Covid-19 infections in the UK have risen by 31 per cent in the biggest percentage jump since June, with most of the country now seeing a steady increase in virus levels.
The levels of older age groups catching Covid-19 have also risen and there has been a higher rate of hospital admissions among the elderly.
The figures come as England announced on Friday that people aged 50 and over can now book an appointment to receive a fresh Covid-19 booster vaccine.
About 1.7 million people in private households across the UK are likely to have tested positive for Covid-19 in the period from September 23 to October 3, according to the Office for National Statistics (ONS).
This is up from 1.3 million in the previous survey, which covered the period September 18 to 26.
It is the highest UK-wide total since late July, but is still below weekly infections of 3.8 million in early July, at the peak of the wave caused by the Omicron BA.4/BA.5 sub-variants of the virus.
However, there is a delay in the reporting of the ONS data due to the time it takes for the survey to be compiled.
More recent figures show the number of people in hospital testing positive for Covid-19 is on a clear upwards trend, though there are signs the rate of increase may have slowed in recent days.
“Infections have risen again across much of the United Kingdom, continuing the pattern of steady increases seen over recent weeks, although Scotland and the north-east of England had uncertain trends in the latest week,” Sarah Crofts, ONS deputy director for the Covid-19 infection survey, said.
“We have also seen another notable rise in infections amongst older age groups in England and Wales, underlining once again the need for close monitoring as we move through the colder months.”
In England, the number of people testing positive for Covid-19 in the latest survey was 1.5 million, or about one in 35 people — up from 1.1 million, or one in 50, in the previous survey.
Wales has also seen a rise, where the latest estimate for infections is 74,900, or one in 40 people, up from 63,400, or one in 50.
The trend in Scotland is described by the ONS as “uncertain”, with 109,700 people likely to have Covid-19 in the latest survey, or one in 50, compared with 113,000 in the previous survey, or one in 45.
In Northern Ireland the latest estimate is 45,100 infections, or one in 40, compared with 46,100, which is also one in 40 — though the longer trend there is showing an increase.