A record 4.9 million people in the UK are estimated to have had Covid-19 in the week ending March 26 — up from 4.3 million in the previous week, the Office for National Statistics said.
Covid-19 infections increased in England and Wales, but the trend was “uncertain” in Scotland and Northern Ireland, said officials.
The ONS figures were released as free testing ended in England.
Figures also showed which professions were most and least likely to be vaccinated.
Kara Steel, a senior ONS statistician, said the “rapid rise” is being fuelled by the growth of the Omicron BA.2 variant across the UK.
“Infection levels remain high, with the highest levels recorded in our survey seen in England and Wales and notable increases among older age groups,” she said.
In England, about one in 13 people — 4.1 million people — were likely to test positive for Covid-19 last week. This is up from one in 16, or 3.5 million people, in the week to March 19, the ONS figures show.
In Wales, the estimate is up from 192,900 people, or one in 16, to 212,000 people, or one in 14.
Both England and Wales are now recording record infection levels.
Scotland and Northern Ireland had numbers slightly below their recent record infection levels but the ONS would only describe the latest trend as “uncertain”.
For the age groups, 35 to 49, 50 to 69 and 70 and over, infections are at record levels.
Professor Tim Spector, from King's College London, said the timing of the end of free testing “couldn't really be worse” .
He said England was now in a situation of “having to rely on the public to actually do the right thing and get these tests themselves when they get sick”.
Separate figures from the UK Health Security Agency show the number of reinfections is continuing to grow, with an estimated 8,717 people in England having had the virus three times, and 74 having had four episodes of infection.
A separate ONS survey released on Friday looked at vaccination levels across the economy.
Scaffolders, beauticians, complementary medicine practitioners and bricklayers are still among the occupations likely to have the highest levels of non-vaccination against Covid-19 — though rates have improved for bar staff and call centre workers.
One in five scaffolders and riggers in England have not received any doses of vaccine, along with the same proportion of complementary medicine professionals and just under 19 per cent of roofers and tilers, new figures suggest.
The same occupations topped a similar list of rates of non-vaccination at the end of last year and levels have improved only slightly since then.
Health professionals — just under 85 per cent ― and teaching and other educational professionals — almost 84 per cent ― were the most vaccinated sectors.