Around one in 10 people in the North West of England had Covid last week, data showed, while infection levels rose among people aged 50 and over.
According to Office for National Statistics figures based on swabs taken from randomly selected households, the Omicron wave continued to sweep across the UK.
Infection levels appear to have peaked in London, falling from one in 10 at the end of 2021 to one in 15 in the week ending January 6, but have risen in all other parts of England, except for the east. The northwest recorded the highest levels.
The ONS estimated that 3,735,000 people – or around 1 in 15 – in England had Covid during the week, while the figure for Scotland, Wales and Northern Ireland was around one in 20.
The study also finds that although there was no clear increase in infection levels among those under 50, the percentage of positive tests for Covid remained highest among older adolescents and young adults, to about one in 10 of those in grade 12 by age 34.
There has been an increase, however, among people aged 50 and over who test positive, to around one in 20 of people aged 50 to 69 and one in 30 of people aged 70. This compares to around one in 25 and one in 45 respectively the previous week.
The increase in older age groups is of particular concern given that age is a more serious risk factor for Covid. Vaccination coverage in these age groups has been high, but many received their boosters early, meaning their immunity may since have waned to some extent. Therefore, the impact that high levels of infection may have on older people and, therefore, on health services remains uncertain.
According to official case data – which is based on infections among those who chose to get tested – the number of new cases per day is falling in the UK, with 109,133 new cases reported on Wednesday, compared to one more. from 218,000 earlier in the month.