The new COVID-19 variant: a primer

Unless you have been living under a rock, you’ll have seen that there’s a new COVID-19 variant on the scene. This block summarises the key information that has emerged so far about this new variant. It seems to be more transmissible, no more virulent, and there’s no evidence that the vaccines that are approved or nearly approved will be less effective against the variant.

  • The new variant (B.1.1.7) has been designated as a ‘variant of concern’ (VOC-202012/01) by PHE.
  • The variant has multiple mutations to the spike proteins. The variant has an unusually high number of mutations for a single cluster – suggesting some sort of genetic change event that has given the variant some superpowers!
  • The variant is thought to be up to 70% more transmissible. The R value associated with the variant seems to be about 0.4 or more greater than other circulating strains. It’s not clear at this stage what is making the variant more transmissible.
  • There is some evidence of a higher viral load associated with the variant, which may be contributing to increased transmissibility.
  • The variant first emerged in the UK around September time, and is now spreading rapidly in the South West of England and in London.
  • There is no evidence that the variant is more virulent in terms of clinical outcomes for those infected. (In fact, there’s a widely accepted idea of a biological rule of thumb that there’s generally a trade-off between virulence and transmissibility – although the evidence for this isn’t great).
  • The variant may cause an issue for detection by some laboratory tests. Fortunately, most widely used PCR assays don’t rely on a single primer binding site, so this won’t be a problem for most labs.
  • There is no evidence that vaccines will be less effective against the new variant.

For more information:

  • PHE FAQ page here.
  • PHE report on the variant here.
  • ECDC threat assessment here.
  • WHO info here.
  • Genomic epi paper here.


2 thoughts on “The new COVID-19 variant: a primer

  1. Should we be calling this a COVID-19 variant, or a SARS-CoV-2 variant? As the disease is no different that we know of?

    Just being pedantic, sorry, Jon.



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