What is really happening with the flu this winter?

The flu should always be taken seriously. It is a virus that kills thousands of people every winter and puts a strain on hospitals.

However, I don’t remember a flu season that went like this. Some media outlets and even NHS England have claimed it is both a ‘superflu’ and ‘unprecedented’ – while experts say this year’s flu is not unusual with accusations of ‘crying wolf’.

So, what’s really going on and are things really different this year?

As I reported in early November, some feared the flu season could be the worst in a decade.

Scientists tracking the world’s multitude of flu viruses noticed seven new mutations in one flu strain – a type called H3N2 – in June.

This newly mutated virus quickly became the dominant form of H3N2 and was named subclade-K.

The flu season started a month early in the UK, suggesting the virus could potentially spread more widely than normal and it was too late to adjust this year’s flu vaccine to match the new mutations.

That was the worry, but the reality is more like a normal flu than a super flu.

The influenza K virus has not acquired a spectacular capacity to ravage the population.

“It spread at a very similar speed to previous years, it was towards the higher end, but it was not an outlier,” says Professor Christophe Fraser, who analyzes the spread of the virus at the Pandemic Sciences Institute at the University of Oxford.

His team’s latest analyses, yet to be published, suggest that the mutations have actually given the virus a slight advantage in overcoming our immunity – on the order of 5 to 10% more than usual. It’s unclear whether this applies to everyone or only focuses on children and young adults who have caught the flu less in the past and have been most affected so far.

H3N2 viruses always tend to be more severe in older people, and there is no clear evidence that the virus is worse than expected this year. A rapid analysis of the seasonal flu vaccine also suggested its performance was consistent with previous years, despite fears of a lag.

Dr Jamie Lopez Bernal, consultant epidemiologist at UKHSA, said: “The unusual things we’ve seen this season are the early start to the season, we’ve also seen this change in the virus, with more evolution than we usually see.

“But overall, in terms of the impact on the NHS and the impact on people’s health, we are seeing a largely typical flu season.”

Some suggest that the flu may already be peaking, although this carries great uncertainty. Questions are being asked about what happens at Christmas, when everyone gets together and it’s easier for the virus to infect older people, who are more at risk. There are also signs that another flu strain, H1N1, is spreading in Europe and could lead to an increase in cases here as well.

But a “broadly typical flu season” probably isn’t the impression you’d get from watching or reading the news.

Statistical art was used to compare an early flu season to one that started much later, allowing claims of flu cases to be “10 times higher” than in 2023.

This was technically true, but that’s like saying your train to Glasgow got you there in record time… but the journey time was the same, you just booked an earlier train.

NHS England was not the first organization to start calling the disease superfluous, but Professor Meghana Pandit, national medical director of NHS England, called it an “unprecedented wave of super flu”.

The British Medical Association suggested that the flu had been used for fear-mongering purposes as resident doctors decided whether to continue their strike.

Superfluous is not a scientific description and the BBC health team has not found any experts who think it is accurate.

“I don’t think it’s a useful term, there’s no particularly unusual set of symptoms, there’s no indication that it’s associated with exceptional severity, exceptionally rapid spread or exceptional health impact,” says Professor Fraser.

One of Britain’s top flu scientists, Professor Nicola Lewis, director of the Global Influenza Center at the Francis Crick Institute, said the virus was “not particularly unusual” and that she had seen “no evidence” that the virus was “particularly different” and that superfluous “wouldn’t be my description”.

England’s former deputy chief medical officer during the pandemic, Professor Jonathan Van-Tam, said: “I don’t understand at all what is meant by the rather silly term ‘superflu’.

Persuading people to get a flu shot saves lives and last winter, it was estimated that vaccines saved around 100,000 people from hospitalization.

However, experts have begun to question whether the escalation of language used since the Covid pandemic could damage trust in official health advice. Previous winters have seen warnings of a tripledemia of flu, Covid and RSV; then it was upgraded to a quademic addition of norovirus; this year it’s superfluous.

Dr Simon Williams, a psychology and public health researcher at Swansea University, says there are problems with “the current language that every winter is ‘the worst’ in one way or another” and risks a “cry wolf” effect which damages trust and means people become “unresponsive” to advice.

He said there was a danger of “abusing the narrative that viruses are going to overwhelm the NHS” when “ultimately the NHS has not been overwhelmed to the point of not being able to carry out its emergency and core functions”.

Instead, he argues that a “right balance” is needed between raising awareness and “not falling for fear messages or being too alarmist, which can backfire.”

Professor Jonathan Ball, a virologist at the University of Nottingham, agrees: “I think it’s concerning to use words like super flu, when we might one day have a real super flu.

“We have to be very, very careful in how we communicate these things to the public, because we risk crying wolf.”