Interviewer: Professor Emma Thomson, thank you very
much for taking the time to do this interview with us today
to discuss the phenomenon by which SARS-CoV-2 variants emerge,
and in particular talk about which of these are the most worrisome and why?
First of all, could you provide us with some background
to you're recently published research in the journal
Cell addressing the range and breadth of SARS-CoV-2 mutations identified to date,
and in particular the study of the N439K mutation.
Prof. Thomson: Sure, hello. Well, many thousands of mutations have now been
described in the SARS-CoV-2 genome since it first emerged at the end of 2019.
and these, as in all viruses, arise randomly as the virus replicates,
and as it passes from person to person in the case of
SARS-CoV-2 very rapidly and right across the world.
Most of these mutations are of no consequence at all,
but when the virus comes under pressure some of
these mutations just through coincidence may be beneficial to the virus,
and most RNA viruses replicate or divide inaccurately.
But because this one,
SARS-CoV-2 has an exonuclease or a proofreading function which is encoded by NSP14.
This actually proofreads the virus as it replicates and it makes the rate of change
actually quite slow compared to other viruses like HIV or influenza.
The rate of new mutations was occurring maybe around two changes per
month until September or October 2020 when
suddenly we spotted what we now refer to as new variants emerging that had for example