Is mutation an evolution or a disease

Coronavirus Mutations - What we know about it so far

Three corona mutations are currently dangerous

There are now three corona mutations that could be particularly critical. The most recently discovered is a Brazilian virus version B.1.1.248 or P1, which has also been appearing increasingly in Japan since the beginning of January. Then the variant B.1.351 or 501Y.V2 identified in South Africa and its British cousin B 1.1.7.

According to the current state of knowledge, all three mutants are significantly more contagious than the original virus. Researchers estimate that the risk of infection has increased by 50 to 75 percent.

Because all three new virus variants have the mutation N501Y: It leads to changed proteins - in the so-called spike proteins. The scientists hypothesized that this makes it easier for the virus to dock onto human cells.

But this single mutation cannot alone explain why the new variants may be more contagious. Because the N501Y mutation appeared several times in the past year, but then disappeared again. Experts like Richard Neher from the University of Basel assume that it is only the combination of different mutations that gives the virus an advantage.

Suspicion: The South African and Brazilian variants are trying to escape the immune system

The South African and Brazilian variants carry another mutation in their genome, called E484K. It seems to weaken the human immune defense.

Initial studies show that the E484 mutation could help the virus to partially escape the protective effects of antibodies against SARS-CoV-2 that have already been formed: This is known as the immune escape mutation. Because of this mutation at one point in the spike protein, some antibodies seem to no longer bind and to be able to neutralize the virus. This means that the virus at least partially escapes the immune response.

There is also now evidence that the Brazilian and South African variants infect people who have already contracted Covid.

What does the emergence of highly contagious mutants mean for us?

First of all, the course of the Covid-19 disease is no more severe than that of the conventional corona virus. But because the mutants are more contagious, far more people could die than from a virus that causes a worse disease but infects far fewer people.

That is why experts like epidemiologist Adam Kucharski, mathematician at the London School of Hygiene and Tropical Medicine, speak of the fact that we are dealing with a new pandemic.

Chief virologist Christian Drosten from the Berlin Charité warns:

How do mutations arise?

In order for viruses to multiply, they have to copy their genetic make-up. And mistakes keep coming back. You can think of a mutation as a kind of typo. Most errors go unnoticed, but a few can also lead to the pathogen acquiring new properties. And if this new property means that the virus can reproduce better or escape the host's immune system, then that is a competitive advantage.

So far, the corona virus has mutated relatively slowly. On average, two mutations per month were noticed. The new virus variants are characterized by the fact that they have collected many mutations in a relatively short period of time - at least 17 of them. Virologists speak of an evolutionary leap.

How did these successful coronavirus mutations come about?

As long as any virus can find a susceptible host anywhere to infect, there is no urge to change. However, if it becomes more difficult to find enough people because many have already gone through the infection and formed antibodies, then the virus has to find a new path. A mutation that makes the virus more difficult to recognize by the immune system has an advantage. So it can assert itself well.

Many virologists believe that such mutations have appeared where a large part of the population has now gone through the corona infection - namely in the Eastern Cape in South Africa and in Manaus in Brazil. Because if the population is immune to the conventional virus, it has to change in order to survive.

Some experts also fear that similar mutants could have matured in other places. And in countries that have not got the pandemic under control for a long time, such as in the USA, Russia, but also in Spain or Italy.

The virus has another possibility of adapting well to the host through mutations if it can stay in a patient's body for a long time and multiply. For example, when the immune system is very weak as a result of chemotherapy or radiation therapy. The virus then has time to test all the tricks.

Can there be more mutations if we are vaccinated?

Possibly yes. Experts like Edward Holmes, evolutionary biologist and virologist at the University of Sydney assume that as immunity increases in the population, the virus will also try to find loopholes more and more. Because it is becoming increasingly difficult for the virus to find a susceptible host because too many people are immune to SARS-CoV-2.

Presumably, the virus will also change in such a way that the infections are more seasonal. Because when there are fewer and fewer susceptible people in the population, the optimal conditions for spreading become more important. That's why the vaccines will be adapted to this at some point.

How do the known vaccines against mutants work?

According to all that is known so far, the vaccines are at least also effective against virus variant B.1.1.7. from the UK. And this even though the mRNA vaccinations from Pfizer / BioNTech and Moderna precisely target the prickly protein, which is also affected by some mutations such as the N501 mutation.

Biontech's vaccine has so far only been tested for a few changes in the mutations

A study published in preprint by the pharmaceutical company Pfizer and the University of Texas comes to the conclusion that the vaccine from BioNTech / Pfizer is also effective against the N501 mutant. The researchers worked with blood samples from 20 people who had been vaccinated. In vitro, their antibodies also neutralized 16 different virus mutations.

The most recent evaluation of this Pfizer / Texas study in preprint shows, however, that the complete list of mutations that characterize the new variants b.1.1.7 and B.1.351 has not been examined. But two combinations of three mutations each. It would be important to analyze the entire combination of genetic changes that characterize the two variants from South Africa and Great Britain.

The moderna vaccine was examined in more detail for its effect against mutations

For this purpose, Moderna, together with the National Institutes of Health of the USA, has produced three SARS-CoV-2 viruses that completely contain the mutations that were discovered in the variants South Africa B.1.351 and in Great Britain B.1.1.7, i.e. all 17 Mutations that characterize both variants. So far, this is the only official study in which all mutations are analyzed at the same time. However, it only appeared in preprint. The viruses were mixed with human blood serum to see whether the antibodies that formed were able to fight the mutations. The Monderna vaccine succeeded in doing this with both variants. However, the concentration of neutralizing antibodies was significantly reduced in the South African variant, i.e. this variant of the virus could escape vaccines.

Why vaccines presumably also protect against mutations in the virus of origin

Even if a mutation affects the effectiveness of the vaccine, it does not immediately render it unusable. The vaccines approved to date induce so-called polyclonal antibodies that attach to different parts of the virus. If the virus changes in one of these places, this may weaken the effect of the vaccine, but it does not make it completely ineffective.

In addition, a vaccination also provokes an immune response at the cellular level, which ensures that already infected human cells are killed.

Are manufacturers already developing their vaccines to prevent problems caused by mutants?

The Mainz-based company Biontech said: "We are continuing to investigate the protective effect of the COVID-19 vaccine against these new virus variants."

In addition, the managing director of Biontech, Uğur Şahin, repeatedly assured that the mRNA vaccines could be quickly adapted to new variants. He said:

Both Biontech / Pfizer and the US vaccine manufacturer Moderna work with a so-called platform strategy. This means that you can quickly set up new vaccination models on the existing platforms of mRNA technology. This means that the vaccines can be adapted comparatively quickly in the event of a virus mutation.

Astrazeneca vaccine shows limited effectiveness in virus mutation from South Africa

Current studies suggest that the corona vaccine developed by AstraZeneca against the mutation of the coronavirus from South Africa is likely to have only a very limited effect. The preliminary study data from the Universities of Oxford and Witwatersrand should show that the vaccine in variant B.1.351 is still effective against severe courses, but prevents minor diseases to a lesser extent. The question, however, is how meaningful the data is. The majority of the 2,000 subjects in the study were young and healthy.

South Africa, which has been particularly badly affected by the corona pandemic, has now postponed its vaccination campaign with the AstraZeneca vaccine until further information is available about the vaccine's effectiveness in the case of mutations.

How do you find mutations?

By examining the genome of the virus closely, mutations can be found. Positive corona test samples are subjected to so-called genome sequencing. This analysis method examines the blueprint of the virus in detail and can thus detect changes in this blueprint.

Only a few laboratories nationwide can do this. Estimates assume a low double-digit number. The Association of Accredited Laboratories in Medicine is currently inquiring about the numbers. In order to sequence the genetic material of the viruses, not only special sequencing machines are required, but also well-equipped bio-informatics in order to evaluate the construction plans of the virus. Federal Minister of Health Jens Spahn wants to promote sequencing in Germany more strongly and has stipulated that every regional laboratory should send five to ten percent of its positive samples to these sequencing laboratories. These laboratories in turn pass the data on to the Robert Koch Institute. One hopes to discover which mutants of the virus are already circulating in our country.