Corona mutations and their dangers at a glance

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They have cryptic names and are likely to complicate pandemic containment: Corona mutations are currently worrying policymakers despite falling case numbers. What should we watch out for?

South African mutant, British viral mutation, Brazilian covid species and more: in recent weeks, modified corona pathogens have also been detected with increasing frequency in Austrian laboratories. But what does that actually mean? How widespread are they and what dangers do they pose?

Here is an overview of the most important questions and answers:

❓ Which variants are involved?
? B.1.1.7 | United Kingdom: The first sample in which the variant was detected was from September. Initial estimates said it caused 50 to 70 percent more infections compared with earlier forms. In the meantime, based on a more robust database, it can be assumed that the increase is more likely to be around 22 to 35 percent, said the Berlin Charité virologist Christian Drosten recently. Experts agree, however, that even this lower percentage could massively complicate the containment of the pandemic.

Several names for British virus variant
B.1.1.7
VUI-202012/01
VOC-202012/01

? E484K | United Kingdom: Another coronavirus variant discovered in the United Kingdom is causing concern among scientists. A report by Public Health England found that the mutation, called E484K, had emerged spontaneously in a handful of cases, the PA news agency reported Tuesday. “This suggests that the British variant is now independently developing the E484K mutation,” said Jonathan Stoye of the Francis Crick Institute. According to information from broadcaster Sky News, eleven out of 200,000 samples were affected.

? B.1.351 | South Africa: This variant was discovered in December. It is suspected that it arose because a high proportion of the population had already undergone corona infection. Drosten once explained on the NDR podcast the infection situation in townships, where people live closely together in poverty and a high proportion of them already have antibodies: “This is slowly becoming a herd immunity. That’s something where the virus has to fight antibodies if it wants to infect new people again, if it wants to set a secondary infection, for example. Against that immune pressure, a virus like that would possibly defend itself with a mutation like that.” Experts refer to this as escape mutation.

Multiple names for South African virus variant
B.1.351
501Y.V2

? “Tyrolean subtype.” According to virologist Dorothee von Laer of Med-Uni Innsbruck, Tyrol already has its own subtypes of the South African mutation that are causing concern. There is talk of “at least two fixed mutations”. It is “anything but a local outbreak,” she said. “It appears that a virus type within the South African variant has been introduced – with additional mutations. That may be pure coincidence that this virus has these mutations, but it may also be that that has some biological significance. But it doesn’t have to,” Von Laer said.

Sequencing of positive PCR samples at Med-Uni in Innsbruck is currently turning up 20 to 30 new South African mutation cases, he said. On Wednesday, for example, there had been 27 so far. Both mutation variants – i.e. the British and the South African – would account for ten to 15 percent of the total cases at Med-Uni, the South Africa mutant for about seven percent.

? B.1.1.28P.1 | discovered in Japan, coming from Brazil: Relatively few data exist on this variant. According to the RKI, it is similar to the South African one. That it is more transmissible is “considered conceivable.”

Several names for Brazilian virus variant
B.1.1.248
P.1
Intensive care physician Uwe Janssens spoke in interviews of great concern about the variant because convalescents apparently became re-infected.

? What are mutations?
▶️ In RNA viruses, the genetic material is constantly changing. “In a droplet of spit from an acutely infected person, you can probably find thousands of virus mutants that differ from each other at one or more points in the genome,” says virologist Ralf Bartenschlager from Heidelberg University Hospital. “They arise every second, in every patient.” By no means are all mutations cause for alarm.

▶️ The vast majority have no effect or are detrimental to the virus. However, some do help. For example, the original coronavirus that appeared in Wuhan has already been displaced by a variant in the early 2020s, Bartenschlager says. In a kind of race among variants, those that give the virus an advantage prevail: That could be accelerated spread or the ability to evade host antibodies.

“It is in the nature of viruses that they adapt better and better to the host,” Frankfurt virologist Martin Stürmer once told “Deutschlandfunk.” He compared the effect to a key (in a virus) that can be turned ever more smoothly in the lock (human cells).

▶️ The designations made up of letters and numbers, such as B.1.1.7 for the mutant initially discovered in Great Britain, allow experts to trace the relationships in a kind of corona family tree. Even if sometimes there is talk of “the British variant”: the exact origin is unclear. The variant was found there thanks to good surveillance.

❓ Are the new variants more dangerous?
In several countries, it was noticed, partly by chance, that new variants were in play – accompanied by massive increases in the number of cases and overburdened health systems, partly despite Corona measures. “All the variants that are currently being looked at seem to be more transmissible,” Bartenschlager says. “There is no viable evidence at the moment that any of the variants are more dangerous – in the sense of being more pathogenic or deadly.”

Because the majority of people have not yet been infected with Sars-CoV-2, the biggest concern at the moment is higher contagiousness.

A virus that escapes an existing immune response currently has no advantage globally because most people do not yet have immunity
Virologist Ralf Bartenschlager of Heidelberg University Hospital
Recently, British Prime Minister Boris Johnson had spoken of increased mortality in connection with the British mutation. However, many experts consider the data situation to be too thin.

But even if the disease itself is not more severe: By making the new virus variants more contagious, there are more intensive care patients and deaths, simply because more people are infected.

❓ Does the vaccination also work against the new variants?
? British variant: The Robert Koch Institute (RKI) wrote about this on the Internet: “There are no indications of reduced effectiveness of the vaccines so far.” Heidelberg virologist Bartenschlager also assures: “According to current data, anyone who has undergone a Corona infection or has been vaccinated has an immune response that is capable of controlling and neutralizing the British variant.”

? South African variant: In a study, vaccine producers Pfizer and BioNTech had found that vaccinated people appear to mount a somewhat weaker immune response against the variant from South Africa. The body can probably still fight back, according to Bartenschlager: “Antibodies aren’t everything, there’s also cellular immunity.” According to the president of the German Society of Virology, this immune response could weaken a second infection, making it milder. So far, he said, it appears that the immune response is better after a vaccination than after a natural infection.

This means that the new weapons are unlikely to be blunted in one fell swoop. And they can be resharpened: Moderna, the manufacturer, has announced it is developing a booster vaccine against South African variant B.1.351. Pfizer and BioNTech also believe adjustments are possible, should the need arise in the future.

? New E484K variant: In the case of the newly discovered British E484K mutation, laboratory tests showed that antibodies are less able to bind to spike proteins of the virus variant. According to virologist Alexander Kekule of the University of Halle-Wittenberg in Germany, this means that the mutation strengthens the virus against defense mechanisms in the body. “The virus escapes the immune system more easily,” Kekule said.

Those who have built up antibodies after a corona infection can contract viruses with the E484K mutation more easily than the conventional coronavirus a second time, he said. The good news, however, is that the course of the disease is usually milder. The risk of contracting the disease with E484K also exists after vaccination. However, the mRNA vaccines offer significantly better protection than a natural immune response. How much protection the vaccines would drop in E484K is not yet known, the virologist said. “Maybe the efficacy just goes down from 95 to 90 percent.” But he said he is certain that new vaccine variants will be needed by fall at the latest.

  • sources: APA, dpa, tt.com/picture:pixabay.com
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