The corona mutants are coming – what does this mean for the vaccinations?

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The development in Germany sounds worrying: In random tests, the proportion of the more contagious British virus variant B.1.1.7 increased from just under 6 to over 22 percent within two weeks. Health Minister Jens Spahn (CDU) reckons that “the variant could soon become the dominant one for us too.” Only: What does that mean for the laborious first progress in vaccination? Do the vaccines even work against mutants? Experts give the all-clear – and give hope.

Do the current vaccines protect against new variants?

It still looks pretty good. A case in Lower Saxony, for example, where several residents of a nursing home who had already been vaccinated had positive results for B.1.1.7. were tested, was “not worrying, but shows that the vaccination works,” says the Secretary General of the German Society for Immunology, Carsten Watzl. Initially, there were no difficult courses in the home. And to prevent this is the job of vaccination. “The existing vaccines have so far protected everyone from serious illness and death,” says Giessen virologist Friedemann Weber. One can assume that with mutations the vaccination protection with regard to the symptoms will decrease somewhat and that there could be more severe courses. But: “The vaccination always protects to a certain extent.”

In general, the British variant causes “the least headache”, says Watzl, referring to relevant studies. It gets trickier with the South African mutant: Study results recently cast doubts about the effectiveness of the Astrazeneca vaccine. It therefore provides only minimal protection against light and moderate diseases. But the study is relatively small, and only younger people with generally mild progressions were included, says Watzl.

So there are no data on severe disease courses. The World Health Organization (WHO) recommends further use. In the case of the vaccine from the manufacturer Biontech / Pfizer, initial results indicated that it was also effective against key mutations in the British and South African variants. In a new laboratory study, however, researchers found significantly fewer antibodies. However, the scientists assume that the vaccine will still work.

How easily can the vaccine be adapted to new variants?

Vaccines still help at least partially against emerging variants. Should they have to be adjusted in the future, this could happen quickly, especially with the vaccines based on messenger RNA (mRNA) from Biontech, Moderna or, in the future, Curevac. “You just have to change the sequence of letters in the genetic blueprint,” says Watzl. He estimates that a change in production would be feasible in around six weeks. This is consistent with the manufacturer’s information. In his opinion, the process for vector vaccines such as that of Astrazeneca could take about twice as long. Astrazeneca recently announced a new generation of vaccines for the fall, which should better protect against variants.

In addition, there is the approval. How long the approval process takes and what specific requirements will be placed on a converted vaccine are currently being discussed at EU level. According to the Paul Ehrlich Institute responsible for vaccines and biomedical drugs in Germany, initial suggestions and ideas are being discussed there. According to Watzl, it would take roughly four to six months for the entire process to be used.

How often does the vaccination have to be refreshed in the future?

On the one hand, this depends on how quickly the effectiveness of the vaccine wears off, as Weber explains. How quickly the effect of the corona vaccines decreases and when a re-vaccination will be necessary are currently lacking long-term data.

The other unknown is whether new mutations also require new vaccines. “Coronaviruses are more sedate than other viruses,” Weber explains. However, as long as they are in circulation in large numbers, the likelihood of mutations is also higher. Overall, he could “imagine that you will have to re-vaccinate every autumn in the future”. Immunologist Watzl estimates that it “only needs to be refreshed after several years”. However, the experts agree on one point: The topic will be with us for the coming decades.

Can the body cope with several corona vaccinations in a short time?

Many people are probably not vaccinated until the summer. But what if a new mutant already needs a quick refresher in autumn? “I don’t see any problem with injecting several doses in a row,” says Watzl. The immune system can do that. The mRNA and vector vaccines do not inject a weakened virus into the body, as is the case with a yellow fever vaccination. Instead, an immune reaction against part of the coronavirus is specifically stimulated. This results in memory cells, which then provide vaccination protection, as Watzl explains.

It is important to have enough time after other vaccinations and not to set the second dose too early in a series of vaccinations. “Because then the immune reaction of the first dose would not be complete.” It is also no problem to receive the second vaccination a little later than recommended. The second dose is important in any case.

Is it possible to combine vaccines?

It is still like this in this country: Anyone who receives the first injection with Biontech vaccine will also receive the second from Biontech. But theoretically it would also be possible to inject different vaccines in one order. “It works immunologically, and it is often done,” says Weber. Watzl also suspects that this is “probably not a problem”. But as long as no studies are available, one can only stay in the subjunctive. So research is needed before such steps are seriously considered in Germany.

Will a global vaccination program help against mutations?

Several voices criticize the global vaccine distribution and warn that this could also become a problem in this country. The argument: if the virus can develop freely in some regions of the world, more mutations will occur that will eventually arrive in Germany. “The pandemic is not over when Germany is vaccinated, but when the whole world is vaccinated,” says Watzl. Weber also advocates a global vaccination program.

But both also make it clear: As soon as there has been sufficient vaccination in Germany, there is a basic immunity in the population that makes it more difficult for new variants. “If a mutant then gets through, we are no longer so unprotected,” explains Watzl. Weber also does not expect new mutations to reset progress in fighting pandemics in Germany to zero.

How many virus variants are still possible?

Since the beginning of the pandemic, Sars-CoV-2, which is considered sluggish, has already developed several potentially more contagious and dangerous variants – although there was no herd immunity and the pressure to adapt to the virus was relatively low. So does it get more dangerous with increasing immunization? “That is difficult to predict,” says Weber. It could be that only medium or half-baked immunity in the population favors the emergence of new variants. Then a lot of viruses are on the way, which makes mutations more likely. And here and there there is pressure to adapt to which the virus reacts.

When will this work with herd immunity in this country?

The most effective weapon against mutations would be the much-invoked herd immunity. You could perhaps reach them in autumn, says Weber. Until then, vaccine production will be ramped up massively. Should variants such as B.1.1.7. prevail, at least 80 percent of the population would have to be immune for herd immunity. Watzl also thinks that a largely immunized population will face the virus by autumn and that the number of infections will be depressed: “I am optimistic that we can do it.” can not vaccinate this current second wave. “

David Hutzler / dpa


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