UK virus variant has developed concerning new mutation in small number of cases A healthcare worker oversees the coronavirus disease (COVID-19) swab test process of a man, after a new SARS-CoV-2 coronavirus variant originating from South Africa was discovered, in Tottenham, North London, Britain (REUTERS) Border controls not enough to prevent new variants, says UK expert The Covid mutation associated with lower vaccine efficacy Share Via Read Full Story London: The UK variant of the coronavirus has developed a new, concerning mutation in a small number of cases, which scientists said makes it similar to the South African and Brazilian variants and could reduce the efficacy of vaccines.