The proportion of people, likely to have tested positive for antibodies, has been revealed.
An estimated one in eight people in England would have tested positive for antibodies to Covid-19 by December last year, up from one in 14 in October, new figures show.
Antibody data on infection in private households suggests that one in 10 in Wales had also been infected by December, alongside one in 13 in Northern Ireland and one in 11 in Scotland.
The figures come from the Office for National Statistic’s Covid-19 Infection Survey in partnership with the University of Oxford, University of Manchester, Public Health England and Wellcome Trust.
They are based on the proportion of the population who are likely to have tested positive for antibodies to Covid-19, based on blood test results from a sample of people aged 16 and over, but do not reflect all the people who have had coronavirus and do not take account of antibodies waning over time.
The ONS found “substantial variation” between regions in England, with 17% of people in private households in Yorkshire and the Humber estimated to have tested positive for antibodies in December, compared with 5% in south-west England.
In London, the figure was 16% in December, up from 11% in October, while it was 15% in the North West, up from 6% in October.
In the West Midlands, 14% have had Covid, up from 8% in October, while 8% in the South East and the East of England have had the virus, both up from 5% in October.
The study came as Health Secretary Matt Hancock revealed he is self-isolating after receiving an alert through the NHS Covid-19 app.
In a video posted on Twitter, he said: “Last night I was pinged by the NHS coronavirus app, so that means I’ll be self-isolating at home, not leaving the house at all until Sunday.”
Mr Hancock, who has previously had coronavirus, said self-isolating is important because it is “how we break the chains of transmission”.
Meanwhile, some family doctors continue to express their frustration about the rollout of vaccines across the UK.
The latest figures showed 4,133,720 people in England, Scotland and Wales have received a first dose of vaccine.
With more than half of the over-80s and half of elderly care home residents having received the jab, ministers have now given the go-ahead to begin vaccinating the next priority groups – the over-70s and the clinically extremely vulnerable.
On Monday night, Mr Hancock acknowledged that some parts of the country had made better progress than others in vaccinating those in the top priority group, but said more supplies of the vaccine are being pumped to areas that have fallen behind.
Nevertheless, some GPs have taken to social media saying they are “crying out for more vaccines” and that their elderly patients want to be vaccinated in local surgeries rather than having to travel further afield to mass centres.
The Government believes it is still on track to vaccinate around 15 million high-priority people across the UK by February 15.
Elsewhere, Professor Janet Lord, director of the Institute of Inflammation and Ageing at the University of Birmingham, urged caution among those who have already been vaccinated.
Asked whether people who have received the jab can hug their children, she told BBC Radio 4’s Today programme: “I would certainly advise not to do that at the moment because, as you probably know, with the vaccines they take several weeks before they are maximally effective.
“It’s really important that people stay on their guard even if they’ve had that first vaccination.”
She also warned against the idea of a coronavirus immunity passport until more is known about transmission of the virus among those who have been vaccinated.
However, Professor Julian Savulescu, director of the Oxford Uehiro Centre for Practical Ethics, said those who have proven immunity should not be restrained.
“There’s a serious ethical issue that you’re only entitled to restrict people’s liberty in a liberal society if they represent a threat to other people,” he told the Today programme.
“Carrying a virus is like carrying a loaded gun that can go off accidentally.
“We’re entitled to restrain people and check whether they have a gun, but, if they don’t have a gun, to restrain them, that’s false imprisonment.”
He added that efforts should be made to allow those with “certain immunity” to return to work and normal life.