Omicron: Everything we know and why experts say it will not bring us into a pandemic

Recent case streams COVID-19 in parts of South Africa are attributed almost entirely to the new strain Omicron.

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The very recent identification of a new strain of SARS-CoV-2 leading to disease COVID-19 has caused global concern with particularly significant health and socio-economic implications. Nevertheless, the majority of experts note that even in the possibility of confirming the most unfavorable scenarios, we will not return to the original state of the pandemic.

The Doctors of the Therapeutic Clinic of the Medical School of the National and Kapodistrian University of Athens Theodora Psaltopoulou, Giannis Danasis, Panos Malandrakis and Thanos Dimopoulos (Rector of EKPA) summarize the latest data.

The new strain was first identified in samples of patients with COVID-19 collected on November 11, 2021 in Botswana, and was soon identified in South Africa as well as in a vaccinated traveler who had returned to Hong Kong after a trip to South Africa between October 22 and November 11, 2021. Strain B. 1.1.529 was found in another person in the hotel where the traveler with whom he came in contact was in quarantine. Then, new cases COVID-19 due to the new strain were recorded in Israel and Belgium.

It is worth noting that the case found in Belgium had not been vaccinated or had previously been COVID-19 and had traveled only to Egypt and Turkey, and developed symptoms 11 days after traveling to Egypt via Turkey in early November 2021. The fact raises concerns about the spread of the new strain in more countries not only in Africa but also on other continents. Cases COVID-19 due to the new strain have also been recorded in the United Kingdom, Germany, Italy. To date, there is no evidence to suggest that infection with the new strain leads to more severe symptoms.

"Concern strain"

The World Health Organization named the new strain B.1.1.529 Omicron and described it as a "strain of concern". The new strain B.1.1.529 displays a particularly alarming profile of 32 mutations in the S-protein of the S gene that the virus uses to invade human cells. The number and type of mutations are causing concern in the international scientific community.

Virologist Tom Peacock of Imperial College London notes that he is the first strain of SARS-CoV-2 with two mutations encoding the furin cleavage site in protein S, P681H and N679K. These mutations, along with H655Y, are associated with improved ability of the virus to enter human cells and increased transmission potential, and it is worth noting that the P681H mutation is also detected in the Delta strain. In addition, deletion of nsp6 (Δ105-107) may be associated with the escape of natural human immunity, as it leads to antagonism of the action of interferons that have antiviral activity, and may also be associated with increased transmissibility.

This mutation has also been detected in the strains' Alpha, Beta, Gamma and Lambda. In addition to the S protein mutations, there are other disturbing mutations in the Omicron strain such as nucleocapsid R203K and G204R, which are associated with increased virulence and have also been detected in the Alpha, Gamma and Lambda strains. Mutations detected in the new Omicron strain may also increase the risk of re-infection, escape of the protection offered by the vaccine, and reduced effectiveness of monoclonal antibody therapies against SARS-CoV-2. However, further research is needed to determine the exact level of risk.

Particularly worrying are the epidemiological data from the SARS-CoV-2 genome sequencing data in South African cases, where it appears that the new strain B.1.1.529 predominates over the delta strain. Recent case streams COVID-19 in parts of South Africa are attributed almost entirely to the new strain Omicron. Taking all of the above into account, epidemiological risk assessment models predict that the Omicron strain has a clear rapid dominance advantage over the Delta strain.

Regarding the diagnosis of the new Omicron strain, it is possible to rapidly detect with existing polymerase chain reaction (PCR) technology and the S-gene dropout test before confirmation by sequencing the virus genome, which requires more time.

Pfizer, Moderna and Novavax have already announced that they are working fast to verify the effectiveness of their vaccines against the new Omicron strain and to adapt them appropriately to offer strong protection against the new strain.

In conclusion, the new Omicron strain of SARS-CoV-2 raises serious concerns about the potential for transmission, re-infection and escape the protection offered by vaccines. Clear data in relation to the above will be available within the next four weeks, according to the Professors of EKPA. In this context, they add, it is considered even more necessary to be vaccinated with the third booster dose to achieve maximum protection against serious disease. COVID-19, as well as the constant vigilance for the timely detection and isolation of cases in order to stop the transmission chain. In addition, they note, increasing vaccinations in developing countries should be a priority for developed countries and international organizations.