One in 16 people in England has tested positive for Covid in the latest week of data, according to the Office for National Statistics (ONS).
The latest ONS figures show infections are increasing across England, Wales and Scotland, but have gone down in Northern Ireland.
The rise in cases is driven by the Omicron BA.2 variant - a mutation of the Omicron variant that ripped through the country over the Christmas period.
In England, around one in 16 people in private households are estimated to have had the virus in the week ending on March 19 - compared to one in 20 people in the week ending on March 12.
In Wales, the estimate is up from one in 25 to one in 16.
Scotland has seen infection levels rise for eight weeks in a row and they have now reached a new record high, with around one in 11 people testing positive for the virus - up from one in 14 the previous week.
Meanwhile, Northern Ireland has recorded its second successive weekly fall.
The latest figures say in the week ending on March 19 that one in 17 people tested positive for Covid compared to one in 14 in the week prior.
It comes as elderly people in hospital with Covid-19 is seeing the biggest surge for 12 months as infections rates soar.
The hospitalisation rate for over-85s stood at 178.3 per 100,000 people last week, up from 137.0 the previous week.
For those aged 75 to 84 it was 74.3, up from 59.8.
UK Health Security Agency (UKHSA) said rates in both age groups now at their highest since mid-January 2021 at the peak of the second wave.
New infections are increasing in all age groups and in all regions and King’s College London today yesterday estimated an R-value for the UK of 1.2.
It comes as staff absences at NHS hospitals in England due to Covid-19 jumped more than 30 per cent week-on-week, the biggest increase of 2022.
Dr Susan Hopkins, UKHSA chief medical adviser, said the figures were “a reminder to us all that the pandemic is not over”.
Professor Adrian Esterman, an epidemiologist and biostatistician, says the Omicron BA.2 variant is up to six times more transmissible than the original strain of Covid - and we can expect most people to catch it.
While it is less deadly, BA.2 is a mutation of the Omicron variant of coronavirus and now accounts for the majority of new infections in the UK.
BA.2's R number, the rate at which it can spread, is 12, compared to 2.5 for the original virus.
Prof Esterman told MailOnline this level of infectiousness makes the new strain "pretty close to measles, the most contagious disease we know about".
