The number of people in hospital in England who have tested positive for Covid-19 has climbed above 10,000 for the first time since April, as the latest wave of infections continues to gather pace.
A total of 10,658 patients were in hospital as of 8am on July 4, up 36% week on week, NHS England figures show.
The wave is being driven by the newer variants Omicron BA.4 and BA.5, which are more transmissible than other strains and are able to evade the immune protection built up by vaccines or previous infections.
There is “currently no evidence” that BA.4 and BA.5 cause more serious illness than older variants of the virus, according to the UK Health Security Agency (UKHSA).
This means the numbers of people dying from Covid-19 or needing treatment in intensive care are unlikely to reach the sort of levels seen during the first year of the pandemic.
But the growing prevalence of the virus is expected to lead to extra pressure on hospitals, which are already facing a record backlog of patients needing treatment, besides causing widespread workforce absences and disruption across the UK.
The 10,658 hospital patients in England who currently have Covid-19 is nearly two thirds of the peak of 16,600 reached during the Omicron BA.2 wave earlier this year.
UKHSA chief executive Dame Jenny Harries has warned it is “quite likely” the number will peak even higher in the next few weeks, as the majority of infections in the country are now BA.4 and BA.5.
Speaking to the BBC’s Sunday Morning programme, she said BA.5 is “really pushing and driving” the current wave and “it doesn’t look as though that wave has finished yet, so we would anticipate that hospital cases will rise.”
She added that the jump in infections “matters on a national basis”, as an increase in hospital occupancy affects “our ability to treat other illnesses as well”.
Around six in 10 people who test positive for Covid-19 are in hospital to receive treatment primarily for something else rather than the virus, but still need to be kept isolated from other patients, putting extra strain on hospital resources.
The last time the number of patients was above 10,000 was more than two months ago, on April 28.
The highest ever number of people in hospital in England with coronavirus was 34,336, recorded in January last year.
A total of 2.3 million people in private households in the UK had Covid-19 in the week to June 24, up 32% from a week earlier, according to the latest estimates from the Office for National Statistics (ONS).
This is already higher than the 1.3 million infections reached at the peak of both the Alpha wave in January 2021 and the Delta wave in October 2021.
It is still some way below the record 4.9 million infections recorded at the peak of the Omicron BA.2 wave at the end of March, however.
Lawrence Young, virologist and professor of molecular oncology at the University of Warwick, described the latest rise in infections as “really worrying” and a “wake-up call about our vulnerability to new variants”.
Where other countries have experienced significant waves of BA.4 and BA.5, such as Portugal and South Africa, the waves “peaked without a major increase in severe disease, principally due to the levels of vaccination in these populations,” Professor Young continued.
“The hope is that this will be similar here. But this wave does provide a warning for what we could experience over the autumn and winter.”
It is too soon to see any impact on infection numbers from recent large events such as the Glastonbury Festival, Wimbledon or the Hyde Park music festival.
Hospital numbers are continuing to rise in other parts of the UK, with Wales recording 575 patients with Covid-19 on June 30, up 53% from the previous week.
Scotland has seen patients jump 34% week on week, reaching 1,298 on June 26.
The trend in Northern Ireland is uncertain, with numbers rising through most of June before levelling off in recent days at around 400.
Saffron Cordery, interim chief executive of NHS Providers, said hospital trust leaders “know they are in for a bumpy ride over the coming months as they tackle new and unpredictable variants of Covid-19 alongside grappling with seasonal flu pressures which may hit us earlier than usual this year”.
She added: “The policy of living with Covid does not mean Covid has gone away. The latest data shows we cannot afford to be complacent with currently small but concerning increases over the past week in the number of patients both being admitted to hospital with Covid-19 and those needing a ventilator.”
NHS Providers is the membership organisation for NHS hospital, mental health, community and ambulance services.
Take-up of the Covid-19 vaccine could be an additional factor in the latest wave.
Around one in six people aged 75 and over have not received a dose within the past six months, putting them more at risk of severe disease.
All over-75s in the UK have been offered a “spring booster”, available at least three months after their most recent jab, to ensure they continue to receive the maximum possible protection.