For whom an antibody test before the booster vaccination can be useful

Düsseldorf The situation of the pandemic is coming to a head: According to the Robert Koch Institute (RKI), the seven-day incidence in Germany reached a new high of 419.7 on Thursday. For this reason, politicians are again appealing to the population to get vaccinated.

The focus is on the booster, also known as a “booster”. It should be offered to all vaccinated people in the country six months after immunization. At least that’s what Federal Health Minister Jens Spahn (CDU) wants. This is intended to refresh the immune protection and prevent so-called breakthrough infections.

However, many wonder whether their current immune protection makes a booster vaccination even necessary – and they first decide on an antibody test. Users hope that the tests will provide a statement about how high their current immune protection – as a result of recovery or vaccination – is against the coronavirus. But does that make sense? Professionals have doubts. All the facts and background information on the corona antibody test.

How is a corona antibody test carried out?

Antibodies against the coronavirus are detected in the blood. According to doctors, the most reliable form of sampling is conventional blood sampling by trained people, such as doctors. The sample is then sent to the laboratory. The results are usually available after 48 hours at the latest. There are also self-tests where the sample is taken at home. Users use a lancet to obtain blood from the fingertip, which is either placed directly on a test strip or sent to the laboratory.

Top jobs of the day

Find the best jobs now and
be notified by email.

How does a corona antibody test work?

Basically, the tests are based on the detection of so-called immunoglobulin G antibodies (IgG) against the so-called spike protein, which the virus uses to dock onto human cells. The so-called titer is determined in the laboratory by means of a blood sample; in simple terms, it is the concentration of the antibodies in the blood.

Antibody test: what do the values ​​mean?

At the beginning of the pandemic, the test manufacturers still used various measured values. The World Health Organization (WHO) has now defined the threshold value in BAU / ml as the standard. BAU stands for “binding antibody units”.

There is no official BAU limit above which a person is protected against infection with the coronavirus. You don’t (yet) know her, writes immunologist Carsten Watzl on Twitter.

However, Andreas Bobrowski, Chairman of the Professional Association of German Laboratory Doctors, gives a rough estimate of potential benchmarks. He relies on data from his laboratory and from Israel.

According to Bobrowski, there is no measurable protection by antibodies below a value of 21.8 BAU / ml. Above this, however, there is a large gray area where you don’t really know when the protection is sufficient.

“In my estimation, a value of 500 is so high that you don’t need a third vaccination immediately,” says the laboratory doctor. With anything above 1000 BAU / ml one could speak of good protection. This corresponds with what Carsten Watzl writes on Twitter after a look at the study situation on the subject: “Antibody values ​​above 1000 BAU / ml seem to correlate with very good protection against symptomatic infection.”

Should I have an antibody test before the booster?

According to Bobrowski, an antibody test can show how high your own corona immune protection is – and thus clarify whether the booster vaccination is already necessary. He distances himself from a general test recommendation. However, if you are susceptible to infections or generally immunocompromised, such a test may give you important information about how well the vaccinations have worked.

But there are no safe limit values. That is why Carsten Watzl answered the question on Twitter whether one had to determine the antibodies before the booster vaccination, also with “No”.

RKI does not consider antibody tests necessary

According to the RKI, it is not necessary to do an antibody test before the booster vaccination. The institute justifies this with the fact that it is not yet known exactly from which antibody level one can assume sufficient protection.

In addition, the institute emphasized that there were no safety concerns with regard to a booster vaccination even with a high level of immunity. It is therefore a common misconception that when the antibody level is high, no refreshment is necessary.

Antibody test useful?

Antibody tests cost between 15 and 25 euros.

(Photo: dpa)

What does an antibody test cost?

There are price differences between antibody tests that are carried out by a doctor and self-tests to be carried out at home. The prices for antibody tests at the doctor start around 15 euros. Antibody tests for at home usually cost more, with the drugstore chain DM, for example, just under 40 euros.

The prices vary according to the type of test. Qualitative tests that only show whether antibodies are present usually cost less than quantitative tests. The latter determine the exact number of antibodies and are therefore more suitable for assessing immune protection.

If you decide to have an antibody test to check your immunity, you usually have to pay for it yourself. The health insurance does not cover any costs unless the test has been ordered by the doctor.

More: Booster vaccinations against new corona infections? The most important questions and answers



Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.