Question: I was listening to the news about the new virus strain in the UK.  Where did the mutations come from?

Answer: There is currently no data on the precise nature of the event(s) that led to the new variant.  The current hypothesis is that the new variant came from a chronically infected individual who was likely immunocompromised.  Basically, the idea is that the virus adapted within a patient as the virus was faced with different pressures inside the body– weakened immune system allowing the virus to persist plus convalescent plasma treatment (antibody therapy) pushing the virus to adapt.  This hypothesis is further described in the COVID Genomics UK Consortium’s preliminary analysis, “Preliminary genomic characterisation of an emergent SARS-CoV-2 lineage in the UK defined by a novel set of spike mutations.”  

Consortium scientists write that this variant (B.1.1.7) carries “an unusual number of virus genetic changes” (17) that is “unprecedented” since circulating SARS-CoV-2 lineages generally accumulate no more than 1-2 mutations per month.  Scientists hypothesize that “the unusual genetic divergence of lineage B.1.1.7 may have resulted, at least in part, from virus evolution with a chronically-infected individual.”  Many questions abound.  If you’re interested in reading more, but not keen on reading the Consortium’s report, the BBC published a helpful synthesis yesterday, “New coronavirus variant: What do we know?”