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Coronavirus pandemic
ChinaScience

Explainer | Omicron: what we know and what we don’t on symptoms, transmission, and vaccines

  • Early data in South Africa suggests heavily mutated ‘variant of concern’ could outpace fast-spreading Delta
  • Disease experts are united on the need for more data as well as ramping up vaccination

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Graffiti art work in Johannesburg, South Africa, warns residents about the dangers of the coronavirus. Photo: EPA-EFE
Simone McCarthy
The new coronavirus variant Omicron has put the world on high alert, with health officials warning of possible case surges and pressure on hospitals, even as scientists scramble to understand this highly mutated strain.
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The World Health Organization has flagged the variant – reported to the health agency last week – as “very high” risk. Preliminary evidence suggests that Omicron could dodge immune defences and spread more readily than earlier strains, according to the WHO.

But the agency has also highlighted “considerable uncertainty” about this assessment, because it is too early for answers to critical questions such as whether Omicron is more transmissible, leads to more severe disease, or presents a higher risk of reinfection or of evading existing vaccines.

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Asia tightens borders as spread of new coronavirus variant Omicron clouds region’s return to travel

Asia tightens borders as spread of new coronavirus variant Omicron clouds region’s return to travel

Here’s what we do know, and what scientists are doing to work out what we don’t.

Why are scientists worried?

The Omicron variant, which was detected in southern Africa several weeks ago, caught researchers’ attention due to an unprecedented number of mutations in the “spike protein”, or the part of the virus that attaches to human cells and is typically targeted by Covid-19 vaccines and treatments.
Some of these mutations had already been flagged by researchers and Covid-19 vaccine makers for their potential to help the virus evade vaccines.

“Omicron has the kinds of mutations that vaccine makers were on the lookout for, and they have been preparing for this kind of scenario,” said immunologist Kylie Quinn, a research fellow at RMIT University in Melbourne, who called the variant’s early detection a sign that surveillance systems were working.

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How these mutations work in combination “is something that we need to watch really carefully”, she said.

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