Effectiveness of the vaccination: tests on immune protection are controversial

It is a Race: Will Germans be vaccinated fast enough to stop the spread of the delta variant – or at least mitigate its worst effects? Almost 60 percent of Germans have been vaccinated at least once. The scientific community is already debating when to repeat a Booster vaccinations could be necessary. It is still unclear who will need the third vaccination with Biontech, Moderna or Astrazeneca.

Whether a vaccination works as desired can be determined by special Antibody tests recognize. Laboratory physicians and diagnosticians plead for the tests to be used in large numbers. But the Standing Commission on Vaccination (Stiko) disagrees. For whom the examination of the own immune response is thus meaningful?

Here's how the test for vaccine protection works

As Immune response physicians refer to the body's reaction to the vaccine as the. The more antibodies the immune system forms after vaccination, the lower the probability of contracting Corona – and thus the better the immune response. Quite independently of the vaccine injected, however, age and Pre-existing conditions Influence the immune response.

A weak immune system, for example of people with cancer, may form fewer antibodies after vaccination. "The individual response to vaccination can be very different," says Dr. Christine Falk, President of the German Society for Immunology.

Immune protection: These values are decisive

To determine the individual Immune protection To find out the cause of the disease, physicians can rely on neutralizing antibodies Antibody tests that are formed during vaccination. These antibodies block the docking sites of the spike protein of the coronavirus. The virus enters cells through these docking sites. So you can think of vaccination "as sticking chewing gum on a key so it won't fit in the lock and become useless," says Falk.

When will the Corona vaccine booster come??

Effectiveness of the vaccination: tests on immune protection are controversial

To determine how badly the "key" is stuck, a blood sample is tested to see if it contains spike-specific antibodies. Diagnosticians have set the relative value of "AU/ml" for this in the most common tests.

If the value is below 50, no antibody against the Spike protein verifiable. "If the value is between 50 and approx. 1000, the vaccine protection is rather low," says Falk. A good immune response is present at a level of 1000 AU/ml or above. Overall, the scale goes up to 40.000 AU/ml.

Laboratory physicians call for expansion of antibody tests

So it's easy to tell from this scale when a booster shot is needed? The professional association of German laboratory physicians is already calling for more antibody testing to detect neutralizing antibodies. In Austria, these tests are already being used as part of the national testing strategy to do just that. The Association of the Diagnostics Industry (VDGH) advocates that Germany should also go down this path.

In this country, the testing strategy is still designed to Infection as quickly and easily as possible in order to prevent their spread. Therefore, antibody tests are also performed only when corona symptoms appear. Then there is a clinical indication, i.e. a medical necessity for it. Without it, those willing to test the costs itself take over, so the technician health insurance company on inquiry.

Means: Those who want to check their own immune response by means of an antibody test as a precautionary measure have to pay themselves. VDGH argues: If more people could take this test, then more people would have Trust in the effect of the vaccination.

Meaningfulness of vaccination tests: Stiko disagrees

Dr. Christian Bodgan, Member of the Stiko, contradicts: "To propagate a testing of all Covid-19 vaccinated people without any reason is not target-oriented and gives the impression of a business model."The Stiko rejects so far a general examination of the immune response by an antibody test. "After all, we do not routinely monitor vaccination success using antibody levels, even for vaccinations against other diseases," Bodgan says. Especially since not only the antibodies of the vaccination would contribute to the protection against Corona.

Several studies show that even T cells can recognize and destroy cells affected by corona. "To answer the question of when booster vaccinations are needed after basic Covid 19 immunization, the primary relevance is whether and when increased Breakthrough infections and -illnesses are observed," says Bodgan.

In the case of a breakthrough infection, a person becomes infected with the coronavirus despite having survived covid disease or having been fully vaccinated. According to Bogdan, there is not enough data yet.

Vaccination protection is already checked in old people's homes

"Area-wide testing for the strength of the immune response cannot be done," also says Christine Falk. However, especially for risk groups such as patients with oncological diseases, autoimmune diseases or transplants, the tests would be very useful.

Because of the attacked or deliberately suppressed immune system these patients often show a weak immune response to the vaccination.

Falk is among the group with a possibly weak immune response moreover People over 80. "Many homes have already started measuring to find out for whom a booster vaccination will be necessary." Outside the homes, the situation remains unclear. Tests for infections will probably remain the rule for the time being – tests for vaccination protection the exception.