Behind the numbers: The UK’s gene sequencing labs are at the forefront of global efforts to trace and identify every single case
All viruses change through random mutations. Through genomic sequencing we now know that the UK epidemic was seeded by more than 1,000 distinct variants from people returning from Italy, Spain and France in February and March 2020, explaining why we got off to such a bad start.
These tiny changes are mostly inconsequential. Sometimes the virus gets lucky and spreads more easily, or causes more severe illness, in which case it earns the label Variant of Concern (VOC). In December, the rising B.1.1.7 lineage (also snappily known as VOC-202012/01) instigated new restrictions across south-east England, wrecking the tier system and ruining Christmas plans. This became known as the “UK variant” in other countries, while in the UK it is the “Kent variant”. It is unclear what people in Kent call it. More than 100,000 cases have been confirmed by sequencing.