Booster vaccination against Corona: Experts warn against too short intervals

Created: 2022-01-21Updated: 2022-01-21 03:46

By: Sandra Kathe

Fourth vaccination against Corona?

© Sylvio Dittrich/imago

While the first countries have approved a fourth vaccination against Corona, experts warn that too many boosters could also overwhelm the immune system.

Berlin – In the fight against the corona virus*, politics and science are looking for an effective way to protect the population from a bad course of Covid-19 and thus end the pandemic in the long term.

An important factor here is the vaccination and the question of how often booster vaccinations make sense.

Researchers all over the world are currently working on studies that deal with the effects of various corona vaccines* and address the question of whether too frequent vaccinations can also have a negative effect on the immune system.

This is reported by the news portal DW.com.

Corona vaccination: Too frequent boosters could weaken the immune response

At the center of this question are possible effects that too frequent booster vaccinations against corona could have on the so-called T cells. T cells are part of the acquired immune response in the human body and play an important role in the defense against the disease Covid-19 caused by the coronavirus. As DW.com reports, some researchers fear that frequent contact with antigens could trigger T cell anergy and overwhelm the immune system. T-cell anergy leads to the fact that the immune response is deactivated by T-cells.

According to Harvard professor Sarah Fortune, who researches immunology and infectious diseases, there is still no evidence that repeated corona vaccinations lead to T-cell anergy - but there is scientific evidence.

That T-cells become dysfunctional when repeatedly exposed to antigens has already been "researched in HIV or cancer, where the antigen is constantly present, not just in repeated vaccinations," Fortune told DW.com.

Exhaustion of the immune system: Researchers advise greater intervals between corona vaccinations

Immunology professor Reinhard Obst from the Ludwig Maximilians University in Munich also confirmed to the news portal that T-cell anergy has not yet occurred in humans after repeated corona vaccination. Nevertheless, the expert urges caution, also for the reason that booster vaccinations in such a high frequency are not common against any disease. The thought of possible T-cell depletion should be a reason to pause.

According to Stanford immunologist Holden Maecker, numerous studies indicate that an occasional booster in the corona vaccination, analogous to the previous practice of influenza vaccination, could be the most helpful way.

He told DW.com that various studies have suggested that the immune system needs time to build up memory after a vaccination and booster shots that are given too frequently often don't show much benefit.

Fourth vaccination against Corona: EMA currently doubts the benefit of the second booster

Because in some countries, such as Israel, Denmark or Chile, it is feared that a renewed decline in antibodies in the event of a corona infection could lead to setbacks in the fight against the pandemic, up to four corona vaccinations have already been approved here.

A first preliminary study at the Sheba Medical Center near Tel Aviv has already shown that after a fourth injection no significantly increased vaccination protection against the disease could be demonstrated.

Experts from the EMA also recently questioned the great benefit of the second booster vaccination.

(ska)