The number of people who have had COVID-19 is as high as one in six in some areas of England, figures have revealed.
The Office for National Statistics (ONS) data published on Tuesday measured coronavirus antibodies in people across the UK.
It found that one in eight people in England had COVID-19 by December last year, a rise from one in 14 in October.
See how many people have been infected in your area in the map below
It estimated that 5.4 million people in England aged 16 and over have previously had a COVID-19 infection.
But the ONS said there were “substantial” differences between the nation’s regions.
While some regions have seen one in six people infected, others are much lower, with only one in 20 catching the virus.
In Yorkshire and the Humber, the worst affected region, 16.8% of the population tested positive for COVID-19 antibodies in December.
This was closely followed by London on 16.4% and the North West – which includes cities such as Manchester and Liverpool – on 15.1%.
Both regions saw significant increases from October, when London’s infection rate was 11%, while it was 6% in the North West.
The West Midlands and the East Midlands had 14.3% and 12.7% respectively in December.
The North East matched the national average of one in eight with 12.5% of people having COVID-19 antibodies.
However, in the South East (8.3%) and the East of England (8.1%) the figure dropped to one in 12.
The area with the lowest level of antibodies among its population was the South West – 4.9% had been infected by December, giving a ratio of one in 20.
Across England, “there is substantial variation in antibody positivity between regions”, the ONS said in its report.
The number of people who test positive for antibodies indicates how many people have previously had the infection.
Experts analysed blood samples from people across the UK for the study.
But they warned that the length of time COVID-19 antibodies are detectable in the blood is not known.
The ONS study measures antibodies in people who live in private households across the UK. It does not include those in hospitals, care homes or other institutional settings.
Virologist Lawrence Young, a professor of molecular oncology at Warwick Medical School, said the results show infection is “much more widespread in the UK than previously realised”.
He said: “The implications are that infection rates increased significantly between November and December.
“This raises some important questions concerning the possible impact of the UK variant virus on infection rates – this variant is more transmissible and may account for the increased levels of infection as detected by antibodies.”
While one in eight people in England are thought to have been infected with COVID-19, the figure for Wales is one in 10.
The ONS said the ratio is one in 11 in Scotland and one in 13 in Northern Ireland, based on its antibodies tests.
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