Nearly 750,000 people in England were infected with Covid last week — the highest number since the second wave was still raging in January, official figures show.
The Office for National Statistics' weekly surveillance report estimated that one in 75 people had the virus in the seven days to July 17, the equivalent of 741,700, as the epidemic grew by 28 per cent.
It means Covid is more widespread now than it has been since the last week of January, when there were estimated to be about 850,000 cases.
Unlike previous waves, the epidemic is now largely being driven by infections in younger age groups thanks to the vaccination programme which targeted elderly Britons first.
The ONS report shows that secondary school-aged children and adults under 24 were 14 times more likely to have caught Covid last week than over-70s, and six times more likely than over-50s.
In the North West and North East, two regions hit hardest by the Indian 'Delta' variant, cases fell slightly last week and in the East of England the crisis appears to have levelled off in a promising sign.
It comes after Britain's daily infection numbers dropped yesterday for the first time in two months, with the Department of Health recording 39,906 positive tests - a 17.8 per cent drop on the number last Thursday.
However, experts warned the decline may just be temporary dip ahead of a return to exponential growth because the impact of Freedom Day was not yet being felt in the data.
While cases are continuing to rise across England, the 28 per cent increase in the past week marks a slow down on the previous week, when the epidemic grew by 74 per cent.
This week's estimates were based on tests of 130,000 people in private homes across the country. It does not include tests in hospitals or care homes.
While the North East saw a slight fall in positive tests, it was still the region with the highest proportion of its population catching the virus at 2.58 per cent.
There was a similar theme in the North West, where 1.8 per cent of residents were believed to have had the virus last week.
The ONS estimated 1.1 per cent of people in the East Midlands were Covid positive, followed by around 1 per cent in the West Midlands, London and Yorkshire.
The lowest rates were in the South East (0.4 per cent), South West (0.8 per cent) and the East of England (0.8 per cent).
In Scotland, around one in 80 people are estimated to have had Covid-19 in the week to July 17 – up from one in 90 in the previous week and the highest level since the ONS infection survey began in Scotland at the end of October 2020.
For Wales, the latest estimate is one in 210 people, up from one in 360 in the previous week and the highest level since the week to February 19.
In Northern Ireland the latest estimate is one in 170 people, up from one in 290 and the highest since the week to February 12.
Meanwhile, yesterday's update by the Department of Health also showed that a further 84 people had died within 28 days of testing positive as of Thursday, an increase of a third on last week.
The average number of people dying from the virus each day now stands at 55, which is double the figure earlier this month but still 20 times fewer than at the peak of the second wave.
Latest data shows there were 788 Covid hospital admissions on July 18, a rise of 35 per cent on the previous week. Hospitalisations appear to be doubling roughly every three weeks.
But, like deaths, they are being kept five times lower than the peak in January thanks to the vaccine rollout, which saw another nearly 230,000 doses administered today. It means that in total, 36.6million Britons — the equivalent of 69 per cent of adults — have been fully jabbed and 46.4m have had at least one dose, or 89 per cent.