In connection with corona, corona vaccination as well as PCR tests and antigen tests, the antibody test appears again and again. But what exactly does the antibody gel mean? When does a corona antibody test make sense? Which BAU value protects against corona? This article is intended to provide a brief and quick overview of this.
Does the corona antibody test make sense?
A corona antibody test definitely makes sense after the second or third vaccination. Not, however, to determine the exact number of antibodies, but to get information about whether the vaccination has worked. Not every body can produce antibodies from every vaccine (vector vaccine, dead vaccine, mRNA vaccine), so that the protection status cannot be determined without a test.
The information whether a vaccination has worked naturally helps doctors who use higher doses or can resort to another vaccine. From this point of view, an antibody test can be recommended. It also contains further useful information: The test answers whether a corona infection has already taken place. In symptomatic cases or cases that have already tested positive, this will not be of any use, but for asymptomatic, unnoticed cases, this information can certainly be of importance.
Finally, the corona antibody test provides information about the prevailing status (at a point in time at a certain puncture site) via a parameter value – the BAU value, or long-binding antibody units per milliliter.
At what time should the antibody test be carried out?
The timing of the corona antibody test should be based on the information requested. On the one hand, the information whether the vaccine has responded and, on the other hand, the information which value currently prevails (after the vaccination or before a vaccination – depending on your preference). For this reason, the point in time cannot be generalized, but conclusions can be drawn from it. I have summarized this for you in the two paragraphs below.
Did the vaccination / vaccine work
You can tell whether a vaccine has worked after the first vaccination. This means that you should do the antibody test after the first stab, the second stab (third stab). However, it often makes more sense to carry out the antibody test before the booster to find out whether the vaccine used has worked. Otherwise, you would have to be boosted with another vaccine immediately after the booster vaccination. For this reason: After the second vaccination / before the third vaccination makes the most sense here.
How high is my current antibody level
If you want to know how high your antibody level is, you should do the antibody test for corona either shortly before the vaccination or after the vaccination. The first gives you information about the mirror about the time after the last vaccination. If the value is already low, you should boost earlier the next time. If the value is high, you can take a little more time. Before the next vaccination, you will receive a value that the mirror will tell you after a certain period of time. If you do the antibody test after the vaccination, you will get the maximum protection value. This is the maximum value that you will build up after the respective vaccination (second stitch, booster).
Strategy for Corona Antibody Tests
The best strategy for corona antibody tests is therefore after the second vaccination and before the third sting, alternatively before and after the third sting. In this way you get the maximum value on the one hand and the protection value on the other hand after a certain period of time. If the maximum value were 1500 and the value would still be 1000 after 5 months, you would have lost roughly a value of 100 per month, i.e. about 6% per month (100/1500). Note, however, that the value does not decrease linearly, but that the decrease value increases with the duration. This means that you are well protected in the beginning and worse towards the end. As a rule, the rule of thumb applies: After 4 months, the protection should only be 50% on average (maximum value 1500, after 4 months that is 750 BAU).
Which BAU antibody value protects against corona
Clear limits have not yet been published and cannot easily be determined scientifically. Every body is different and the amount of blood in the arm is different than in the nasal cavity or throat, for example, where a vaccination penetrates. Experience and approximations can help, however, and there should also be a correlation (connection) between a high antibody level and a low probability of infection.
Various articles, studies and doctors are currently trying to name these numbers, although only rough limits can be given here. Nevertheless, these limits are already informative (provisional limits, not scientifically proven):
| BAU value | statement |
|---|---|
| 0 to [20 – 25] | no immune protection / extremely low immune protection against corona given, immediate vaccination / booster vaccination recommended, vaccination could not have worked |
| [20 – 25] – [40 – 60] | Gray area, presumably poor immune protection against corona, immediate vaccination / booster vaccination recommended , Vaccination might not have worked |
| [40 – 60] – [200-300] | poor immune protection (60%), a booster vaccination is recommended |
| [200-300] – [400 – 500] | medium immune protection given (80%) |
| [400 – 500] – [900 – 1000] | high immune protection given (90%), a booster vaccination recommended in accordance with legal requirements |
| 1000 and more | very high protection against corona / full protection (95%), a refresh Vaccination can be delayed (according to legal regulations) |
Note that these limits only apply to the general public and cannot be applied to a single individual. So it can be that people with 25 BAU go through a mild infection, while people with 1000 BAU and more end up in the intensive care unit. The likelihood of this is low, but it is statistically given. The percentages are based on a confidence interval of approx. 90%, this means with a BAU of 1000 95 out of 100 people have protection, whereby this will be the case in at least 90% of the cases if it is repeated.