All you need to know about Omicron Covid-19 variant

The World Health Organisation (WHO) on Monday warned that the Covid-19 variant Omicron poses a “very high” global risk and is likely to spread further and that surges in infections caused by it could have “severe consequences” in some areas.

“Given mutations that may confer immune escape potential and possibly transmissibility advantage, the likelihood of potential further spread of Omicron at the global level is high,” the WHO said on Monday.

“Depending on these characteristics, there could be future surges of Covid-19, which could have severe consequences, depending on a number of factors including where surges may take place. The overall global risk related to the new VOC (variant of concern) Omicron is assessed as very high.”

The WHO designated the variant B.1.1.529, first spotted in South Africa, as a “variant of concern” last Friday. In its report Monday, the agency said that it is “a highly divergent variant with a high number of mutations including 26-32 in the spike”.

Known unknowns

But there are still considerable uncertainties and unknowns regarding this variant, it said, repeating that sentiment on Monday.

The main uncertainties are how transmissible the variant is and whether any increases are related to immune escape, intrinsic increased transmissibility or both; and how well vaccines protect against infection, transmission, clinical disease of different degrees of severity and death.

Immune escape refers to when a person’s immune system is no longer able to recognise and eliminate a pathogen such as a virus.

Current knowledge about Omicron

Symptoms

The WHO is coordinating with researchers around the world to better understand Omicron. Studies underway or that will start shortly include assessments of transmissibility, the severity of infection (including symptoms), the performance of vaccines and diagnostic tests, and the effectiveness of treatments.  

But the South African doctor who first raised the alarm over Omicron has described its symptoms as “extremely mild”. Dr Angelique Coetzee, chair of the South African Medical Association, told the BBC on Sunday that she started seeing patients around Nov 18 presenting with “unusual symptoms” that differed slightly from those associated with the Delta variant, the most virulent strain of the virus to date and globally dominant.

“It actually started with a male patient who’s around the age of 33 ... and he said to me that he’s just [been] extremely tired for the past few days and he’s got these body aches and pains with a bit of a headache,” she told the BBC.

The patient did not have the symptoms associated with previous strains of the coronavirus, including a sore throat, cough or loss of taste or smell, but more of a “scratchy throat”.

He tested positive for Covid-19, as did his family. Dr Coetzee added that she saw more patients that day presenting with the same kinds of symptoms that differed from those of the Delta variant.

Effectiveness of vaccines

Although vaccines remain critical to reducing severe disease and death, including against the Delta variant, the WHO said it is working with technical partners to understand the potential impact of Omicron on existing countermeasures, including vaccines.

Effectiveness of current tests

The widely used PCR tests continue to detect infection, including infection with Omicron. Studies are ongoing to determine whether there is any impact on other types of tests, including rapid antigen detection tests. 

Effectiveness of current treatments

Corticosteroids and IL6 Receptor Blockers will still be effective for managing patients with severe Covid-19. Other treatments will be assessed to see if they are still as effective given the changes to parts of the virus in the Omicron variant.

Recommended action for countries

Countries should continue to implement effective public health measures to reduce Covid-19 circulation overall, “using a risk analysis and science-based approach”, the WHO advises.

“They should increase some public health and medical capacities to manage an increase in cases.”

Recommended actions for people

Some of the most effective steps individuals can take to reduce the spread of the Covid-19 virus are keeping a physical distance of at least one metre from others and wearing a well-fitting mask.

The others are opening windows to improve ventilation; avoiding poorly ventilated or crowded spaces; keeping hands clean; coughing or sneezing into a bent elbow or tissue; and getting vaccinated when it is their turn.

This information was compiled from a technical brief by the World Health Organisation.

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