March 2, 2021

expert comment on variants of SARS-CoV-2

A general comment from Dr Jeffrey Barrett on what we know about the different SARS-CoV-2 variants variants (including the South African, Brazilian and Kent variants).

Dr Jeffrey Barrett, Director of the SARS-CoV-2 Genomics Initiative at the Wellcome Sanger Institute, said:

“We really want to know the answer to two questions about coronavirus variants of concern: are they more transmissible, and do they evade some of our immunity, whether from a vaccine or a previous infection?  It turns out that these two questions are actually closely linked, because a variant that is less well neutralised by our immune response will spread faster in a place where lots of people have been previously infected, but might not spread as well as other variants in a place with low levels of prior infection.

“We have now seen a growing body of evidence from lab experiments that B.1.351 and P.1 are less well neutralised by our immune response from vaccines or prior infection, and that likely explains part of why they have spread rapidly in South Africa, and Brazil, respectively.  By contrast, experiments don’t show a large difference in the immune response to B.1.1.7, and the ongoing success of vaccines in reducing infections in the UK (which are nearly all B.1.1.7 now) suggests that it is well neutralised by existing immunity.

“So the fast spread of B.1.1.7, first in the UK, and then in many other countries, must have some other biological explanation – it can cause enormous short term problems, but hopefully these can be contained by vaccines.  B.1.351 and P.1 don’t yet seem that they spread quickly in the UK given the restrictions that were needed to contain B.1.1.7.  But because any reduction in vaccine efficacy is worrisome, our goal should be to keep them from getting a foothold here as restrictions are eased, so continued vigilance in our genomic surveillance is essential.”

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.