Early transmissibility assessment of the N501Y mutant strains of SARS-CoV-2 in the United Kingdom, October to November 2020

Euro Surveill. 2021 Jan;26(1):2002106. doi: 10.2807/1560-7917.ES.2020.26.1.2002106.


Two new SARS-CoV-2 lineages with the N501Y mutation in the receptor-binding domain of the spike protein spread rapidly in the United Kingdom. We estimated that the earlier 501Y lineage without amino acid deletion Δ69/Δ70, circulating mainly between early September and mid-November, was 10% (6-13%) more transmissible than the 501N lineage, and the 501Y lineage with amino acid deletion Δ69/Δ70, circulating since late September, was 75% (70-80%) more transmissible than the 501N lineage.

Keywords: 20B/501Y.V1; COVID-19; N501Y; SARS-CoV-2; United Kingdom; VOC-202012/01; fitness; lineage B.1.1.7; spike protein; transmissibility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19 / diagnosis
  • COVID-19 / epidemiology
  • COVID-19 / transmission*
  • COVID-19 / virology*
  • Genetic Markers
  • Genetic Variation
  • Genome, Viral
  • Humans
  • Mutation*
  • Phylogeny
  • SARS-CoV-2 / genetics*
  • SARS-CoV-2 / pathogenicity
  • Spike Glycoprotein, Coronavirus / genetics*
  • United Kingdom / epidemiology


  • Genetic Markers
  • Spike Glycoprotein, Coronavirus
  • spike protein, SARS-CoV-2