British virus variant: more dangerous than expected

Maximilian Reindl studied chemistry and biochemistry at the LMU in Munich and has been a member of the editorial team since December 2020. He will familiarize himself with medical, scientific and health policy topics for you in order to make them understandable and comprehensible.

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The coronavirus variant B.1.1.7 is also spreading in Germany. What has long been suspected has now been confirmed by a study: The mutation is not only more contagious, it also increases the risk of serious and fatal courses. How specific is the danger?

It quickly became clear that the Sars-CoV-2 variant discovered in the south-east of Great Britain in autumn 2020 is more contagious than the original form and therefore more difficult to control. But it seemed to have little influence on the course of the disease in patients.

This assumption has now been refuted by a British study: variant B.1.1.7 is associated with a 60 percent higher risk of fatal outcome compared to the wild type.

In the meantime, the mutation is increasingly displacing the original virus in Germany as well: According to the Robert Koch Institute, around half of all new infections in this country are due to B.1.1.7 - and the trend is rising sharply.

64 percent higher mortality

Anyone who becomes infected with B.1.1.7 carries a higher risk of inpatient treatment. The Covid-19 diseases are more often severe. The mortality rate is correspondingly higher.

In the course of the study, an average of 2.5 people out of 1,000 study participants died of the original virus type - infections with the mutation, on the other hand, led to 4.1 deaths per 1,000 people examined. This corresponded to a 64 percent higher risk of a fatal outcome.

New threats to the health system

The authors of the study emphasize that the risk of a fatal course is quite low, but they emphasize that healthcare systems could quickly reach their capacity limits in view of the significantly increased rate of severe courses caused by the new virus strain.

Even a slight change in such epidemiological parameters goes hand in hand with high case numbers with greatly increased pressure on the health system - bottlenecks in intensive medical care could arise.

Can the third wave still be prevented?

Lothar Wieler, President of the Robert Koch Institute, emphasized on ZDF that Germany is already at the beginning of the third wave of infections. In fact, the current vaccination rate is still far too low to slow down a new wave. Experts are therefore predicting increasing case numbers due to the new virus variant. The easing that has taken place is likely to exacerbate this.

To what extent the newly introduced self-tests and the planned test offensive can counteract the spread of B.1.1.7 cannot be assessed at the present time.

How was it investigated?

The study examined almost 100,000 people who tested positive for the Sars-CoV-2 pathogen between October 2020 and January 2021. The researchers formed two groups of equal size: one was infected with the wild type, the other with the B.1.1.7 variant.

The participants then grouped the researchers into pairs who were as similar as possible in terms of age, gender, social status and other characteristics, but who belonged to the other infection group.

The scientists also took into account where the participants had been treated. In some regions of England, the health system was so overloaded during the study period that it may have affected mortality.

Only this comparison made it possible for the researchers to directly compare whether infections with B.1.1.7 are more dangerous than infections with the original Sars-CoV-2 pathogen.

According to the authors of the study, a further increased burden on the health system is to be expected.

Many questions remain open

The present study does not provide an explanation as to why the B.1.1.7 line is significantly more contagious and dangerous. It is also not possible to deduce from the available data whether the mutation is particularly dangerous for people with certain pre-existing conditions.

It is still unclear what conclusions can be drawn about other virus variants - such as the South African B.1.351 and the Brazilian P.1 variant. Experts suspect that these variants too - as soon as they reach Germany - will represent a significant burden for the healthcare system. Studies on this are still pending.

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