Prime Minister Boris Johnson is due to give an update on the Covid booster programme at 20:00 GMT.
Image source, EPA
The UK’s coronavirus alert level has been raised from level three to four due to the spread of Omicron, the UK’s chief medical officers have said.
The last time the UK was at level four was in May.
Prime Minister Boris Johnson is due to make a televised statement on Covid at 20:00 GMT on Sunday.
He is expected to provide an update on the booster programme. The BBC has been told there will not be any more new rules announced.
On Sunday evening, the chief medical officers for England, Scotland, Wales and Northern Ireland said they were recommending the coronavirus alert level is raised from level three to level four, which signifies Covid is spreading fast.
Risk levels are measured by a five-level, colour-coded alert system. Level four means a high or rising level of transmission.
The alert level system is separate and independent from any government decisions on easing or tightening rules.
In their statement, the chief medical officers said early evidence shows the Omicron variant is spreading much faster than Delta – and that vaccine protection against symptomatic disease from Omicron is reduced.
“Data on severity will become clearer over the coming weeks but hospitalisations from Omicron are already occurring and these are likely to increase rapidly.
“The NHS is currently under pressure mainly driven by non-Covid pressures. With a variant spreading with increased transmissibility and reduced vaccine effectiveness, we are likely to see this pressure rise soon.”
The UK was last at level four from late February to May this year, and has been at level three since then.
It is not yet known exactly how well vaccines work against Omicron.
But early data shows that getting a third booster dose prevents around 75% of people getting any Covid symptoms from the variant.
The chief medical officers urged everyone to get vaccinated as well as a booster jab – and said people should keep rooms ventilated, wear masks, take regular tests and self-isolate when symptomatic.
Over-30s in England and Scotland will be able to book their booster jabs from Monday – and those in Scotland aged 18 to 29 from later in the week.
More than half a million booster jabs and third doses were given in the UK on Saturday – the second day that has happened since the booster rollout began.
People are now in hospital with Omicron, the government’s Education Secretary Nadhim Zahawi said earlier on Sunday.
Asked whether he could guarantee that all schools would be open in January, Mr Zahawi said he would do “everything in my power” but stopped short of giving a guarantee.
Scientists have said that without more restrictions, the UK is facing a substantial wave of Omicron in January – and the number of deaths from the variant by April could range 25,000 to 75,000 depending on how well vaccines perform.