But I will note that mutations happen all the time. The more infections, the more opportunities to explore the the space of possible mutations.

Basically you wouldn't have expected this to emerge in New Zealand 11/n

This figure illustrates how the 'new variant' (proper name lineage 'B.1.1.7') has more differences than you would expect. 12/n

There is much more discussion in this excellent and thorough blog post https://virological.org/t/preliminary-genomic-characterisation-of-an-emergent-sars-cov-2-lineage-in-the-uk-defined-by-a-novel-set-of-spike-mutations/563 (thx @WvSchaik for alerting me) but a few headline comments follow 13/n

The S:N501Y mutation is known to increase binding affinity to the receptor. Doesn't necessarily mean more transmissible. But has a phenotype and has been seen multiple times. The variant *also* has... 14/n

P681H. Which is next to the furin cleavage site. This is thought to be important (but I'd leave it to the likes of @angie_rasmussen to discuss as I don't think I know enough) https://www.cell.com/iscience/pdf/S2589-0042(20)30397-7.pdf 15/n

and then a deletion in the spike protein. The 69 & 70th amino acids are deleted. This has been seen several times previously, and linked to immune evasion but also general stuff going on with the receptor binding domain 16/n

A note - it is a tribute to the extraordinary work of so many working with @CovidGenomicsUK that we know this much. I've been privileged to know and work with many of them for years. We are all in their debt. 17/end