▷ Information from the Bundeswehr Institute for Microbiology (IMB) on the new …

29.11.2021 – 14:10

Press and information center of the Bundeswehr medical service

Koblenz (ots)

Information from the Bundeswehr Institute for Microbiology (IMB) on the new Omikron variant (B.1.1.529)

Oberstarzt Prof. Dr. Roman Wölfel

Chief Veterinarian Dr. Katharina Müller

Chief Veterinarian Dr. Rosina Ehmann

Like all viruses, SARS-CoV-2 changes over time due to mutations in its genetic make-up. The mutations that give the virus an advantage prevail. Since SARS-CoV-2 has spread, new virus variants have therefore been forming again and again. Nevertheless, a “super virus” does not develop within a short period of time.

Many changes that initially appear to be useful for the virus also have negative effects on other areas of the virus’ function. This explains why, of the numerous variants that have been observed worldwide, only two, namely alpha and then delta, have become a global problem. Especially in the early stages of the appearance of a new variant, it is extensively examined in the laboratory. Until results are available, it is particularly important to closely monitor their spread and limit their spread to other areas.

The Omikron variant

The now described variant Omikron (B.1.1.529) was discovered in November 2021 in South Africa and shortly afterwards also detected in Botswana and Hong Kong. There are now more reports of infection from Israel, Australia and numerous European countries. On November 25th, the Omikron variant was discovered for the first time in Germany in two travelers who had arrived at Munich Airport on a flight from South Africa. Both people are currently in domestic isolation.

Additional mutations

The Omikron variant differs quite significantly from the other alpha, beta and delta variants that have been significant up to now. While there is an intersection of common mutations, Omikron also has a number of additional mutations. The large number of mutations in the spike protein attracts particular attention. Many of these mutations are located in the so-called “receptor binding domain” of all things. This is the area of ​​the spike protein that plays a crucial role in the penetration of virus particles into human cells. Changes in this area can also mean that protective antibodies no longer bind and viruses can infect cells unhindered.

Possibly higher transferability

Another group of mutations in the omicron variant concerns the so-called furin cleavage site. which is also part of the spike protein. Changes to it can lead to increased transferability of the virus or facilitate the spread of the virus into various human organs. Two other spike mutations at Omikron are also known to greatly increase the binding of the virus to the human cell receptor ACE2.

The omicron variant also has other mutations in other areas of the virus blueprint: For one of them, which is in the so-called open reading frame (ORF) 1a, there are indications that it could help the virus bypass certain parts of the immune system . Two additional mutations in the nucleocapsid gene of the virus are also known from other variants and lead to higher virus production in infected people. In doing so, they improve the ability of the virus to be transmitted from person to person.

New and known mutations

Another mutation, namely the omission of a small piece in the blueprint of the spike protein, is known as the 69/70 deletion. This change has also occurred in earlier virus variants, such as the alpha and eta variants. The advantage of this deletion for the virus is so far unclear. However, this feature can be used for diagnostic purposes: If genome sequencing is not possible, this deletion can be used in the laboratory for preliminary detection of the virus. This is because the delta variant, which is currently 99% predominant in Germany, does not contain the 69/70 deletion. However, since it occurs in the other variants mentioned, you have to be careful not to easily confuse them with the Omikron variant.

Worrying variant

Due to its special properties, the Omikron variant was classified as “worrying” by the World Health Organization (WHO) shortly after its discovery. The EU health authority (ECDC) also currently rates the risk of an EU-wide spread as “high to very high”.

The Bundeswehr Institute for Microbiology (IMB) has been monitoring the spread of virus variants among members of the Bundeswehr since the beginning of the coronavirus pandemic. As part of this SARS-CoV-2 genome surveillance by the IMB, neither the Omikron variant nor a closely related SARS-CoV-2 variant has been detected in any of the areas of application.

Safe diagnostics

The gene segments of the virus that are used for PCR diagnostics are hardly or not at all changed at Omikron. This new variant will be recognized just as reliably with the PCR tests established in the Bundeswehr and in use. The detectability of all variants of SARS-CoV-2 by rapid antigen tests has already been extensively investigated by the IMB. It has been shown that the sensitivity of the rapid antigen tests, regardless of the virus variant, is always significantly lower compared to the PCR test. Most rapid tests identify the virus through its nucleocapsid protein. The Omikron variant does not show any mutations that would lead to an impairment of the function of rapid antigen tests. However, this has yet to be confirmed in laboratory tests with an omicron virus isolate.

Further data necessary

So far, there is no sufficiently reliable data available about the so-called immune escape potential of the Omikron variant, i.e. its ability to escape the body’s defenses. Such examinations will take some time. If one considers the many mutations in the omicron variant, then it is quite conceivable that this virus variant can at least partially evade the immune system better than other currently widespread virus variants.

Vaccines continue to offer protection

But even if this were the case, it can still be assumed that the available vaccines will still offer a high level of protection against serious disease and death. The coronavirus vaccines currently used in Germany not only lead to the production of many different antibodies in the vaccinated. They also trigger the formation of special defense cells against the virus. This broad reaction of the immune system also offers protection against new variants of SARS-CoV-2. The vaccination and especially the booster refreshment are therefore still our strongest tool against the pandemic. Only through consistent vaccination can we slow down coronavirus transmission, reduce the burden on the health system and thus help protect society.

Press contact:

Press and information center of the Bundeswehr medical service
Phone: 0261/896-13103
[email protected]

Original content from: Press and Information Center of the Medical Service of the Bundeswehr, transmitted by news aktuell


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