What We Know About The Omicron Variant

Final week, the WHO introduced {that a} new variant of SARS-CoV-2, often called lineage B.1.1.529, was a variant of concern and would henceforth be often called Omicron. The response was dramatic. Financial markets dipped. Governments began closing borders.

Anthony Fauci explicitly acknowledged what many individuals instantly suspected: Omicron is sort of definitely already circulating elsewhere around the globe. The checklist of nations with recognized or suspected circumstances of Omicron consists of Australia, Austria, Belgium, Botswana, the Czech Republic, Denmark, Germany, Hong Kong, Israel, Italy, the Netherlands, South Africa, and the UK, though most recognized or suspected circumstances are folks arriving from Africa.

So, what will we find out about this variant? The reality is we don’t at the moment know a lot that’s clinically or epidemiologically related. What we do know comes primarily from having sequenced the variant’s genome, and it’s attention-grabbing.  The evolutionary phylogeny at the moment estimated by the Nextstrain project means that Omicron shouldn’t be associated to any of the at the moment widespread strains, together with Delta, or the beforehand widespread Alpha variant. Omicron has a lot of mutations that distinguish it each from the unique pressure of SARS-CoV-2 and the opposite extensively circulating strains.

Risk of vaccine evasion 

Thirty-two separate mutations are related to only one gene, often called S, which codes for the Spike protein. The Spike protein is vital as a result of it’s discovered on the floor of the virus particle, which makes it an identifiable goal for immune response. It’s due to this fact additionally an ordinary vaccine goal. The Pfizer-BioNTech, Moderna, and Johnson & Johnson Covid-19 vaccines all goal Spike.

The concern is that thirty-two mutations is sufficient to make the Omicron variant of the Spike protein look fairly completely different from the proteins that these vaccines have been designed to focus on. A study of experimentally engineered viruses revealed earlier this fall confirmed that twenty mutations was adequate for a variant to keep away from the neutralizing antibodies generated by individuals who had both recovered from a pure an infection or who obtained an mRNA vaccine. For these causes it’s fairly believable that Omicron could possibly be a so-called escape variant. It’s nonetheless simply hypothesis, however well-founded, as defined in an insightful twitter thread by virologist Florian Krammer 

Risk of elevated transmissibility 

Along with the mutations that may confer immune escape, there are additionally three mutations on the furin cleavage website (additionally on the Spike protein). That is of curiosity as a result of this a part of the genome is essential to transmission and could also be related to elevated transmissibility. A detailed description of Omicron’s mutations is offered by Emma Hodcraft at covariants.org. 

When will we all know extra?

Pfizer said on Friday that the corporate expects to have knowledge on resistance (if any) of Omicron to its vaccine inside 2 weeks. If wanted, a brand new vaccine could possibly be able to ship inside 100 days (topic to approval). 

What occurs subsequent?

The underside line is that we don’t at the moment know what the epidemiological affect of Omicron shall be. As a result of a big fraction of latest South African isolates are Omicron, there’s concern that it might have the flexibility to displace Delta in populations the place it’s launched. Alternatively, circumstances have been comparatively low total in South Africa on the time that Omicron emerged. What’s extra, the isolates we’ve will not be a random pattern of viruses at the moment circulating in South Africa, so the impression that Omicron could also be beginning to dominate could possibly be exaggerated.

I anticipate that over the subsequent two to 4 weeks we’ll study much more about Omicron. Within the meantime, the overwhelming majority of circumstances around the globe, together with the surges of Covid-19 seen within the US and Europe, will proceed to be attributable to the Delta variant, which is sort of successfully neutralized by vaccines.