Covid-19 hospital admissions in England are at their highest rate since the end of April, in a fresh sign the virus is likely to be circulating more widely among the population, figures show.
It comes as the latest round of Covid booster vaccinations gets under way, with residents in care homes for the elderly among the first to receive their jabs this week.
The rollout has been brought forward as a precaution against the latest Omicron subvariant of Covid-19, BA.2.86, which was first identified in the UK on August 18.
But it is still too early to assess the impact of the new strain, with scientists saying they need more data before drawing “firm conclusions”.
Hospital admissions of patients who tested positive for Covid-19 stood at 4.6 per 100,000 people in the week to September 10, up from 3.7 per 100,000 the previous week and the highest since the week ending April 30, according to the UK Health Security Agency (UKHSA).
This is still some way below the level reached at Christmas 2022, when the rate stood at 11.8 per 100,000, and is also well below the figures seen during the first year of the pandemic.
The rate has been on a clear upwards trend for the past two months, however.
Rates remain highest among people aged 85 and over, at 51.1 per 100,000, and 75 to 84-year-olds, at 21.2.
Covid-19 booster jabs will be offered to everyone in the UK aged 65 and over in the next few weeks.
The number of people in hospital in England who have tested positive for the virus is also continuing to rise, at 3,356 as of September 10, up 15% week on week from 2,915 and the highest since May 19.
The total reached nearly 10,000 during last winter and more than 30,000 in the winter of 2020/21.
Not enough data has been collected around the world to make a reliable assessment of how BA.2.86 might be spreading, the UKHSA said.
Just 37 cases of BA.2.86 in England have been identified in laboratories so far, 28 of which have been linked to an outbreak in a care home in Norfolk at the end of August.
Seven of the 37 were admitted to hospital and no deaths due to Covid-19 have been reported.
A further five BA.2.86 cases have been identified in Scotland, while there have been no cases detected in Wales or Northern Ireland.
Dr Renu Bindra, UKHSA incident director, said that while BA.2.86 has a “significant number of mutations” compared with other variants circulating among the population, the data so far is “too limited to draw firm conclusions” about the impact this will have on the severity of the virus.
She added: “It is clear that there is some degree of widespread community transmission, both in the UK and globally, and we are working to ascertain the full extent of this.
“In the meantime, it remains vital that all those eligible come forward to receive their autumn vaccine as soon as it is offered to them.”
There are no longer any official estimates of the prevalence of Covid-19 among the UK population, meaning it is impossible to get a full and reliable picture of the spread of the virus.
Testing for Covid-19 has also been scaled back sharply, so there is not as much data available for analysis.
In the absence of more comprehensive figures, the number of people in hospital with coronavirus can offer a guide to changes in the level of Covid-19 in circulation.