Corona variant: whta you need to know about Omicron so far

Corona variant whta you need to know about Omicron so far

The new Corona variant Omicron concerns science and politics. But how contagious is the mutant? How severe is the course of the disease when infected? Will it displace Delta? What we know so far - an overview.

The Omicron variant of the SARS-CoV-2 coronavirus discovered in South Africa has also been detected several times in Germany. Some politicians and researchers fear that B.1.1.529 could be even more contagious than the highly infectious Delta variant. An overview of the first findings and countermeasures.

The World Health Organization (WHO) classified the global risk from the newly discovered corona variant "Omicron " (B.1.1.529) as "very high" on Monday. Last Thursday, the new variant was discovered in South Africa.

Omicron has apparently been around in Western Europe longer than previously assumed. This is indicated by a message from the Dutch health institute RIVM, according to which two local infections with the mutant had been discovered that were eleven days ago (as of November 30, 2021).

Four suspected cases have already been confirmed in Bavaria. There is one confirmed case each in Hesse and North Rhine-Westphalia. There is also an infected person in Saxony. A suspected case that has not yet been confirmed occurred in Lower Saxony.

Is Omicron more contagious than the predominant Delta variant?

It is not yet clear how contagious B.1.1.529 is. The virus variant has mutations near what is known as the furin cleavage site, a region that plays a role in the uptake of the virus by human cells. An improved transferability through these changes is conceivable, explains the Berlin virologist Christian Drosten. It has not yet been proven with certainty. The numbers in South Africa alone do not necessarily indicate increased transferability, among other things because the number of infections there has recently been greatly reduced and newly emerging outbreaks could appear oversized against such a very small background.

In the meantime, however, the international suspected cases and evidence are increasing - although the search for Omicron has mostly only been carried out specifically since Friday. The variant could therefore have spread far more widely than previously known. A case in Hong Kong can be seen as an indication of higher transferability: There a man was in quarantine in a hotel room after his entry from South Africa, but apparently did not have an adequate face mask on when he took his meal order. This may be the reason for the infection in a hotel guest in the room across the street.

How contagious is B.1.1.529 (omicron)?

Some of the mutations in the new variant are known, such as the N501Y mutation. It means that the virus can spread faster. According to initial findings, South African scientists assume an increased transferability of Omicron . The daily infection rate in South Africa had almost doubled recently. Some local researchers attribute this to the new variant, but the country's National Institute for Communicable Diseases does not.

There are also several indications for the modeler Viola Priesemann that Omicron is significantly more contagious than the delta variant of the coronavirus. The number of cases in South Africa was therefore very low, but then rose surprisingly quickly in a short time. A chance outbreak is not very likely: "What we see indicates a stronger infection," said Priesemann in the Dlf. She also referred to a case in Hong Kong, where a person infected with the new variant in a quarantine hotel infected another person in a room across the street, "possibly purely through the hallway and air exchange".

Do the approved vaccines work against B.1.1.529 (Omicron)?

The Mainz vaccine developer Biontech has started developing a vaccine against the Omicron variant of the coronavirus. This is part of the standard procedure for new variants, the company announced on Monday: "The first steps in development overlap with the necessary tests to determine whether a new vaccine is even necessary." It is currently unclear whether the current corona vaccines also protect against the new variant.

The results of the first laboratory tests are expected in around two weeks. In any case, the genetic properties make some experts worry about vaccination protection: Omicron has mutations in several crucial places. "An adaptation of the vaccines to Omicron is certainly possible, if necessary," says the virologist Oliver Keppler from the Max von Pettenkofer Institute in Munich. He estimates that this could take four to six months.

Corona expert Drosten currently assumes that the available vaccines "continue to protect" in principle. Protection against serious illnesses is particularly robust against virus changes. According to RKI President Lothar Wieler, vaccination is still the best option, even if its effectiveness may be reduced. Anyone who has been vaccinated has a certain protection. For a complete failure of immune protection, according to scientific knowledge, "significantly more mutations" would be required in the spike protein, according to Drosten.

According to the Berlin infection immunologist Leif Erik Sander, Omicron has many changes in places where the best antibodies can bind. But the human body forms an enormous number of different antibodies and also special cells of the immune defense, which usually recognize completely different places than the antibodies.

Why do viruses mutate?

When viruses multiply, mutations occur, copying errors in the genome, so to speak. If these give the virus an advantage, for example if they help it to spread faster, the copying error will also reproduce and under certain circumstances will prevail as dominant. B.1.1.529 shows a particularly high number of mutations. One explanation for this is that they could have originated in a single person in whom the virus was able to survive for a long period of time, for example in a patient with a weakened immune system.

Why is the international concern so great?

According to the virologist Keppler from the Max von Pettenkofer Institute in Munich, the Omicron variant is highly contagious and is currently displacing the Delta variant in South Africa. There is concern that the current vaccines might protect less well against Omicron than against the previous variants, according to Keppler. Laboratory tests over the next two weeks will show whether the vaccination protection is impaired and how much. The vaccination certainly gives partial protection.

Omicron carries more mutations than any other variant known before, more than 30 of them in the spike protein, through which the virus docks to human cells. The body forms antibodies against the spike protein when it becomes infected with the virus. Many of the vaccines also stimulate the immune system to produce antibodies against this protein. In addition, there are - besides others with unknown possible consequences - the mutations near the already mentioned Furin Cleavage Site.