Evolutionary dynamics of SARS-CoV-2
Trevor Bedford (@trvrb)
Associate Professor, Fred Hutchinson Cancer Research Center
26 Mar 2021
Pew Annual Meeting
Slides at: bedford.io/talks
Over 800k SARS-CoV-2 genomes shared to GISAID and evolution tracked in real-time at nextstrain.org
SARS-CoV-2 lineages establish globally in February and March
Spike protein is critical for cell invasion by the virus and is the primary target for human immune response
Spike mutations 484K and 501Y appearing repeatedly
Emergence of 501Y.V1 (B.1.1.7) in the UK
Emergence of 501Y.V2 (B.1.351) in the South Africa
Emergence of 501Y.V3 (P.1) in the Brazil
Repeated convergent evolution across sites in spike
Up to December, my expectation was evolution as seen in seasonal coronaviruses with flu B-like rates of evolution
Rapid spike S1 amino acid evolution in SARS-CoV-2
SARS-COV-2 spike S1 evolution similar to evolution of flu H3N2
501Y.V2 shows an ~8-fold drop in neutralization titer, equivalent to ~3 years of H3N2 evolution
Generally, I suspect we're looking at a data-rich version of the influenza strain selection process
- mRNA vaccines allow faster turnarounds and may push for more regional strategies
- Work directly from human serological data rather than naive animals
- Multiple valencies possible, clinical trials should be conducted now comparing regimens
Acknowledgements
SARS-CoV-2 genomic epi: Data producers from all over the world, GISAID and the Nextstrain team
Bedford Lab:
Alli Black,
John Huddleston,
James Hadfield,
Katie Kistler,
Louise Moncla,
Maya Lewinsohn,
Thomas Sibley,
Jover Lee,
Kairsten Fay,
Misja Ilcisin,
Cassia Wagner,
Miguel Paredes,
Nicola Müller,
Marlin Figgins,
Eli Harkins
