SARS-CoV-2 Alpha variant

The Alpha variant (B.1.1.7) was a SARS-CoV-2 variant of concern. It was estimated to be 40–80% more transmissible than the wild-type SARS-CoV-2 (with most estimates occupying the middle to higher end of this range). Scientists more widely took note of this variant in early December 2020, when a phylogenetic tree showing viral sequences from Kent, United Kingdom looked unusual.

The variant began to spread quickly by mid-December, around the same time as infections surged. This increase is thought to be at least partly because of one or more mutations in the virus' spike protein. The variant was also notable for having more mutations than normally seen. By January 2021, more than half of all genomic sequencing of SARS-CoV-2 was carried out in the UK. This gave rise to questions as to how many other important variants were circulating around the world undetected.