How many antibodies are enough? Corona and the BAU value

Did the Corona vaccination work and protect? This can be easily tested by an antibody level. But which values ​​are considered high? Should the booster be considered already? When should the third or already fourth vaccination take place?

The antibody level and the antibodies formed only provide imprecise information about protection against an serious Covid illness – for example in the intensive care unit. Antibodies protect neither against infection with corona nor against transmission of the virus.

Several questions can be answered with the antibody test. On the one hand whether the vaccination worked at all and on the other hand the current level – although this number is currently not very meaningful. However, there are already initial approaches and experiences with other viruses.

Do I have enough antibodies?

A score below 22 BAU is usually considered unprotected. Here the antibody level is definitely too low to have built up sufficient protection against corona. This is followed by a gray area in which it is not defined whether the protection is sufficient. From 45 BAU a slight protection from Corona can be assumed. The higher the BAU value, the higher the probability of protection.

Even a high BAU value does not protect against infection or the transmission of the virus . However, the probability of a strong and severe Covid disease decreases with the level of the BAU value, but it cannot be ruled out.

Young people tend to have a higher BAU value than older or immunocompromised people. Younger and healthier people also maintain a higher BAU value over the longer term. So it is quite likely that children will still have a BAU value of over 1000 even after the second vaccination and a few months.

From which value does full-protection begin

The most common question is the BAU value after full protection. But this cannot be determined in this way. On the one hand, the antibodies in the blood do not circulate equally and the sources of infection (eyes, nose, mouth) are also different. Whether a BAU value of 50 is as effective as a value of 1000 cannot be confirmed. On the other hand, it has already been confirmed that the higher the BAU value, the lower the risk of serious illness. In the article Corona BAU value you will find a tabular overview of the protection in connection with the BAU value.

When are antibody tests useful?

In addition to providing information as to whether the vaccination was effective, the tests – especially in the case of unvaccinated people – can give an indication of previous infections. Even those who have recovered often have an increased interest in finding out the protective value of the past corona infection. There are two methods: the presence of antibodies (these indicate contact with the virus) and neutralization tests (tests of how well the body can hold off the virus). Since a vaccination only contains the mRNA and not the virus itself, vaccinated people without corona infections do not have any antibodies with functionality against the virus. If the infection was a long time ago, it can also happen that these antibodies are no longer available. However, antibodies (immunoglobulin G antibodies, IgG) should be present, which prevent the virus from multiplying. You can find more information about the types of antibodies (e.g. IgG, IgA, IgM) in the article about r Antibodies and immunoglobulins.

For whom are tests useful?

Antibody tests are useful for people who may not respond well to the vaccine. On the one hand, this can be a weakened immune system (due to chemotherapy, etc.), taking medication or old age. These people should consider an antibody test after vaccination to be on the safe side.

One in four has already done an antibody test and another 20% would like to do an antibody test at least in the future. For 50%, however, an antibody test is not important.

Virus and Antibody

There is no right or wrong BAU value for an individual. In addition to the antibodies (which are certainly an important factor), underlying diseases, previous illnesses, age, state of health, the vaccination dose, the properties of the current variant of the virus and many other factors are also important.

Is a booster-vaccination also useful at high antibody levels?

Many have already asked themselves whether the booster vaccination makes sense even with a high antibody level. Perhaps a comparison should be used here: How useful is it to repeat a foreign word over and over again until you have memorized it? Very useful. And so it is with vaccination. Of course you could say that you can write the foreign word 90% correctly after the second time, but there is a chance to do it better if you repeat it. The same applies to the booster vaccinations. The body is once again informed about the virus and reminded of what to do if necessary.

It is also important to mention here that many people with high antibody levels also show higher vaccination reactions. Since the body is already very well informed about the virus, it is already trying to use this information by all means, whereby the reaction is likely to be correspondingly higher.