Omicron Q&A: How concerned are scientists about the new Covid-19 variant?

WHO assessing significance of new variant as EU and UK suspend flights from southern African countries

I’ve just heard about that new Covid-19 variant they’ve found in South Africa. What’s all the fuss about?

Yes, here we go again; a new variant of the virus has been discovered and it has even normally urbane scientists concerned. The World Health Organisation has christened it Omicron.

Scientists are concerned because it is the most heavily mutated version of the virus identified so far. These are very early days but the variant, also known as B.1.1.529, is spreading fast in one province in South Africa, there have been reports of cases in Israel and Hong Kong, and one case has been reported in Belgium.

Why should we be concerned?

This latest turn in the pandemic raises all the old questions we have about each new variant. How fast can it spread? Can it bypass the protection provided by vaccines? Is it more lethal? And what can we do to stop it?

But we’ve had scare stories about variants before, and they didn’t amount to much?

Yes, some new versions of Covid-19 didn’t prove much of a threat, usually because they couldn’t spread efficiently. However, the Alpha and, later, the Delta variants turned out to be significantly more problematic than the virus that originated in Wuhan, China. Delta, which is more transmissible, has been completely dominant in Ireland since late spring.

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So what do we know so far?

Very little, but the initial red flags raised by scientists in South Africa are being taken seriously. The earliest sample originated in Botswana. Travel bans between southern African states and other parts of the world are being put in place.

Prof Tulio de Oliveira, director of the Centre for Epidemic Response and Innovation in South Africa, has described an “unusual constellation of mutations” on the variant, which make it “worrisome on the mutational level”.

There are 50 mutations overall, he says. This includes more than 30 on the spike protein, which is the route of entry of the virus into the body and also target of most vaccines. Specifically, in the receptor binding domain, where the virus makes contact with cells, there are 10 mutations, compared to just two for the Delta variant.

The WHO says “preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other variants of concern”.

Uh-oh. This sounds bad?

It depends on what these mutations are actually doing. It could mean that Covid-19 vaccines would not be as effective with this variant, but we don’t know this yet. Where some of the mutations on B.1.1.529 were seen previously in other variants, they made them more transmissible. Other mutations in this variant are completely new, so their effect is unknown.

Any positives?

Yes. We’re far more aware of the threat posed by variants than we were a year ago, when Alpha wrecked Christmas 2020 for many Irish people. We’re learning about this new variant quickly, thanks to South Africa’s nifty scientists. So far, only 77 cases have been fully confirmed in Gauteng province, though the speed of onset have led researchers to conclude that 90 per cent of cases there may already be this variant.

It seems the variant can be detected using a PCR test so we should be able to track it quickly. The wider world has reacted quickly, with many European countries on Friday following the lead of the UK in banning flights from southern Africa. EU member states agreed to introduce restrictions on all travel into the EU from 7 countries in the Southern Africa region including tests, quarantine and contact tracing.

Can we stop it coming here?

Assuming it turns out to be a real threat, probably not. After all, as we have seen with the Belgian case, it is already in Europe. But we can slow down the spread of cases and buy time through travel curbs, and this could be critical for the winter period in the first instance. Minister Stephen Donnelly says he is "very concerned" but for now there are no known cases in Ireland.

And what happens now?

In the real world, the variant will inevitably spread. In the lab, scientists will be monitoring its progress, and studying its characteristics and tweaking vaccines. More travel restrictions seem likely if the threat posed by the variant is sustained.

Paul Cullen

Paul Cullen

Paul Cullen is Health Editor of The Irish Times