LONDON (REUTERS) - Britain on Sunday (Dec 12) raised its Covid-19 alert level to level 4 from level 3 at the recommendation of its chief medical officers, in response to the rapid spread of the Omicron variant of the virus.

"Early evidence shows that Omicron is spreading much faster than Delta and that vaccine protection against symptomatic disease from Omicron is reduced," the government said in a statement.

The upgrade to level 4 means health authorities think rates of transmission are high and putting pressure on healthcare services.