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.