The coronavirus is mutating. Mutations are not uncommon. However, some coronavirus variants are spreading rapidly. Does a vaccination still help? An overview.
Berlin – Corona mutants are reported from all parts of the world. The names are confusing: B.1.1.7, B.1.351 and P.1. The British corona mutation B.1.1.7 dominates in Germany. According to the Robert Koch Institute (RKI), the proportion of the variant is now more than 80 percent. The wild type Sars-CoV-2 is being pushed back further. Experts are alarmed. But what does that mean? Do vaccinations sometimes work worse?
Corona mutations: how does it come about?
Viruses are constantly mutating – Sars-CoV-2 is no exception. Viruses smuggle their genetic information into cells in order to survive. Once in the cell, they do what they do best: multiply. Errors can creep in when the genetic material is copied during virus replication. These can give the virus an advantage, for example to spread faster. Others, however, go unnoticed.
Scientists examine the selective changes – mutations – in the genetic make-up of the pathogen. “Coronaviruses make comparatively few mistakes during their reproduction, much less than, for example, the HI virus,” says Albrecht von Brunn, an expert on coronaviruses at the Max von Pettenkofer Institute of the University of Munich Süddeutsche Zeitung.
Which corona mutations are dangerous?
Nonetheless, coronavirus variants with an unusually high number of mutations have come into focus. There are the “worrisome virus variants” (Variants of Concern – VOC for short) – these include B.1.1.7, B.1.351 and P.1. They were found in Great Britain (B.1.1.7), South Africa (B.1.351) and Brazil (P.1).
These VOCs have mutations that have an impact on the transferability, virulence or are relevant to the immune response of convalescent or vaccinated people, reports the RKI. Especially the mutation called N051Y.
British corona mutation B.1.1.7
The corona mutation B.1.1.7 was first discovered in Great Britain in September 2020 and spread there rapidly. That is why it is often referred to as the British variant. B.1.1.7 shows several mutations, including a change in the spike protein – the prickly protein with which the virus docks to our cells.
This change, also known as N501Y, makes it easier for the virus to attach to and infect human cells. The coronavirus variant B.1.1.7 is many times more contagious than the original wild type of the virus. Assumptions that B.1.1.7 could lead to more fatal Covid-19 courses were initially not confirmed. In a current University College London study Researchers were unable to determine any higher mortality among those infected with B.1.1.7.
The vaccines previously approved in Germany seem to protect. So far, there is no evidence of a substantially reduced effectiveness, shares that RKI with (as of April 16, 2021).
Special form B.1.1.7 E48K
There is a special form of this virus variant B.1.1.7 with an additional mutation (called E484K) – i.e.: B.1.1.7 E484K. It has been proven several times in Great Britain, but is still considered rare according to the RKI. The mutation called E484K has an additional change in the spike protein. It also occurs in the variants P.1 and B.1.351, which are common in Brazil and South Africa (see below). This is a so-called escape mutation (in German: flight mutation). It appears to protect the virus from the antibodies people make after infection or from a vaccine against Sars-CoV-2. It outwits the existing immune defense system.
In Germany, the special form B.1.1.7 E484K hardly occurs. According to the RKI, only 43 cases were discovered in 40,000 samples in which the British corona mutation B.1.1.7 was last detected (RKI report on virus variants of Sars-CoV-2 from April 14, 2021).
|Coronavirus variant||Presumed property||Influence on Covid-19 vaccines|
|British variant B.1.1.7.||Increased portability||So far only minor to moderate effects on the effectiveness of the vaccines. This applies to both the vector-based vaccine Vaxzevria (AstraZeneca) and the mRNA vaccines Comirnaty (BioNTech / Pfizer) and the COVID-19 Vaccine Moderna.|
|South Africa variant B.1.351||Increased transferability, evidence of contagion||Presumably reduced effectiveness of the immune response after infection / vaccination|
|Brazil (Manaus) variant P.1||Indication of possible re-infection, presumably increased transferability||Indication of a slightly lower clinical effectiveness of the vaccines. Covid 19 disease despite vaccination – but overall protective effect against a severe course|
South African variant B.1.351
Virus variant B.1.351 was found in South Africa at the end of 2020. This variant has several mutations in the spike protein – and also mutations such as E484K. It appears to be more contagious than the basic form of the virus.
Several studies also indicate that the South African variant B.1.351 has the ability to weaken the effects of antibodies from people who were infected with the original variant. People who were already infected with Corona fall ill again. Vaccines also appear to be less effective at protecting against the modified virus.
In Germany, B.1.351 has been spreading for weeks, but at a stable low level. According to the RKI, 646 cases have been detected so far. This corona variation has shown a constant share of around 1 percent in the last few weeks (as of April 14, 2021).
Brazilian variant P.1
The P.1 variant was detected for the first time in the Brazilian state of Amazonas in the city of Manaus. It is similar in its changes to the South African variant (B.1.351). P.1 has mutations like E484K. According to the RKI, experimental data indicate a reduced effectiveness of neutralizing antibodies in recovered and vaccinated persons for this variant as well. Increased transferability is therefore also considered conceivable. According to the estimates of scientists, the type B.1.351 detected in South Africa could “represent a basis for the development of so-called immune escape variants”.
Corona variant P.1 shows a share of 0.1 percent from all surveys in Germany (as of April 14, 2021).
South African variant B.1.351 and Brazilian variant P.1: This is how the corona vaccine works
Corona vaccinations help a bit, even if they cannot protect against infection with variants B.1.351 and P.1. Doctors assume that the vaccination can at least prevent severe Covid 19 disease courses. The vaccine manufacturers have so far assumed that the efficacy of their preparations will be at least slightly limited in the widespread British, Brazilian and South African variants.
Nevertheless, there is an extreme scenario: What happens if the coronavirus mutates in such a way that neither vaccines nor a survived infection protect. An escape mutation prevails. Does everything then start all over again?
According to researchers, such a horror scenario is possible. But the current vaccines can be adapted to the future mutations. This could happen quickly, especially with the mRNA vaccines from Biontech, Moderna and, in the future, from Curevac as well.
“You just have to change the sequence of letters in the genetic blueprint,” said the Secretary General of the German Society for Immunology, Carsten Watzl, of the dpa news agency. A changeover in production would probably be feasible in around six weeks. The approval of corona vaccines against variants should then also go faster. Manufacturers of already approved corona vaccines should in future have to submit fewer data to the European Medicines Agency (EMA), the European Parliament’s Health Committee agreed on April 16, 2021. (ml) * Merkur.de is an offer from IPPEN.MEDIA
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