December 11, 2025

expert reaction to the latest NHS data on the current flu season

Scientists comment on the latest NHS data on the current flu season. 

Prof Ed Hutchinson, Professor of Molecular and Cellular Virology, MRC-University of Glasgow Centre for Virus Research (MRC CVR), said:

General Background:

“In temperate climates influenza is mainly a winter illness, caused by three types of influenza virus – H3N2, H1N1 and influenza B virus. They all continually acquire mutations which mean that our immunity against them goes out of date. At the end of this year’s flu season in the southern hemisphere (i.e. our summer) the H3N2 strain of the virus suddenly acquired seven new mutations. This is a lot more than normal, and it  meant that when the flu season took off in the northern hemisphere we had less protection than normal against the H3N2 component of seasonal flu. Because of this, the flu season in the UK started off more quickly than usual, and cases reached high levels sooner. They are continuing to rise, and it is not yet clear how long this will continue for.

Disease:

“In general H3N2 influenza viruses can cause a bit more disease in the elderly than the other two seasonal influenza viruses, but so far there isn’t any evidence that this season’s H3N2 is more dangerous than it normally would be if you get it. It’s just that there are more cases than normal for this time of year, and the small proportion of people who become very unwell with influenza adds up when there are a lot of cases. Most cases of influenza are something you can recover from at home but they are not pleasant, so it’s to everyone’s benefit to try and avoid catching the disease. Severe illness with influenza can happen to anyone, but it is a particular risk for older adults, the very young, pregnant people and people with underlying conditions. The rapid and early increase in influenza cases means that the severe cases add up, which puts pressure on all parts of the NHS and particularly on hospitals.

Protection:

“Despite the changes to this season’s H3N2 virus, initial data from UKHSA indicate that the influenza vaccine is still effective at preventing severe disease, and we would expect it to reduce the risk of you passing on an infection to vulnerable people around you. It can take up to two weeks for the immune response to a vaccine to become fully effective – this season’s flu will be around for a while yet, and it’s worth getting vaccinated as soon as possible if you’re able to, particularly with Christmas on the way. At-risk groups can get the vaccine for free through the NHS, and everyone else can get it relatively cheaply (usually less than £20) from a pharmacy.

“We also know from the effect of COVID measures that things like masking, social distancing and working from home can have a huge impact on the spread of influenza viruses – the widespread use of these measures actually drove one type of seasonal influenza virus extinct during the COVID years. If you suspect that you are infected and are able to do so then masking, working from home and avoiding vulnerable people can be really helpful in stopping flu spreading further. You can also buy quick home tests to check if you are infected with flu. Regular hand washing and making sure rooms are well ventilated is also likely to help.”

Dr Leon Peto, Consultant in Infectious Diseases and Microbiology, Clinical Coordinator for the RECOVERY trial, Oxford Population Health, said;

“Today’s figures indicate this may be the worst flu season in the UK for over a decade, and finding better ways treat people hospitalised with flu could save many lives as well as reducing health service pressures. 

‘One of the major successes in the UK’s response to COVID-19 was the speed with which research led to improvements in treatment. During the pandemic, tens of thousands of patients took part in trials of COVID-19 treatment, but we do not have similar evidence to guide treatment of flu. We need to make sure that research is built into the NHS response to flu epidemics, and this is the aim of the RECOVERY and REMAP-CAP clinical trials, which are evaluating flu treatments at NHS hospitals across the UK this winter.”

Prof Nicola Lewis, Director of the World Influenza Centre at the Francis Crick Institute, said:

“The current influenza season in the UK started earlier than normal and whilst this is unusual, it is not necessarily worse. It’s impossible to predict whether it will be a longer season or if it will finish earlier than usual, so protection is still important and there is still time to get this year’s flu jab. 

“Influenza viruses continually change genetically, which is why we need to have a flu jab every year to ensure we are protected from the most up to date version of the virus that is circulating each winter.

“The subclade K viruses currently circulating are antigenically a bit different from previous strains, so if you’ve not had this year’s flu jab, you will be more likely to get flu and if you do, you can be more severely ill.”

Prof Shereen Hussein, Professor of Health and Social Care Policy at the London School of Hygiene & Tropical Medicine (LSHTM):

“The rise in flu admissions will understandably be alarming, but the phrase ‘super flu’ risks obscuring what really matters: supporting those most vulnerable, particularly older people and those receiving care at home or in care homes.

“What we learned during COVID-19 is that social care is not a peripheral sector in a health crisis; it is central. Yet it is often absent from headlines and national planning. Our recent NIHR research on care homes shows that infection-control measures, while necessary, can come with very real human costs if implemented without adequate support.

“With flu circulating at unusually high levels, families can take simple but impactful steps: checking in more frequently with older relatives or neighbours, helping them arrange vaccination, and taking precautions such as staying away when unwell or wearing a mask during visits. These actions protect both individuals and the already stretched care workforce.

“This Christmas, safe connection should be the priority. Short but frequent visits, good ventilation, wearing a mask if you have mild symptoms or have been recently unwell, and using phone or video calls if an in-person visit is not safe. We can protect people from infection and from loneliness. Both are essential to health and dignity.

Additional information also attributable to Prof Shereen Hussein:

“Regular check-ins, whether by phone or in person, are one of the most effective ways to protect older people during a winter virus surge. The new WHO global report shows that one in six people worldwide experience loneliness, and this has measurable impacts on physical and mental health. “Maintaining social connection is therefore not an optional extra; it is a core part of keeping people well. Our NIHR research found that when contact is reduced, older people in care homes experienced declines in emotional, cognitive and physical well-being, and staff saw the consequences very clearly. So families and communities play a vital protective role.

“To arrange vaccines for family members or those you support, the most straightforward routes are booking through your GP surgery or a local pharmacy. Many pharmacies offer walk-in appointments. You can help with transport, reminders or waiting with them to reduce anxiety.

“Avoiding hospital where you can may help the stretched workforce, but it is absolutely crucial that no one should delay seeking care because they feel like a burden. If someone has severe breathlessness, chest pain, sudden confusion or is getting markedly worse, that requires urgent assessment.

“Vaccination for flu remains the most effective protection for high-risk groups. Alongside this, the familiar measures still matter. Staying home when unwell, hand and respiratory hygiene, improving ventilation in indoor spaces and wearing a mask in crowded places or when visiting someone vulnerable. These actions are especially important for care homes, where staff already carry significant emotional labour and organisational strain. Our research shows that during crises they act as frontline change agents, often filling gaps left by systemic underfunding and fragmented guidance.

“Care homes have extensive infection-prevention protocols and will be stepping these up, including enhanced cleaning, careful cohorting during outbreaks, ensuring high vaccine uptake among staff and residents, and encouraging symptomatic staff or visitors to stay away. But our research shows that care homes often receive guidance that is late, inconsistent or poorly tailored to the realities of social care settings. Staff are then left to interpret and implement policies without adequate support, which creates moral distress and can undermine both infection control and residents’ experience.

“Loneliness is one of the most significant but least acknowledged health risks facing older adults, especially during periods of heightened infection concern. The WHO Commission report identifies loneliness as a major public health challenge with wide-ranging health impacts, including increased mortality risk.

“Our NIHR research during the pandemic showed how quickly residents’ wellbeing deteriorated when social connections were restricted, and how profoundly this affected both residents and staff, who often felt morally distressed enforcing rules that conflicted with their caregiving values.

“Care homes are also deeply aware of the dangers of social isolation. The WHO global review highlights that social disconnection can degrade health, and our NIHR findings show exactly how damaging prolonged isolation can be for residents’ emotional, cognitive and physical wellbeing.

“Families should expect care homes to balance safety with connection. This includes maintaining visits where possible, supporting digital communication and enabling meaningful contact with appropriate precautions.

“This Christmas, safe connection should be the priority. Short but frequent visits, good ventilation, wearing a mask if you have mild symptoms or have been recently unwell, and using phone or video calls if an in-person visit is not safe. We can protect people from infection and from loneliness. Both are essential to health and dignity.”

Dr Vanessa Tobert, Infectious Diseases Registrar, and Clinical Research Fellow, Oxford Population Health, University of Oxford said:

“The latest influenza statistics indicate that this flu season is very serious, with hospital admissions this week nearly double the rate last week and still rising. Fortunately, although the dominant circulating strain is antigenically diverse to that of the vaccine, the latest data show that vaccination is still providing a good level of protection, preventing hospital attendance at the same rate we would expect in any other year.

“Flu remains a serious illness that causes hospitalisation and death each year. Although this disease has been around for a very long time, we still don’t have good evidence to guide treatment. This season highlights the importance of clinical research; we are currently running the RECOVERY global clinical trial to provide definitive evidence of the best possible treatment for people hospitalised with flu.”

Dr Elizabeth Whittaker, Department of Infectious Disease, Imperial College London, said:

“The flu statistics match what we are seeing in the emergency department and wards in our hospitals, it is very busy. This follows what was seen in Australia in their winter, and importantly, they saw lots of cases in children. The vaccine is a good match this year for protection, so now is the time for pregnant women and those children who missed their dose in school to get one to protect themselves for Christmas.

“The flu vaccine is free and recommended for all children aged between 2 to 17. As always, if a fever in a child doesn’t settle after 5 days, or settles and starts again, the advice is to contact NHS 111 or seek advice from a GP.”

Dr Lindsay Broadbent, Lecturer in Virology, University of Surrey, said:

“Influenza viruses that infect humans are divided into two ‘types’ A and B. Most of the cases we are currently seeing belong to Influenza A, which is further divided into subtypes which are determined by two of the viral proteins haemagglutinin (H) and neuraminidase (N). This is where we get the naming of influenza A viruses such as H1N1 or H3N2. Our influenza season is being dominated by H3N2, which is further categorised into ‘clades’ and ‘subclades’ based on the genetic sequence of the virus. The H3N2 virus we are seeing mostly belong to subclade K.

This information is important, because mutations in certain viral genes may give us information on how likely antiviral treatments are to work or if the vaccine efficacy may be impacted.

The scale and severity of any influenza season result from several driving factors including how the virus has mutated or ‘drifted’ over time, vaccine efficacy and vaccine uptake, and the timing of the beginning of the flu season. It has been a few years since H3N2 was the dominant circulating strain in the UK, the last time was the 2021-2022 flu season. It is possible this has led to waning immunity in the community. We have also seen a very early start to the flu season, meaning a lot of people eligible for the vaccine, and most vulnerable to severe disease, may not yet have been vaccinated (and the vaccine takes about 2 weeks to be effective).

The RSV season is also picking up, we are seeing an increase in RSV cases. A respiratory virus that is particularly dangerous for young babies but can also cause severe disease in older adults or those with underlying conditions such as asthma or COPD.

The increase in both influenza and RSV is worrying for the NHS, that will be under pressure to meet demand.”

Declared interests:

Prof Nicola Lewis: WHO and Worldwide Influenza Centre 

Prof Shereen Hussein: No COIs to declare

Dr Elizabeth Whittaker: “I am one of the lead investigators for REMAP-Cap NIHR funded flu study – see signature below for affiliations and title, I don’t have any specific flu related COI ,but have done trials with Sanofi, Pfizer and Moderna for other treatments/vaccines etc”

Dr Vanessa Tobert: “Research funding provided by Flu Lab”

Dr Lindsay Broadbent: “I receive funding from Merck and Verona Pharma.”

For all other experts, no reply to our request for DOIs was received.