After the corona vaccination, many want to find out whether it also worked for them. They can have their antibody levels checked for this. Laboratory doctor boss Andreas Bobrowski says in the FOCUS Online interview when the value is high enough – and when a third vaccination makes sense.
The ever-increasing discussion about third-party vaccinations makes some vaccinated people doubt their immune protection. They are wondering whether the vaccination has built up a sufficient level of antibodies in them to actually be protected against severe Covid disease. Those who have recovered often ask themselves this question.
In order to determine their own immune protection, many have their antibody levels checked – for example with Andreas Bobrowski. The Lübeck doctor for laboratory medicine and chairman of the board of the professional association of German laboratory doctors has carried out corresponding tests very frequently in recent months. “In most cases, vaccinated people want to know whether the vaccination worked for them,” he says.
Unfortunately, clear limits as to the value at which the antibodies protect against infection or disease have not yet been officially defined. But there are now first approaches – “and experience with other viruses can also help here,” explains the head of the laboratory doctor.
Is the antibody level
“Everything between 21.8 and 44 is still in a gray area,” admits the doctor. “We don’t know exactly how big this area really is. In general, we can assume that a person with a BAU value of over 1000 has full protection. However, we cannot say at the moment whether this is not the case at 30 or 40.”
However, the doctor generally advises patients with a value of over 1000 against a third vaccination: “Your antibody titer is high enough.”
The concentration of antibodies in the blood is usually given in the unit BAU, short for Binding Antibody Units. “In this way, the values can be compared worldwide because they are based on a standard serum from the WHO by converting them into this unit,” explains the laboratory doctor. “That’s where the somewhat odd value of 21.8 comes from.”
Andreas Bobrowski is a specialist in laboratory medicine and first chairman of the professional association of German laboratory doctors.
Again and again there are patients who have a very low antibody level, i.e. a value below 21.8, despite a Covid disease or vaccination. “Here it is likely that the vaccination did not work,” explains Bobrowski.
There could be various reasons for this. In addition to errors in the administration of the vaccine, the lack of an immune response is often due to an immune deficiency in the patient. This often occurs in very old people, for example, as well as in cancer patients who are undergoing chemotherapy or those who are taking immunosuppressive drugs.
“We have to make a distinction here when we are thinking about a booster vaccination,” explains Bobrowski. “In general, I would say: If the BAU value is below 21.8, a third vaccination makes sense.” This applies in any case to all patients who are otherwise healthy. “If, on the other hand, a patient takes medication that suppresses an immune reaction, or if he receives chemotherapy, even a third vaccination cannot lead to a sufficient titer.”
However, according to the laboratory physician, these patients should still receive another vaccination. Because the vaccination could not only provoke antibodies, but also cellular immunity through activated T lymphocytes, which also represents protection against Covid-19, according to Bobrowski.
The corona vaccines currently approved in Germany are based on two processes: messenger RNA (mRNA) or a vector. FOCUS Online has illustrated how these approaches differ in an animation series.
