Concerns as ‘mutant’ H3N2 flu strain is putting people in hospital: 11 symptoms to be aware of

The countdown to Christmas is on, meaning that cold and flu season is officially in full swing too – and NHS reports say there was an average of 1,700 patients admitted to hospital with the flu last week (double the amount typically expected).

Experts are warning that a specific ‘mutated’ strain of influenza, dubbed the H3N2 strain, has proved slightly more resistant to the flu jab, which could explain the spike in cases.

Professor Julian Redhead, NHS England’s urgent and emergency care director, said, “Today’s numbers confirm our deepest concerns – the health service is bracing for an unprecedented flu wave this winter. Cases are incredibly high for this time of year and there is no peak in sight yet.”

Everyone’s clicking on…

So, what’s going on with the sudden rise of flu cases and H3N2? What are the specific symptoms to be aware of, and how worried should we really be?

Here, two leading pharmacists (with knowledge on all-things flu) explain.

Why are there so many flu cases all of a sudden?

According to Ayesha Bashir, Prescribing Pharmacist at Chemist4U, it’s thanks in large part to the recent cold snap we’ve all experienced.

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“Every winter we see flu cases climb, but this year they’ve picked up a little earlier and a little faster than expected,” she shares. “This winter’s spike is really down to timing and behaviour. As soon as the weather becomes cold, we all spend more time indoors where viruses spread much more easily.

“If a new strain like H3N2 is circulating alongside the usual ones, that simply adds more opportunity for infection to spread quickly.”

What is the H3N2 virus?

In a nutshell, all viruses mutate and change slightly – they’re sneaky in that way (as we all learned during the pandemic). Just as we start building up some herd immunity towards them, they go and evolve, says Bashir.

“You may have seen reports about a new flu strain being monitored this season, called H3N2. Flu viruses constantly shift and evolve, so it’s not unusual for new strains to develop and be monitored closely,” Bashir notes. “What matters most for the public right now is that the symptoms we’re seeing are exactly the same as with more familiar flu strains, and the way we manage and prevent flu hasn’t changed.

“New strains like H3N2 can sound worrying, but they’re part of how the flu virus behaves every year. The good news is we already know that vaccination, good hygiene, and early symptom management still make a huge difference.”

How worried should we be?

On the whole, it’s nothing to panic about, says Claire Nevinson, Boots Superintendent Pharmacist, who particularly recommends getting a flu jab if you’re pregnant, over 65 or in another high risk category (e.g. someone with a weaker immune system). “Although flu is an unpleasant virus that can make you feel very unwell, most healthy adults and children often get better on their own within a week, though they may have a lingering cough and feel tired for a few more weeks,” she explains.

Nevinson adds, “It is also advised that those that are not considered at risk to consider getting a flu jab to help protect themselves. While the jab doesn’t stop you from getting the flu, your symptoms are likely to be milder and not last as long if you have had a vaccination.”

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What symptoms should we be looking out for?

Both Nevinson and Bashir agree that the symptoms of H3N2 flu are the same as your classic flu (which is to say… not very much at all).

These include:

• A sudden high temperature
• A dry or chesty cough
• Feeling very tired or weak
• Muscle aches and joint pain
• A sore throat, a blocked or runny nose
• A headache

“You may also experience chills, difficulty sleeping, loss of appetite, feeling or being sick, tummy pain or diarrhoea,” adds Nevinson.

Bashir reminds that it is extremely important to seek urgent medical advice if you are “struggling to breathe, have chest pain, or your symptoms are worsening after a few days.

“If you’re ever unsure whether your symptoms are typical or need extra attention, always speak to a GP or pharmacist.”

How can you protect yourself from the flu this winter?

Similar to the advice around staying Covid safe, a lot of it boils down to common sense and good hygiene.

“Flu is spread by germs from coughs and sneezes which can live on hands and surfaces for 24 hours therefore practicing good hygiene is key in helping to avoid illnesses like flu,” says Nevinson. “Regular hand washing with soap and warm water for about 20 seconds and regularly wiping down surfaces can help prevent the spread of flu.”

What you eat can play a big part too – think: colourful veggies packed with vitamin C (like bell peppers), garlic, ginger, vitamin D-rich foods (such as eggs and fatty fish) and good old dark, leafy greens. Sleep, managing stress and partaking in exercise also help to bolster your immune system, leaving it in the best possible position for battling bugs.

If you are unfortunately hit with the flu, the best thing you can do is rest up, ensure you’re staying well hydrated (either with water or a sports drink), take ibuprofen or paracetamol to ease aches and pains, and stay warm and cosy.

This article is not intended to be a substitute for professional medical advice or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

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 Jennifer Savin is Cosmopolitan UK’s multiple award-winning Features Editor, who was crowned Digital Journalist of the Year for her work tackling the issues most important to young women. She regularly covers breaking news, cultural trends, health, the royals and more, using her esteemed connections to access the best experts along the way. She’s grilled everyone from high-profile politicians to A-list celebrities, and has sensitively interviewed hundreds of people about their real life stories. In addition to this, Jennifer is widely known for her own undercover investigations and campaign work, which includes successfully petitioning the government for change around topics like abortion rights and image-based sexual abuse. Jennifer is also a published author, documentary consultant (helping to create BBC’s Deepfake Porn: Could You Be Next?) and a patron for Y.E.S. (a youth services charity). Alongside Cosmopolitan, Jennifer has written for The Times, Women’s Health, ELLE and numerous other publications, appeared on podcasts, and spoken on (and hosted) panels for the Women of the World Festival, the University of Manchester and more. In her spare time, Jennifer is a big fan of lipstick, leopard print and over-ordering at dinner. Follow Jennifer on Instagram, X or LinkedIn.