Variant B.1.1.529, designated Omicron, has 50 mutations that may mean that it is more transmissible and can evade current COVID-19 vaccines

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A new variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—variant B.1.1.529, designated Omicron—has emerged that experts say may be more transmissible and have the potential to reduce the effectiveness of current COVID-19 vaccines.

The UK Health Security Agency (UKHSA) has listed variant B.1.1.529 as a variant under investigation with very high priority—the only variant with such a designation.

Significant mutations 

The variant has around 50 mutations, 30 of which are in the spike protein.

Officials say that these mutations are ‘significant’ and, pending further investigation, may ‘change the behaviour of the virus with regards to vaccines, treatments, and transmissibility’.

The first genomes of the B.1.1.529 variant were uploaded to the international GISAID database on 22 November 2021.

At a briefing hosted yesterday by South Africa’s Health Ministry, epidemiologist Tulio De Oliveira said that 77 cases had been detected in South Africa, four in Botswana, and one in Hong Kong involving a traveller from South Africa.

The new variant ‘is a reason for concern’, he said.

In a press release, Dr Jenny Harries, UKHSA Chief Executive, said: ‘This is the most significant variant we have encountered to date and urgent research is underway to learn more about its transmissibility, severity, and vaccine-susceptibility.

‘The results of these investigations will determine what public health actions may limit the impact of B.1.1.529.’

Commenting on the development for the Science Media Centre, Sharon Peacock, Professor of Public Health and Microbiology at the University of Cambridge, said that the variant contained several mutations that were ‘consistent with enhanced transmissibility’, and that ‘mutations are also present that have been associated in other variants with immune evasion’.

Francois Balloux, Professor of Computational Systems Biology at University College London, said: ‘We can confidently predict B.1.1.529 may partly bypass immunisation provided by vaccination and prior infection’, but that ‘any prediction about its transmissibility and virulence feels premature’.

The emergence of B.1.1.529 ‘could well represent another setback after the emergence and global spread of the Alpha and Delta variants’, he added.

Travel restrictions

On 26 November 2021, the Secretary of State for Health and Social Care, Sajid Javid, said in an address to Parliament that the Government would be imposing travel restrictions as a precautionary measure, but that the UK was in a ‘strong position’.

The Health Secretary added that it was a ‘fast-moving situation’ and subject to ‘a high degree of uncertainty’. However, the Government is concerned that the new variant ‘may pose substantial risk to public health’, as it is ‘highly likely that it has now spread to other countries’.

South Africa, Botswana, Lesotho, Eswatini, Zimbabwe, Namibia, Malawi, Mozambique, Zambia, and Angola have so far been added to the UK’s travel red list. Direct flights from these countries have been banned until hotel quarantine arrangements have been established.

Despite these restrictions, nine cases of the Omicron variant have now been identified in the UK—three in England and six in Scotland.

This article originally appeared on Medscape, part of the Medscape Professional Network.


Lead image: artegorov3@gmail/

Image 1: artegorov3@gmail/