The corona vaccination protection can be refreshed after six months.
Partly earlier.
Older people, for example, are advised to do so - but many hesitate.
Are antibody tests a useful decision-making aid then?
Lübeck / Berlin - The immune protection against the coronavirus is again greatly improved by a "booster" vaccination - that is clear.
Nevertheless, many people are currently asking themselves: Do I really need the third prick, or is the immune system of the previous vaccinations still sufficient?
If you ask yourself this question, you might think about an antibody test to make a decision for or against the booster.
But experts only consider this to be useful to a limited extent.
Why?
We answer important questions on this topic.
What are the benefits of a booster vaccination?
It strengthens the immune system again against the Sars-CoV-2 virus.
This is where the name booster comes from.
Actually, the term refreshment is not entirely correct, writes the immunologist Carsten Watzl on Twitter.
This makes it seem that the vaccination will restore something that has been lost.
But with the booster you not only restore the state after the second vaccination: the immunity is better after the booster than after the second vaccination.
That also makes sense, according to the expert.
Because every time the immune system comes into contact with the pathogen or vaccine, immunity becomes stronger, better and more permanent.
Should you do an antibody test before using the booster?
The ulterior motive seems sensible: Knowing how high the immune protection that has been built up by the previous corona vaccinations is.
And so you can assess whether the booster vaccination is necessary or (still) dispensable.
Antibody tests could provide clarity here, says Andreas Bobrowski, Chairman of the Professional Association of German Laboratory Doctors.
But he also makes it clear: It makes no sense to recommend these tests across the board.
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.
The Robert Koch Institute (RKI), however, has a clear message: It is not recommended to do an antibody test before the booster vaccination to check whether there is still protection against Covid-19.
One reason for this is that one does not yet know exactly from which antibody level one can assume sufficient protection.
What does the result of an antibody test tell you?
According to Andreas Bobrowski, an antibody test usually tests the so-called anti-spike antibodies (IgG) that are formed as a result of the vaccination.
It is important that such a test gives meaningful and comparable results.
This is done using a standard from the World Health Organization, which is specified in BAU / ml (BAU = Binding Antibody Units).
However, there are no safe limit values from which BAU / ml value one is still considered to be protected.
You don't (yet) know her, writes Watzl on Twitter.
Like the RKI, he answers the question of whether you have to determine the antibodies before the booster vaccination: "No."
Are there any estimates of the limit values?
Yes, that is.
Looking at data from his laboratory and from Israel, for example, Bobrowski says: Below a value of 21.8 BAU / ml, there is no measurable protection from anti-spike antibodies.
Above that, however, there is a large gray area where you don't really know when the protection is good enough.
"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." To correlate means: to be related.
Is it bad if you freshen up despite high antibody levels?
No, clarifies the RKI.
However, many people “wrongly” assume that if the antibody level in the body is high, the primary immunization should not give them a booster.
Even with immunity still in place, there are no security concerns with regard to the refreshment.
The protection only gets better.
What if the scores on the test are very low?
The discussion about these limit values is about protection against symptomatic infection, writes immunologist Watzl.
"The protection against serious illness can still be high." Therefore his advice: Do not panic if the antibody levels are low, but better arrange a booster appointment.
What does the antibody test actually cost?
These tests are usually not a cash benefit.
So you have to bear the costs yourself.
A good 20 euros are appropriate for antibody tests in which the effect of vaccinations that have already been carried out is checked.
Does a mix of vaccines make sense when boosting?
Yes, but not always to the same extent.
In Germany, only so-called mRNA vaccines are used for refreshment.
Specifically, these are the vaccines from Biontech (Comirnaty) and Moderna (Spikevax).
Anyone who received their basic immunization with one of the vector vaccines from Astrazeneca or Johnson & Johnson will receive a different type of vaccine as a booster anyway, which, according to the data available so far, gives the immune protection an enormous boost.
If the first two vaccinations were made with an mRNA vaccine, many people now ask themselves the question: Should I switch to the other manufacturer for the third prick - first Biontech and now Moderna or vice versa?
Here data from the USA, which were published as a preprint and to which the SPD health expert Karl Lauterbach pointed out on Twitter: A mixture - such as basic immunization with Biontech and refreshment with Moderna - actually brings small differences in the booster effect.
But they are just small: the effects on the antibody level in the combination Biontech / Moderna were on average at a factor of 17.3.
At Biontech / Biontech it was 14.9.
Conversely, they were 9.7 for Moderna / Biontech and 7.9 for Moderna / Moderna.
It is therefore irrelevant which mRNA vaccine you take for the refresher, says Carsten Watzl with a view to these data on request.
Especially since in this study booster vaccinations were made with the full dose of Moderna (100 micrograms).
For the refreshment in Germany, however, half the dose (50 micrograms) should be used.
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"Booster" vaccinations strengthen the existing immune protection against Covid-19.
© Robert Michael / dpa-Zentralbild / dpa-tmn
This would make the differences a little smaller or even disappear, explains the Secretary General of the German Society for Immunology.
The Standing Vaccination Commission (Stiko) recommends that for the booster vaccination the mRNA vaccine should be used, which was injected during the basic immunization.
In addition, according to the latest recommendation of the Stiko, Moderna should no longer be used for people under 30 years of age.
As the data show, nobody has to fear disadvantages in terms of the booster effect if he or she receives Biontech a third time.
For comparison: If you give mRNA vaccinated persons the vaccine from Johnson & Johnson as a booster, the antibody-enhancing effect according to this study is on average only a factor of 6.2 (when combined with Biontech) or 4.7 (when combined with Moderna).
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How much do antibody tests cost?
25 euros is still a reasonable price, but it shouldn't be much more expensive.
© Marijan Murat / dpa / dpa-tmn
On the other hand, those who received the vaccine from Johnson & Johnson for the first time benefit greatly from the mRNA booster: With Biontech the factor was 32.8, with Moderna it was even 56.1.
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Thus, these data also provide evidence of why it makes sense to boost a basic vector vaccine immunization with an mRNA vaccine.
The interval between the booster and the basic immunization was at least twelve weeks in the study.
In Germany, the Stiko usually recommends an interval of six months between the basic immunization and the booster.
Do you have to wait that long?
In theory, you can vaccinate earlier.
According to Watzl, everything between four and eight months is “probably okay” for people with a healthy immune system.
According to the recommendation of Stiko, people with a severely weakened immune system can pick up the third dose after just 28 days.
This also applies to anyone who received the Johnson & Johnson vaccine for the first time.
dpa