> The first Variant Under Investigation in December 2020 (VUI – 202012/01), also known as lineage B.1.1.7, is a variant of SARS-CoV-2, the virus that causes COVID-19. The variant was first detected in the United Kingdom in October 2020 from a sample taken the previous month, and it quickly began to spread by mid-December. It is correlated with a significant increase in the rate of COVID-19 infection in England; this increase is thought to be at least partly because of mutation N501Y inside the spike glycoprotein's receptor-binding domain, which is needed for binding to ACE2 in human cells.
Correlation does not equal causation. Most of the northern hemisphere is experiencing a significant increase in cases, i.e., a second wave. It has not yet been established whether this variant exhibits a unique pathogenesis.