Three new coronavirus variants. We explain whether the virus is becoming more dangerous, whether the vaccination will still help and what that means for the pandemic.
What is different about the mutated variant?
First of all: Viruses always mutate - and SARS-CoV-2 is no exception. This happens when the genome of around 30,000 individual building blocks, the nucleotides, is reproduced. Mutations are therefore primarily copying errors. Finding a mutation is therefore not surprising. By September, more than 12,000 individual mutations of the coronavirus were known, so-called point mutations. According to current estimates, SARS-CoV-2 mutates much more slowly and also less frequently than certain seasonal flu viruses such as influenza B.
In fact, most of the mutations are completely irrelevant. A substitution, for example, can be insignificant, because three consecutive nucleotides later it becomes an amino acid. However, different combinations of three bases can lead to the same amino acid. Therefore, not every accidental replacement has consequences.
The analysis of all mutations of the new coronavirus detected to date also shows that some parts of the genome mutate far more frequently than others.
Variant from Great Britain: mutations on the spike protein
So not every mutation has an impact on how the virus looks or behaves. The new virus variant, however, which was first discovered in September in England, found themselves for the coronavirus an unusually high number of mutations: 21. Four of them have no effect. This leaves 17 other mutations, nine of which are located on the spike surface protein - the spike-like protein with which the virus docks on our cells.
A mutation called N501Y is located in what is known as the receptor-binding domain. This part of the spike protein largely determines how the docking with the human cells takes place. Mutations at this point could also affect the stability of the spike proteins if they are assembled into complete viruses in the cell and then infect other cells. Differences at this point are also responsible for the fact that SARS-CoV-2 apparently spreads more easily than the old SARS coronavirus. The N501Y mutation is not new, by the way. It has appeared earlier, but the other mutations may have made it more stable.
Further mutation in variants from South Africa and Brazil
A similar mutation show also variant n, which occurred in South Africa and Brazil. In addition, researchers have found other mutations there that have a further or possibly even greater influence on the immune reactions.
The researchers are primarily focusing on a mutation called E484K, as the British Medical Journal detailed - which, according to the latest analysis, has also been found in new descendants of the variant from England. This is a so-called escape mutation. This seems to cause that the virus could escape the impact of some antibodies that the immune system has formed by using the current vaccines or after natural infection.
Specifically, this means: According to initial laboratory results, not all antibodies from people who were infected with the coronavirus earlier in the course of the pandemic or who have already been vaccinated will jump against the viruses with these mutations. We'll get to that in a moment whether the current concerns are justified and how the mutations might affect vaccinations.
Is the virus getting more dangerous?
We do not know yet. So far there have mainly been genotypic observations and laboratory tests - and even these works are mostly preprints and therefore not yet scientifically assessed. One can therefore often only speak of preliminary results and possible interpretations. The longer the period and the more data are available, the better and more accurate the result.
The greatest concern with mutations is that they have an impact on infectiousness and the course of the disease. Most mutations do not do this - and previous mutations such as the coronavirus variant D614G, which is also very common in Europe, have not led to this. However, this is assumed for the new variant from England.
Previous analyzes show: Despite the lockdown measures, the virus has spread very widely in England. While the number of cases with the old virus variant in lockdown fell, the number of cases with the new virus variant continued to rise. The researchers are therefore assuming a significantly higher transferability - now no longer up to 70 percent, but around 30 percent.
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