WHO Classifies Omicron as “Variant of Concern” – Here’s What You Need to Know

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Tulio de Oliveira at the Nelson Mandela School of Medicine in Durban, South Africa. Mr. de Oliveira and members of his team announced the new Covid-19 variant. Image: Joao Silva, New York Times.

The World Health Organisation (WHO) has declared the newly discovered coronavirus variant originally identified as B.1.1.52 as a VOC – “Variant of Concern” and named it Omicron.

The WHO say they began naming the variants after Greek letters to avoid public confusion and stigma.

In its most recent publication WHO says the new variant was first reported from South Africa on the 24th of November 2021, however, the Technical Advisory Group on SARS-CoV-2 Virus Evolution (TAG-VE) confirms the first known infection was from a specimen collected a few weeks ago on the 9th of November 2021.

In the past 48 hours, Omicron has now also been identified in Botswana, Belgium, Germany, Hong Kong, Israel, Italy and the UK.

A number of countries around the world including New Zealand have decided to ban or restrict travel to and from southern Africa.

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“This variant has a large number of mutations, some of which are concerning,” states the WHO.

“Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other VOCs. The number of cases of this variant appears to be increasing in almost all provinces in South Africa”.

According to WHO several labs have indicated that for one widely used PCR test, one of the three target genes is not detected (called S gene dropout or S gene target failure) and this test can therefore be used as a marker for this variant, pending sequencing confirmation.

“Using this approach, this variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage,” reads the WHO statement.

The public is advised that there are a number of studies underway and the TAG-VE group will continue to evaluate this variant.

“WHO will communicate new findings with Member States and to the public as needed..”

What Health Experts are Saying

Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other VOCs but here’s a look at what the experts have said..

In the UK a top health official warned that vaccines would “almost certainly” be less effective against the new variant.

But Professor James Naismith, a structural biologist from the University of Oxford has said, “It is bad news but it’s not doomsday” suggesting it is early days yet and not enough is known about Omicron to cause panic based on assumptions.

Dr Mike Tildesley, a member of the Scientific Pandemic Influenza Modelling group (Spi-M), notes that only about 24% of South Africa’s population is fully vaccinated, “which could spur a rapid spread of cases there,” he told BBC.

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Meanwhile, US infectious disease chief Dr Anthony Fauci said that while reports on the new variant threw up a “red flag”, it was possible that vaccines might still work to prevent serious illness.

“Until it’s properly tested… we don’t know whether or not it evades the antibodies that protect you against the virus”, Dr Fauci told CNN.

Professor Tulio de Oliveira, the director of the Centre for Epidemic Response and Innovation in South Africa whose team detected the variant, said there was an “unusual constellation of mutations” and that it was “very different” to other variants that have circulated.

“This variant did surprise us, it has a big jump on evolution [and] many more mutations that we expected,” he said in a media briefing.

Prof de Oliveira said there were 50 mutations overall and more than 30 on the spike protein, which is the target of most vaccines and the key the virus uses to unlock the doorway into our body’s cells.

“Zooming in even further to the receptor binding domain (that’s the part of the virus that makes first contact with our body’s cells), it has 10 mutations compared to just two for the Delta variant that swept the world. This level of mutation has most likely come from a single patient who was unable to beat the virus”.

Prof Andrew Pollard, the director of the Oxford Vaccine Group, said it is “too early” to be certain whether the new variant will be able to evade current vaccinations.

“Thar is something unlikely to be known for 2-3 weeks”.

Prof Pollard is optimistic and says current vaccines will continue to prevent serious disease, going as far as suggesting Omicron will not outrun the dominant Delta variant in Europe.

Coronavirus Variants

As of July 2021, there were four dominant variants of SARS-CoV-2 spreading among global populations: the Alpha Variant (formerly called the UK Variant and officially referred to as B.1.1.7), first found in London and Kent, the Beta Variant (formerly called the South Africa Variant and officially referred to as B.1.351), the Gamma Variant (formerly called the Brazil Variant and officially referred to as P.1), and the Delta Variant (formerly called the India Variant and officially referred to as B.1.617.2).

VOI and VOC Definitions

For reference, WHO has working definitions for SARS-CoV-2 Variant of Interest (VOI) and Variant of Concern (VOC).

A SARS-CoV-2 VOI is a SARS-CoV-2 variant:

  • with genetic changes that are predicted or known to affect virus characteristics such as transmissibility, disease severity, immune escape, diagnostic or therapeutic escape; AND
  • that has been identified as causing significant community transmission or multiple COVID-19 clusters, in multiple countries with increasing relative prevalence alongside increasing number of cases over time, or other apparent epidemiological impacts to suggest an emerging risk to global public health.

A SARS-CoV-2 VOC is a SARS-CoV-2 variant that meets the definition of a VOI (see above) and, through a comparative assessment, has been demonstrated to be associated with one or more of the following changes at a degree of global public health significance:

  • increase in transmissibility or detrimental change in COVID-19 epidemiology; OR
  • increase in virulence or change in clinical disease presentation; OR
  • decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics.
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