Immune to Corona – Do many antibodies replace a vaccination? – Politics

– Are you automatically immune to corona with many antibodies and do you not need a vaccination? The voices for determining a corresponding measured value are getting louder. However, it is still too early to determine, explains a doctor from Erlangen.

Antibodies are the gatekeepers of our immune system. They recognize the protein proteins on viruses, bind them and can prevent viruses from entering a cell and thus preventing a disease. So if you have a lot of antibodies against the corona virus in your blood, you should also be safe from infection – but it’s not that easy.

Can sufficient antibodies in the blood replace a vaccination? Not only vaccination skeptics ask themselves this question after an infection. There are also recommendations in science, but no uniform consensus on how long the recovered status can last and when vaccination is necessary after recovery.

Virologist Prof. Hendrik Streeck, who is also a member of the Federal Government’s Corona Expert Commission, told the Augsburger Allgemeine Zeitung provided food for thought in this debate. According to Streeck, a high antibody value can serve as proof of immunity “for pragmatic reasons”.

Which antibodies really help?

The only question is: Where is this value? Some doctors assume 1000 antibodies per milliliter of blood. An assumption that Prof. Hans-Martin Jäck, immunologist at the Friedrich-Alexander-University Erlangen, would never subscribe to. Because not all antibodies can also prevent infection with the virus. “Only some antibodies prevent a virus from penetrating the cell, so-called neutralizing antibodies. The others only bind the virus, but do not prevent penetration,” explains Jäck.

This means that anyone who has a high proportion of antibodies against the coronavirus does not automatically have many of these neutralizing antibodies. Hendrik Streeck also pointed out that you can still contract corona, even if you have a high titer (editor’s note: high antibody value).

Elaborate and expensive tests required

There are already rapid antibody tests that can prove whether the test person has already come into contact with the virus or has received a vaccination. However, these do not determine the crucial value of these neutralizing antibodies, which prevent infection. “If I want to know whether and how many antibodies I have that actively protect against the virus, complex and expensive tests are required in the laboratory. It is impossible to carry out these with such a large population,” says Hans-Martin Jäck.

Extensive studies are still required to determine a general antibody value at which an illness with corona is as unlikely as possible, as suggested by Streeck and other physicians. In the ideal case, tests with thousands of vaccinated test persons, Jäck recommends: “Probabilities get better and better the more test persons are tested. The more tests, the more precisely this value can be determined.”

But even if this value is determined at some point, i.e. from how many antibodies it can be assumed that the person could also have sufficient neutralizing antibodies in the blood, it is only a matter of probability. Although there are already first study results from the USA, France or England, reports Jäck. But according to the current status, a debate or the precise determination of such a value is still very premature.

That’s why the recommendation of the Erlangen immunologist is at the current time: “Be sure to get vaccinated at the intervals recommended by the permanent vaccination committee.” He also refers to the fourth vaccination for people with previous illnesses and waiting for Omikron-adapted vaccines is also not recommended. Because it is clear that those who have no antibodies at all are less protected against the virus.

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