Mr. Johnson told a Downing Street briefing: “The new variant could increase the R by 0.4 or more, and although there’s considerable uncertainty, it may be up to 70% more transmissible than the old variant, the original version of the disease.”
England’s Tier 4 is the equivalent of the old national lockdown restrictions and began Dec. 20.
It prevents Christmas relaxation for gatherings in Tier 4, aside from support bubbles.
Non-essential shops, gyms, and hairdressers will also close. People shouldn’t enter or leave Tier 4.
In the rest of England, special Christmas measures are reduced to 1 day down from the previous 5.
Mr. Johnson had previously said it would be “inhuman” to cancel Christmas.
“When the science changes, we must change our response,” Mr. Johnson said. “When the virus changes its method of attack, we must change our method of defence. And as your Prime Minister I sincerely believe there is no alternative open to me.”
He added: “We’re sacrificing the chance to see our loved ones this Christmas so we have a better chance of protecting their lives so that we can see them at future Christmases.”
He denied he’d been slow to react to rising cases and evidence around the virus variant.
Rest of the UK
The PM’s announcement for England followed calls with the cabinet, and with the leaders of Scotland, Wales, and Northern Ireland.
Wales has brought forward its planned national lockdown to start at midnight with rules eased on Christmas Day. First Minister Mark Drakeford said: “The situation is incredibly serious. I cannot overstate this.”
Seventeen new variant cases have already been identified in Scotland. First Minister Nicola Sturgeon said: “We do now face a very serious situation. It is, in fact, probably the most serious and potentially dangerous juncture we have faced since the start of the COVID pandemic in February, and March.”
Although she said the situation in Scotland is not as severe as other parts of the UK, preventative measures were needed.
Restrictions will now only be lifted on Christmas day itself, and there’s a ban on non-essential travel to and from the rest of the UK.
Level 4 measures will be applied to all of mainland Scotland for 3 weeks from Boxing Day.
Ms. Sturgeon said making the announcement about Christmas made her want to cry.
The variant was identified through Public Health England genomic surveillance. Chief Medical Adviser Professor Chris Whitty issued a statement saying: “As a result of the rapid spread of the new variant, preliminary modelling data and rapidly rising incidence rates in the South East, the New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) now consider that the new strain can spread more quickly.
“We have alerted the World Health Organisation and are continuing to analyse the available data to improve our understanding.
“There is no current evidence to suggest the new strain causes a higher mortality rate or that it affects vaccines and treatments although urgent work is underway to confirm this.”
He told the news briefing: “In the South East, 43% of the virus is now this new variant, in Eastern England it’s 59%, and in London 62%.”
Rates of hospitalisation were higher where the new variant was more prevalent.