Alpha to omicron: an overview of virus variants

The virus continues to mutate: while the alpha variant of the corona virus was responsible for the third wave, the delta variant of SARS-CoV-2 now dominates and is the trigger of the fourth corona wave. But the next variant is already lurking – Omicron (B.1.1.529) could outperform Delta. An overview of all dangerous variants can be found here.

In order not to jeopardize the  progress of vaccination  and the success to date, the various virus variants are evaluated by the World Health Organization (WHO) and the national authorities (Robert Koch Institute). Particularly striking variants are named after letters of the Greek alphabet.

WHO assessment of virus variants

The virus variants are assessed based on their characteristics as follows:

• Variants under observation (VOI):  These are virus lines that have different, worrying mutations that are responsible for frequent infections and occur in several countries.
• Variants of concern (VOC):  These virus lines are very different from the structure of the original type. They can be more infectious and virulent or reduce the immune response of recovered and vaccinated people.

1. Virus variant alpha: first appeared in Great Britain

The alpha variant (B1.1.7) was first detected in the UK and is classified as of concern. However, it has already been replaced by the Delta variant.

Special characteristics are the higher  number of reproductions  and a higher risk of infection compared to the original type.

2. Beta variant: dominant in South Africa

The beta variant is particularly dominant in South Africa and is one of the worrying variants in Germany. This is what makes B.1.351 so special:

• Lower vaccination protection for fully vaccinated people
• Low vaccination protection by  AstraZeneca
• Higher risk of infection possible

So far, the virus variant from South Africa has rarely occurred in Germany.

3. Gamma mutation (P1): responsible for the big wave in Brazil

The worrying variant is responsible for the high number of infections in Manaus, Brazil. Despite a high number of people who have recovered, the number of COVID-19 diseases and, as a result, the number of deaths increased.

Gamma accounts for only a small proportion of new infections in Germany. Gamma has similar properties to the Beta variant in its structure and behavior.

4. Delta (B.1.617.2): dominant in Europa

The delta variant is worrying and responsible for the current fourth wave. The mutation was first detected in India and is a particularly well-adapted mutation of the  coronavirus :

• Delta may reduce the immune response of vaccinated individuals.
• Due to the structures of the variant, there is a higher risk of infection.
• The dangerous variant Delta-Plus also uses lung cells and triggers severe courses.
• Delta triggers new and different symptoms that are harder to distinguish from a  cold  .

The Delta variant currently dominates throughout Europe

5. Lambda (C.37): observed by WHO

This virus variant is currently under close observation by the World Health Organization. She is initially at home in South America (Peru, Argentina and Chile). The lambda variant could trigger a lower immune response and be   less well fought by the immune system . Studies on the newer variant are currently underway.

6. Omicron (B.1.1.529) – new variant with many mutations

The virus variant B.1.1.529, also known as the omicron, has been classified as a concern by the World Health Organization (WHO) since November 2021. The mutation was initially registered in southern Africa, but the first cases have also been reported in Europe. So far, little has been learned about the mutation. However, we now know the following:

• The omicron variant is quickly and easily detected by PCR tests.
• Nine relevant mutations in the spike protein, which enables the virus to attach to human cells, could increase the risk of infection with B.1.1.529.
• Due to the changes, the variant could reduce vaccination protection and thus increase the number of breakthrough infections.

Experts are currently working on the intensive sequencing of the new variant, and vaccine manufacturers are already examining how much Omikron could reduce the effectiveness of the vaccines.

7. Other virus variants

In addition to the virus variants presented so far, the following mutations are being sequenced and are under observation:

• Epsilon (B.1.424/B.1.429):  Epsilon is more prevalent in California and may increase the risk of infection and reduce the immune response. It is already classified as a concern in the US.
• Zeta (P2): Erste Studien zeigen, dass bei einer weiteren Variante aus Brasilien die Neutralisierung der Antikörper reduziert ist. Genaue Untersuchungen der Daten laufen aktuell noch. Die WHO beobachtet die Zeta-Variante.
• Eta (B.1.525): Auch die Eta-Variante könnte eine erhöhte Übertragbarkeit und eine Veränderung der Immunantwort auslösen. Bisher ist die Mutation in Zentralafrika, wie Angola und Nigeria, und teilweise in Großbritannien in Erscheinung getreten. In Deutschland wurde bisher eine Infektion nachgewiesen.
• Theta (P3): Theta wird ebenfalls beobachtet und wurde aktuell auf den Philippinen, in Japan und den USA registriert, sehr vereinzelt auch in Deutschland. Wie alle anderen Mutationen könnte auch Theta die Immunantwort reduzieren und eine höhere Übertragungsrate aufweisen.
• Iota (B.1526): Die Virusvariante kommt vermehrt in New York vor. Sie soll Antikörper gezielt umgehen können und aufgrund ihrer strukturellen Veränderung für eine höhere Übertragbarkeit sorgen, da sie sich enger an menschliche Zellen bindet.
• Kappa (B.1.617.1): Kappa wurden ebenfalls erstmals in Indien registriert und steht aktuell unter Beobachtung. Auch sie steht im Zusammenhang mit einer verringerten Immunität und einer höheren Übertragbarkeit.
• Mu (B.1.162) steht seit September unter der Beobachtung (Variant of Interest/VOI) der WHO. Die Mu-Variante ist besonders in Südamerika aktiv und sorgt aufgrund Veränderungen des Spike-Proteins für ein erhöhtes Infektionsrisiko.

Due to new changes in the structure of the virus and in the symptoms, people, even those who have been fully vaccinated, should be tested for corona if they suspect it (e.g. if they have cold symptoms). A PCR test is recommended here, as this provides the most reliable results. AHA rules are still recommended.