Omicron Variant: Experts are concerned

The never-ending story of virus variants continues: while in Europe the delta variant is responsible for the fourth wave in many countries, Great Britain and Denmark are already suffering from the omicron variant. German experts are already sounding the alarm.

The euphoria in large parts of Germany is great. Declining incidences and the fact that boosters are no longer required to be tested give hope for a relaxed Christmas season. But the next virus variant is already lurking in the form of Omicron, and the mutation has already arrived in Great Britain and Denmark. But how dangerous is the virus variant that was discovered in South Africa?

Omicron variant – how dangerous is the mutation?

Overall, little is known about the virus variant. So far, over 40 mutations have been registered in Omicron, about which the following is known:

  • Nine mutations  are found in the  N-terminal region of the spike protein , which is particularly responsible for the virus docking to human cells. The change could therefore harbor a higher risk of infection.
  • 20 other mutations  are located in the  receptor -binding domain , which is located in the spike proteins of  SARS-CoV-2  . These receptors decide which surface structure of the human cell the virus attaches to.
  • Eleven mutations  have been registered in the furin recognition region, where the spike protein is cleaved into different subunits.

According to experts, Omikron could be significantly more infectious than the previous variants. The reason for this is the changes in the spike protein, which make it easier for the virus to dock onto human cells. Another important reason is that fully vaccinated and boosted people can also contract the virus more easily.

The neutralizing antibodies of the immune system react little or not at all to the new virus variant. This means that vaccinated people infect their fellow human beings more often than was previously the case.

According to initial model calculations, the number of infections caused by the omicron variant could double every two to three days. For comparison: In this scenario, the previous Delta variant would be three to four times slower than the new mutation from South Africa.

Dirk Brockmann, head of the project group Epidemiological Modeling of Infectious Diseases at the Robert Koch Institute, has already expressed concern to the Science Media Center. According to the expert, it is important to be prepared for the highly contagious variant, since in the past in particular there was not enough reaction to mutations.

Omicron variant: booster vaccination required

The first previously published studies with various vaccine combinations show that the antibodies still have a neutralizing effect on Omicron – albeit a much weaker one. Vaccination still inhibits the entry of the virus into the cell and can thus prevent infection. Compared to the Delta variant, however, the protection is about 37 times weaker. The extent to which other parts of the  immune system  , such as B cells and T cells, fight the virus in the body has not been researched.

However, B and T cells could prevent severe courses. If the virus overcomes the first line of defense around the neutralizing antibodies, other cells are waiting to prevent the virus from spreading in the body. They recognize infected cells and can destroy them. This means that the virus can only multiply with difficulty in human cells. As a result of the corona vaccination, not only are neutralizing antibodies formed, but the T and B cells are also prepared for and recognize SARS-CoV-2.

Another, as yet unpublished analysis from South Africa indicates vaccination protection after surviving an infection plus a double vaccination with BioNTech/Pfizer. However, according to the experts, a simple basic immunization is not sufficient.

The effectiveness of the antibodies is 41 times lower than before. However, the results also indicate that a booster vaccination could continue to prevent severe courses with Omikron.

Prof. Dr. Carsten Watzl, Secretary General of the German Society for Immunology (DGfI) classifies the results to the Science Media Center:
“So far we only knew the mutations of omicron and could assume that these probably lead to a poorer protective effect of the vaccinations against an infection with the omicron variant. It is therefore important to see initial data now. The results clearly show that the neutralizing antibodies of vaccinated people are also able to bind and neutralize omicrons. So the vaccinations are not useless. But: You need significantly higher antibody levels to successfully neutralize omicron – about 40 times more.”

The expert emphasizes that the variant could be responsible for higher incidences and further breakthrough infections in the future, that booster vaccinations and variants adapted to the variant are necessary.

Moderna responds to Omicron variant

Vaccine  manufacturer Moderna  has developed several strategies to fight Omicron:

  • Increasing the third dose:  Currently 50 micrograms of the mRNA vaccine are used as a booster – 100 micrograms have also been shown to be safe in clinical studies and increase the antibody level enormously.
  • Vaccine against beta also possible at Omikron:  The current vaccines are based on the wild type of SARS-CoV-2. However, Moderna has already developed a vaccine against the beta variant of the  corona virus . Because omicron and beta share several common mutations in the virus’s spike protein, the vaccine update could also protect against omicron.
  • A vaccine against Omikron:  Moderna is already working on a booster vaccination against Omikron, but a possible vaccine would still have to be tested clinically.

How did omicron come about?

The previous thesis that the virus mutation could have originated in a   person infected with HIV is already being revised by some experts. It is well known that viruses can mutate in people with an immune deficiency – in addition to people with HIV, this also includes cancer patients and people after organ transplants. However, since South Africa is unlikely to be the origin of the virus, it could also have mutated in immunocompromised people from an industrialized country.

In addition to this assumption, the virus could also have an animal origin. Viruses can be transmitted from animals to humans and back again, changing and adapting their structure over this period.  Millions of mink were killed in Denmark last year for fear of virus mutations  .

Just like the origin of the wild type of SARS-CoV-2, only assumptions can be made about the origin of omicrons.

Worth knowing: hence the name Omikron

Since several virus variants unknown in Germany have already been named after the letters of the Greek alphabet, the next free name would have been “Ny”. In order not to confuse this with the English “new”, the World Health Organization (WHO) decided against the name.

The following letter “Xi” was also excluded. Since it is a common Chinese name and the head of government of the Republic of China, Xi Jinping, has this name, it was not wanted to have a negative connotation with the variant. The next title available was therefore Omikron.

You can read here which virus variants are still on the WHO list.

 

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