More than a million people in England are currently infected with coronavirus, the prime minister has said.
Boris Johnson was speaking at a Downing Street news conference on the first full day of the nation's third lockdown, as the Office for National Statistics (ONS) said one in 50 people in England have COVID-19.
Chief medical officer Professor Chris Whitty said it was "really quite a large number indeed" and warned the new variant is "taking off" in areas outside London and the South East.
Numbers of people with coronavirus in private households between 27 December and 2 January, according to the ONS:
- London - around one in 30
- Southeast England - around one in 45
- Eastern England - around one in 45
- Northwest England - around one in 45
- East Midlands - around one in 50
- Northeast England - around one in 60
- West Midlands - around one in 65
- Yorkshire and the Humber - around one in 65
It comes as another 60,916 people in the UK tested positive for COVID-19 in the latest 24 hour period - the first time the daily number has exceeded 60,000.
However, mass testing was not taking place during the first peak of the pandemic so it is unclear how many cases were circulating then.
There have also been another 830 coronavirus-related deaths in the UK, government figures show. It means that a total of 76,305 people have now died within 28 days of a positive COVID-19 test.
Professor Whitty said coronavirus hospitalisations across England are "rising very rapidly and, of course, we are still in the middle of winter".
He told the news conference that the fastest increase of the new variant is in the East of England, London and the South East, but it is "now taking off in other areas as well".
He warned the risk is "extraordinarily high" if people do not take the stay at home message seriously, owing to the new variant as well as winter.
Professor Whitty said the risk level will gradually decrease over time with measures being "lifted by degrees, possibly at different rates in different parts of the country, we'll have to see".
Giving an update on coronavirus vaccinations, Mr Johnson said 1.1 million people in England have had a jab, with a total of 1.3 million across the UK.
At least 650,000 people aged over 80 - 23% of all over-80s in England - have been vaccinated so far.
The government has said the NHS is working "24/7" to ensure 13 million people in the most at-risk groups are offered a vaccine by the middle of next month.
The prime minister said: "By February 15th, the NHS is committed to offering a vaccination to everyone in the top four priority groups including older care home residents and staff, everyone over 70, all frontline NHS and care staff and all those who are clinically extremely vulnerable.
"And to help us with meeting this target we already have 595 GP-led sites providing vaccines, with a further 180 coming on stream later this week. We have 107 hospital sites - with a further 100 later this week."
Mr Johnson added: "Next week we will also have seven vaccination centres opening in places such as sports stadia and exhibition centres."
The latest shutdown to try to control the spread of COVID-19 was announced yesterday.
The prime minister said he believes that by the middle of February there will be a prospect of relaxing some of the measures - but he warned there are "lots of caveats built into this".
He said he had "no choice" but to plunge England into a third national lockdown, and vowed to use "every second" under the stringent restrictions to put an "invisible shield" around the elderly and vulnerable through the mass vaccination programme.
Earlier, Cabinet Office minister Michael Gove told Sky News the government "should be able" to begin easing England's coronavirus lockdown in March.
He said the public should not expect a sudden relaxation of the COVID-19 rules, with restrictions "progressively" eased instead.
Analysis: For the PM and the nation, everything now rests on the vaccine's success
By Jon Craig, chief political correspondent
The prime minister will be relieved he wasn't challenged too much on the boffins' alarming new figures that more than a million - one in 50 - people are now infected.
Yes, that's right: A million infected and one in 50 of us with the virus.
Those frightening figures, at the start of lockdown three, are eye-watering compared with those in lockdown one, back in March.
No wonder the prime minister wanted to talk about the vaccine.
For Boris Johnson and the nation, everything now rests on the vaccine's success and how swiftly it can be administered.
"The jabs are going into people's arms day by day," he declared optimistically at the end of this news conference.
But he'll face more and more questions about the vaccine programme as long as lockdown three lasts.
And he'll also be hoping there are no more lockdown sequels.
