Is the latest COVID-19 virus variant a cause for concern?

Philippa Brice

26 November 2021

Blog

There are widespread reports of concerns and policy actions in response to today’s news about a new variant of the SARS-CoV-2 virus.

The new variant in question, B.1.1.529, was identified in South Africa, and prompted a rapid investigative response from the health authorities there for two reasons: the genome sequence of the viral variant, and the speed with which it is spreading in the local population.

Genomic insights

Genomic sequencing and analysis of SARS-CoV-2 has been crucial for both scientific understanding and public health control measures. Scientists worldwide monitor and share information about these sequences, which change over time. Viruses multiply very quickly and accumulate mutations (changes to their genome sequences) readily; where these changes affect the properties of the virus, they may affect how infectious (able to spread between people) or virulent (likely to cause severe illness in infected people) the virus is. They can also have an impact on the efficacy of vaccines. Both issues matter for health authorities considering how much of a threat a new variant may pose, and how best to protect the public against it.

Mutations that help a viral variant spread provide a competitive advantage over other viral variants, so that variant becomes more common. This was exemplified by the SARS-CoV-2 Delta variant, which was first identified in India in December 2020 and proved to be highly infectious, rapidly becoming the predominant variant infecting people around the world.

Understanding the new variant

The B.1.1.529 variant has an unusual and novel genome, with multiple mutations including many in the region of the genome that controls production of the viral spike protein. This is the external surface element of the virus that is both critical for viral binding and entry to human host cells, and also plays an important role in human immune system recognition of the virus. The large number of mutations in this region are therefore potentially dangerous.

On the ground, there is clear evidence that the variant may be more transmissible, but not yet whether it causes different or more severe disease, or whether the protective effects of vaccination or previous infection with other variants are reduced against it.

Expert Sharon Peacock, Professor of Public Health and Microbiology at the University of Cambridge and Director of COG-UK (the COVID-19 genomics consortium that is a global pioneer of sequencing and analysis) observed:

“The epidemiological picture suggests that this variant may be more transmissible, and several mutations are consistent with enhanced transmissibility.  Mutations are also present that have been associated in other variants with immune evasion.  But the significance of many of the mutations detected, and the combination of these mutations, is not known.”  

Next steps

The World Health Organization (WHO), which monitors infectious disease threats including COVID-19, has a process by which viral variants may be designated ‘variants of concern’ (VOCs) if they are considered to pose a significant public health threat. VOC status is conferred on variants where evidence shows that the virus is spreading in a new and dangerous way; is causing new forms or more serious forms of disease; is less responsive to existing control measures such as diagnostics, vaccines or treatments; or any combination of these factors. The WHO will decide today whether there is sufficient evidence to designate B.1.1.529 a new variant of concern. If there is not, further evidence may emerge in the coming weeks that changes their decision; or it may demonstrate that the variant poses less risk than previously feared.

Meanwhile, the UK government has wisely decided to take preventative steps in case the new variant does prove to be dangerous; new quarantine measures for travellers arriving from South Africa and other countries in the region will reduce the risks of rapid spread of the new variant to the local population.

Although there is understandable and reasonable concern about the new variant, it is good news that the genomic surveillance and other monitoring and reporting systems are functioning properly to identify potentially dangerous new viral variants, promoting further investigations and where appropriate, actions to limit their impact. This is science-informed policy and decision-making in action – and in a world where the rapid emergence of new and evolving infectious disease threats is now widely understood, the value of ongoing investment in growing and supporting these systems can be clearly seen.

To find out more about COVID-19 genomic surveillance and variants of concern, read our reports for the Foundation for Innovative New Diagnostics (FIND).

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