KEY POINTS
  • The evidence is still at a preliminary stage and is being assessed by the New and Emerging Respiratory Virus Threats Advisory Group, which advises the British government.
  • The variant, discovered in the U.K. and known as B.1.1.7, has an unusually high number of mutations and is associated with more efficient and rapid transmission.
UK Prime Minister Boris Johnson speaks during a media briefing on coronavirus (COVID-19) at Downing Street on January 15, 2021 in London, England.

LONDON —There is "some evidence" a new Covid variant first identified in the U.K. could be more deadly than the original strain, British Prime Minister Boris Johnson said Friday.

"We've been informed today that in addition to spreading more quickly, it also now appears that there is some evidence that the new variant — the variant that was first discovered in London and the southeast (of England) — may be associated with a higher degree of mortality," Johnson told a news conference.