At least a dozen hospitals have declared critical incidents as the rise in flu admissions and respiratory illnesses has led to “exceptionally high demands”.
Health services issue critical incident declarations when their services become so overwhelmed they struggle to deliver critical services, risking patient safety. Hospitals in Birmingham, Cornwall, Hampshire, Liverpool, Northamptonshire and Plymouth are among those affected, after figures reveal the number of people admitted to hospital in England with flu quadrupled last month.
We take a look at what is driving the crisis, and whether the situation is likely to be repeated next winter.
Is flu causing more problems than normal this year?
Data from the UK Health Security Agency (UKHSA) suggests flu levels and hospital admissions are higher than this time last year.
According to the most recent figures, the overall weekly hospital admission rate for influenza increased to 14.09 per 100,000 population in the week ending 29 December 2024, compared with 10.69 per 100,000 the previous week, and 8.72 per 100,000 the week before.
“I don’t think it helped that the flu vaccine was offered later this year, compared to last, for some groups,” said Dr Simon Williams, a behavioural scientist and public health researcher at Swansea University. “However, it is not unprecedented to have a December spike in flu cases: we saw something similar in 2022.”
The 2022-23 season was the first time flu had been widespread since the start of the Covid pandemic, and was associated with 14,500 excess deaths – the highest figure since the 2017-18 season.
Figures from NHS England have revealed there was an average of 4,469 flu patients in hospital in England every day in the last week of December 2024. While lower than the same point in 2022, when the figure reached 5,441, there is no sign yet that they have passed their peak.
Prof Julian Redhead, the NHS national clinical director for urgent and emergency care, said: “These latest figures show the pressure from flu was nowhere near letting up before we headed into the new year, skyrocketing to over 5,000 cases a day in hospital as of the end of last week and rising at a very concerning rate.”
What else is behind the NHS pressures?
Flu is only one component of what some have nicknamed the “quad-demic” affecting hospitals. As Redhead noted, as well as flu there are ongoing pressures from Covid, while respiratory syncytial virus (RSV) and norovirus hospital cases are higher than last year.
The NHS’s national medical director, Prof Sir Stephen Powis, said frontline staff were under “significant pressure” and demand on services showed “no signs of letting up”. “There was an average of one visit every eight seconds to the NHS flu advice page in the past week, and on top of flu hospitals are also seeing continual pressure from Covid, RSV and norovirus cases, as the ‘quad-demic’ continues to increase pressure across services,” he said.
There are also the continuing chronic pressures the NHS is facing, including a lack of available beds.
Sir Andrew Pollard, a professor of paediatric infection and immunity at the University of Oxford, said: “The latest data suggest that the spread of flu in the 2024-25 season is likely to be at its peak around now, which means maximum flu pressure on the NHS is now.”
Is the human metapneumovirus (HMPV) outbreak in China having any impact in the UK?
HMPV was first identified in 2001, and is closely related to RSV. It causes cold-like symptoms and, like other respiratory illnesses, can lead to more serious complications such as pneumonia, particularly in elderly people, young childrenand immunocompromised people. Cases have been surging in northern China, with reports of overcrowding in hospitals, and the country’s centre for disease control has warned people to take precautions with health and hygiene.
In the UK, cases increased by 4.15 percentage points between October and December last year, according to UK Health Security Agency (UKHSA) data, with 4.53 of those visiting GPs with respiratory symptoms testing positive by the end of 2024. However, this is only marginally higher than the level at the start of 2024 and in line with expected seasonal increases.
Who is most affected by flu?
Flu can be particularly serious for older people, the very young and those with underlying medical conditions.
Indeed, while UKHSA data suggests those aged between five and 14 are the most likely to test positive for flu, it is older people who are predominantly treated in hospital with the virus.
According to UKHSA figures, in the most recent week hospital admission rates for flu were highest in those aged 85 years and over, at 88.38 per 100,000 in the trust catchment population, with a rate of 26.1 per 100,000 for children aged up to four years.
What is the situation with flu vaccinations?
One possibility is that a lack of protection from influenza may be contributing to the situation in hospitals.
According to the latest figures from UKHSA for England, influenza vaccine uptake in GP patients up to 15 December 2024 was 37.6% in those aged under 65 years in a clinical risk group, 33.1% in pregnant women, 40.3% in children aged two years, and 41.6% in children aged three years. By contrast the figure was 73.0% in adults over 65 years.
It is difficult to compare uptake across years because the start date for this winter’s vaccination programme for most adults was shifted to the beginning of October to tackle the issue of protection waning over time. UKHSA has said, however, that compared with the equivalent week last season, “vaccine uptake is lower for those aged two years, slightly lower for those aged three years, and higher for pregnant women”.
Despite this, the figures suggest a large number of people deemed at increased risk from flu remain unprotected.
Pollard said: “There are 11 million people over the age of 65 years so that leaves 2.75 million unvaccinated. There is a strong age effect with hospitalisation and so the older adults in this population are more likely to be hospitalised.”
Another potential factor is the effectiveness of the flu vaccine: this can vary from year to year depending on how well the vaccine matches the circulating strain.
Pollard said: “We don’t know the vaccine effectiveness yet for this season as it takes time to collect the information and analyse the data, so that answer will come in several weeks’ time. Vaccination remains the cornerstone of protection for the individual and the NHS.”
What else can people do to protect themselves?
Williams said it was important to reduce close contact with others when symptoms hit, adding other useful actions included wearing a mask in hospitals and investing in an air purifier (Hepa filter), noting a filter may also help reduce the risk of airborne viruses spreading indoors.
Prof Susan Hopkins, the chief medical adviser at UKHSA, also emphasised the importance of limiting contact with others, especially vulnerable people, if symptoms arose.“If you have symptoms and need to leave the house, our advice remains that you should wear a face covering. Washing hands regularly and using and disposing tissues in bins can reduce the spread of respiratory illnesses,” she said.
