Britain hit by "superflu": record hospitalizations and hospitals under pressure.

In the United Kingdom, a flu wave is mounting, week after week, and has already exceeded levels considered "normal" for this time of year. The numbers speak for themselves: in England, last week, an average of 2.660 patients were hospitalized per day with flu diagnoses, compared to 1.717 the previous week. This represents an increase of approximately 55% in just seven days, equivalent to having "three hospitals full of flu patients alone," as NHS England points out. This is the highest figure ever recorded at this stage of the winter season since statistics began. And what worries experts most is that the seasonal peak has not yet been reached: the epidemic still has considerable room for growth.

The most serious challenge since the Covid pandemic

The definition chosen by British Health Minister Wes Streeting leaves no room for doubt: the "superflu" represents the most difficult challenge faced by the public healthcare system since the 2020 Covid pandemic. In an article in the Times, Streeting warned that the National Health Service (NHS) is in an "incredibly precarious" condition and that a further stressor, such as the five-day strike by specialist doctors scheduled for December 17, could be the "Jenga piece" that could bring the entire tower topple. The image is deliberately drastic: like a board game, removing the wrong piece is enough for the already shaky structure to collapse. Hence the minister's direct appeal to young doctors to accept the new contract offer and suspend their mobilization, just as the pressure of flu-related hospitalizations continues to rise.

The K virus profile: the “super influenza” subclade

At the heart of this wave is a particular influenza strain: the A/H3N2 J.2.4.1 virus, also known as subclade K and dubbed "super flu" by the media. According to the World Health Organization, this virus has been "rapidly increasing" since August 2025 and has been identified in several countries through genetic sequencing analyses. WHO experts emphasize that subclade K viruses exhibit significant genetic differences from the more well-known A H3N2 strains that circulated in previous years. This is a normal evolution of influenza viruses, which continually change over time, but in this case, the accumulated mutations appear to give the virus a greater ability to spread rapidly throughout the population. The good news, at least so far, is that epidemiological data do not indicate an increase in clinical severity: the disease does not appear more severe than the usual seasonal flu, despite being more contagious and capable of affecting a greater number of people more quickly.

Children and adolescents on the front lines of infections

One of the most alarming aspects of the current British outbreak is the age group most affected. Data collected in England shows a particularly marked impact among children and young people between the ages of 5 and 14, in a country where the free flu vaccine is primarily reserved for the elderly and most vulnerable. Schools, as often happens with respiratory viruses, remain a key driver of transmission: crowded classrooms, close contact, low use of masks, and low vaccination rates among young people create an ideal breeding ground for the virus. For this very reason, British health authorities are stressing the need not to underestimate even symptoms considered "trivial" in children, because any additional infection among schoolchildren can trigger a chain reaction that quickly spreads to families and, especially, the elderly.

Schools undergoing sanitization and targeted closures

The pressure of influenza is clearly impacting the education system. Some schools have revived measures that seemed to be a thing of the pandemic past. In Leeds, hand sanitizer stations have been reintroduced in key areas of school buildings in an effort to limit the spread of the virus among students and staff. In Caerphilly, Wales, a school was forced to temporarily close due to a high number of absences due to illness. The Department for Education reiterated that school closures should remain a solution "only in extreme circumstances," recognizing the impact that disrupted learning has had, and could continue to have, on students' learning, social interaction, and well-being.

London, the epicenter of a crisis that was announced

The British capital is one of the areas hardest hit by this flu wave. Chris Streather, head of London's health service, describes the incidence as "unprecedented," while specifying that the situation is not comparable to the pandemic outbreak of 2020. The memory of those months, however, remains vivid: in London, the delay in introducing the lockdown contributed to the deaths of thousands of people in just a few weeks. It is also in light of that experience that London health workers are now issuing very clear appeals: those experiencing flu-like symptoms—cough, fever, runny nose, general malaise—are advised to stay home, avoid public transportation, and, if necessary, skip Christmas parties and gatherings. Streather's advice is explicit: skipping a party if you cough or sneeze is a responsible gesture, not only towards the most vulnerable, but also towards a healthcare system already stretched to its limits.

NHS under pressure: full wards and strikes looming

While English hospitals are facing a record number of flu-related hospitalizations, the threat of a five-day strike by medical residents looms, just as the epidemic threatens to peak. According to NHS data, the current flu bed occupancy rate is already "worst-case scenario," the kind typically expected in the dead of winter, not the weeks leading up to Christmas. Staff are working flat out, often around the clock, to ensure care and continuity of services. In this context, any reduction in medical staff could transform a critical situation into a full-blown emergency. It is the combination of the epidemic and union tensions that has led to talk of a "risk of collapse" for the system.

Flu vaccine: protection against severe cases confirmed

Amid this complex landscape, the flu vaccine remains the main ally in limiting the damage. The WHO, based on initial estimates, emphasizes that seasonal vaccines continue to offer good protection against the risk of hospitalization, both in children and adults, although their effectiveness in preventing clinical illness—that is, symptomatic influenza—this season is still being evaluated. This is a crucial point: preventing every cold or fever is impossible, but significantly reducing severe illness and complications leading to hospitalization remains an achievable goal, thanks to vaccination. It's no coincidence that Chris Streather points out that over 1,8 million people have already been vaccinated this season, but he emphasizes that many vulnerable people have not yet received the vaccine and urges them to "step up as soon as possible." The message is simple: it's never too late to protect yourself, especially if you belong to vulnerable groups or work in contact with the public.

A variant that (partially) escapes previous immunity

Further complicating the situation is the issue of "immune escape," the virus's ability to partially bypass immune defenses built up by past infections or vaccinations. Infectious disease specialist Matteo Bassetti, director of the DIAR infectious diseases unit in Liguria, emphasizes that the H3N2 subclade K tends to escape the protection afforded by strains that circulated in previous years. In other words, those who were vaccinated or had H3N2 influenza last year are not automatically protected against this new variant. Confirming the virus's dangerousness, Bassetti recounts four serious cases hospitalized in his department, all unvaccinated patients: two in their twenties with pericarditis and myocarditis, and two over-eighties with pneumonia. The flu, the infectious disease specialist points out, is anything but trivial: it affects many organs, from the heart to the brain, from the liver to the lungs, and can cause serious consequences even in young, healthy people.

Italy alert, but not alarmed: the outlook for the 2025–2026 season

While hospitals in the UK are already stretched to the limit, in Italy the situation remains under control for now. According to the latest RespiVirNet surveillance bulletin for the week of November 24–30, 2025, the national incidence of acute respiratory infections is 10,4 cases per thousand patients: a significant level, but far from the rate observed in the United Kingdom. There are currently no waves of hospitalizations comparable to those in England, although health professionals urge everyone to remain vigilant. The recommendations are the same: get vaccinated, especially if you are elderly, have chronic conditions, or are immunocompromised, and adopt common-sense behaviors—stay home if you have a fever, ventilate your rooms, wash your hands frequently, and consider wearing a mask in crowded places.

Lessons from the British case: between prevention and collective responsibility

The experience the United Kingdom has been going through in recent weeks offers several lessons for other European countries. The first concerns prevention: with a more contagious virus, the vaccination coverage threshold needed to avoid overwhelming hospitals must be higher. Protecting only the elderly isn't enough if schools become enormous amplifiers of contagion. The second concerns individual behavior: staying home with a fever, skipping an evening out when experiencing respiratory symptoms, and wearing a mask on public transport during peak periods are no longer extraordinary actions, but rather forms of collective responsibility.

Finally, the definition of "super flu" needs to be scaled back, rather than downplayed. This is not a new "monster" comparable to Covid-19, but rather the evolution of seasonal influenza viruses that have found a favorable environment for spread: a combination of genetic mutations, waning population immunity, incomplete vaccination coverage, and social behaviors returning to full normality. In this context, the combination of vaccines, epidemiological surveillance, clear communication, and individual responsibility remains the most effective weapon to prevent the next wave, whether called "super flu" or not, from truly bringing European healthcare systems to their knees.