Monday, December 21, 2020

The Crown Evolves

Viral genomes can mutate rapidly.  Extensive genomic sequencing of SARS-CoV-2 in the United Kingdom during 2020 has identified several distinct phylogenetic lineages.  In a report published on December 19, 2020, the Covid-19 Genomics UK Consortium ("COG-UK") describes several notable features of one these clades, which has been designated B.1.1.7:

Has 17 mutations (14 replacements and 3 deletions) including: T1001I, A1708D, I2230T, SGF 3675-3677 del In the ORF1ab; 69-70 del, Y144 del, N501Y, A570D, P681H, T716I, S982A and D1118H in the Spike; Q27stop, R52I and Y73C in ORF8; D3L and S235F in the N.  Noteworthy N501Y enhances ACE2 binding affinity, 69-70del has immunological role and it is associated with some diagnostics failures, and P681H occurs at the furin cleavage site, known for biological significance in membrane fusion[.]

Worries that rapidly-spreading SARS-CoV-2 B.1.1.7 may be associated with higher infectiousness have led a number of countries to suspend direct flights from the United Kingdom.