The UK has reported 93,045 cases of coronavirus in the latest 24-hour period – a record high for daily infections as the Omicron variant surges across the country.
Another 3,201 new cases of Omicron have been recorded, taking the total number to 14,909 as it becomes the dominant strain in Scotland and London.
There were 1,691 new Omicron cases reported in the UK on Thursday.
But health experts have warned there are likely to be many more Omicron infections in the community – as not everyone gets symptoms, not everyone gets tested, and the variant spreads rapidly.
It comes as half of all adults in the UK have now received a vaccine booster dose after the programme was accelerated in the face of the new strain.
A total of 26.3 million people aged 18 and over have received a vaccine top-up.
The government said the milestone makes the UK’s booster roll out one of the fastest in the world.
On Thursday, the UK announced 88,376 COVID cases, following a previous daily high on Wednesday of 78,610.
This time last week, 58,194 cases were reported.
There have been a further 111 deaths recorded within 28 days of a positive coronavirus test. This time last week the figure was 120.
The daily data also shows another 900 COVID patients have been admitted to hospital, with a total of 6,056 in seven days – a rise of 8.1% on the previous week. Some 7,611 patients are currently being treated, including 875 in ventilation beds.
The UK Health Security Agency said on Friday there were 65 patients in England’s hospitals with Omicron, with the number of deaths from the COVID-19 variant unchanged at one.
According to vaccination data, a record number of booster jabs or third doses were administered on Thursday – 861,306. That takes the total number in the UK to 26,338,651.
There were also 32,677 first doses given on Thursday, along with 42,497 second jabs.
In England, the R number, which measures the rate of infection, has risen to between 1.0 and 1.2, compared with last week when it was estimated at between 0.9 and 1.1.
It means every 10 people infected are likely to pass the disease to between 10 and 12 others.
When the value is above 1, it means the epidemic is thought to be growing.
About one in 60 people in private households in England had COVID in the week to 11 December, the same proportion as the previous week, according to the Office for National Statistics (ONS).
Omicron is thought to be much more transmissible than Delta and new research suggests the new variant largely evades immunity from past coronavirus infection or two vaccine doses.
The study from Imperial College London showed vaccine effectiveness against symptomatic Omicron infection of between 0% and 20% after two jabs, and between 55% and 80% after a booster dose.
Researchers say the risk of reinfection with Omicron is 5.4 times greater than that of Delta, and Omicron has the same severity – but hospital data remains “very limited”.
Boris Johnson has warned Omicron is a “very serious threat – we are seeing a considerable wave coming through”.
He said people have “got to be prepared” and the best thing everybody can do is “get boosted now”.
The prime minister urged people to be cautious and should decide what they want to do in terms of attending Christmas parties.
Mr Johnson added that people need to “budget their risk” but the country is not in the same position as last year of “shutting things down”.
In Scotland, Nicola Sturgeon said 51.4% of COVID cases are now likely to be Omicron, which has become the dominant strain, overtaking Delta.
The R number for Omicron could be above 4 and cases of the virus have increased by more than 40% in the past week, the first minister said during a briefing.