardian” reports. So you had the virus in your body, but the PCR test didn't work. But why?
The explanation of study leader Prof. Christopher Chiu: "The virus levels did not rise high enough to trigger detectable levels of antibodies, T cells or inflammatory factors in the blood."
This is exactly what probably happens to many people who are currently certain that they have been infected by someone, sneezing and coughing a bit – but again and again negative rapid or even PCR tests to have.
Colds also have something good: under certain circumstances, they protect against an infection with Corona
But why do these people manage not to get Corona? Do they have a particularly good immune system? At least there is a high probability that they have previously come into contact with certain corona viruses, as another study shows.
Researchers from University College London examined 52 people who had had direct contact with a person infected with Covid-19. Only half of them were infected. The researchers also found T-cells in the blood samples of these test participants.
T cells, also called T lymphocytes, are white blood cells that make up part of the adaptive immune system. They work like antibody, but are less specific. This means they also react to similar viruses than those they already know.
This is important because: who before the pandemic have ever had a cold with a corona virus (these harmless corona viruses have been around for a long time), whose body now has T cells. These, in turn, can render the "bad" Covid-19 viruses harmless when they are floating around in the body.
Scientists emphasize: Vaccination is still the most effective way of protecting against corona
Incidentally, T cells remember pathogens for a long time. Anyone who has suitable T cells in their body is therefore protected for a longer period of time.
Did you often catch colds before Corona and now you feel safe? Please do not.
The private lecturer Dr. Juliane Walz, who researches T cells at the University Hospital in Tübingen, told the news magazine Der Spiegel: "It's not just about whether T cells are present or not, it also depends on the number and quality of the T cells "This means that in some people T-cells can prevent symptomatic courses, but not in others. Therefore, the scientists of all studies emphasize that one should not rely on it. The best protection against Covid-19 is still full vaccination, including a booster shot.
Corona study proves: That's why people with blood group 0 are less likely to get infected
But our genes or our blood group can also influence whether we are susceptible to corona or not. Researchers at the University of Graz found this out. The scientists have data for their study evaluated by 399 corona patients who had to be treated in hospital because of the virus.
The surprising result: blood group AB was found significantly more frequently in those infected with corona. "Our study results show that people with blood group 0 have a statistically significantly lower probability of contracting Covid-19 than people with blood group A, B or AB," explained study leader Thomas Wagner in a press release. Means: If you have blood group 0, it could be less likely that you will get infected with Corona. The emphasis is on the word "could". You shouldn't rely on that.
Corona: Why don't people get infected with omicron? Blood group 0 protects
As The mirror reports, a recent French study supports this assumption. "According to the results, people with blood group 0 could pass on the virus particularly easily, but the likelihood of them infecting others decreases." The mirror.
The data analysis showed that people with blood group A have a higher risk of corona, people with blood group 0 have a lower risk than the average population.
The goal of many of these research results is to be able to better protect people from corona in the future, also through the development of new drugs. Until then, many people will probably think: No matter how and why - the main thing is that you are healthy.
If you still get infected with Corona, you should get all the information about the prevailing Get corona variant omicron and incubation period and symptoms.
++Transparency note: This article was first published on March 10, 2022 and was supplemented with current studies on May 19, 2022.++