What is the H3N2 flu strain – and how serious is it?

It’s that time of year again Cough And Cold There are massive outbreaks and everyone seems to be getting sick.

But health experts have warned that this winter could be one of the worst ever The most serious flu outbreak in decades already wreaking havoc NHS,

New H3N2 strain It has been branded “disgusting” by health bosses, who have warned NHS may have to face a tidal wave” Of Disease Ahead of Christmas.

for hospitalization Fever Already up 56 percent compared to the same week last year, experts warn the peak of the season is yet to come. Health chiefs have told Britons wear a face mask outside If they feel unwell and eligible people are encouraged to get them vaccinated,

With increasing cases, Independent Spoke to GP and medical consultant Dr. Giuseppe Aragona for prescription doctor, About how concerned we should be about H3N2 and how to stop it.

What is H3N2 strain?

H3N2 is a type of influenza virus that is recognized as one of two widely circulating strains. Also known as subclade K, it is currently the most dominant strain in England, according to the UK Health Protection Agency (UKHSA).

Dr. Aragona explained that the letters and numbers refer to the surface proteins of the virus, hemagglutinin (H) and neuraminidase (N).

He said this particular combination can sometimes cause more severe disease, especially in older people or those with underlying health conditions.

“H3N2 changes regularly, so the version of the virus circulating this year may differ from previous years or from the seasonal version.” vaccineThat could make people more vulnerable,” he said.

what are the symptoms?

flu symptoms and symptoms According to the UKHSA, it develops very quickly and extreme fatigue is common, which is different from the symptoms of a cold that occur more slowly.

Symptoms and severity of H3N2 illness are similar to those of seasonal flu, including fever, cough, runny nose, and possibly other symptoms such as body aches, vomiting, or diarrhea.

People who are considered at higher risk for developing flu-related complications include: children under five years of age (especially children under two years of age), adults age 65 and older, pregnant women, and people with certain chronic medical conditions such as asthma, diabetes, heart disease, weakened immune systems, and neurological conditions.

How high are flu rates right now?

According to NHS England, 1,717 patients were admitted to hospitals in England with the infection every day last week, a 56 percent increase from the same week last year.

The rates are seven times higher than in 2023, when there was an average of 243 flu patients per day.

It also follows Australia’s biggest flu season in history, which is often seen as an accurate predictor of what the UK can expect.

Why is H3N2 so bad this winter?

Dr. Aragona said there are a few different reasons why the flu is likely to be especially bad this winter.

First, he points out that flu season has started earlier than usual, giving the virus more time to spread.

He said it has also “evolved” from last year’s strain, meaning that previous immunity or even the vaccine may provide less protection than usual.

“Fewer people have been exposed to flu in recent years, especially children, making more people vulnerable to it,” he said. “On top of that, cold weather, indoor mixing and social habits all contribute to rapid transmission, creating a perfect storm for high flu rates.”

Experts previously warned that the strain had evolved seven new mutations over the summer, meaning it is significantly different from previous strains included in this year’s vaccines.

Britain is bracing for flu deaths this winterNHS leaders have issued a “flu jab SOS” urging people to get protected.

According to the UKHSA, there were almost 8,000 deaths from flu last winter. The figure is higher than the nearly 3,500 deaths recorded last year, but lower than during the 2022 to 2023 season, when there were nearly 16,000 deaths.

How can you protect yourself from the flu?

Dr. Aragona said the “most effective” way to protect yourself from H3N2 is to get a flu vaccine — especially if you’re in a “high-risk group” such as over 65, pregnant, the very young, or living with a long-term health condition.

“The vaccine may not prevent every infection, but it significantly reduces the risk of severe disease and hospitalization,” he said.

Dr. Aragona said protection can be improved by maintaining good hand hygiene, covering your mouth and nose when you cough or sneeze, avoiding close contact with sick people and keeping your home well-ventilated.

New data published by the UKHSA this week shows the 2025-2026 vaccine is currently 70 to 75 per cent effective in preventing hospital attendance in children aged two to 17, and 30 to 40 per cent in adults.

Dr. Jamie López Bernal, consultant epidemiologist on vaccination at the UKHSA, said the results provide “reassuring evidence” that seasonal flu vaccines can provide significant protection despite concerns about the new subtype.

He “strongly encouraged” every eligible person to get a flu vaccine “as soon as possible,” calling it the “best defense” against serious illness.

Deputy Chief Medical Officer Dr Thomas White said: “Flu can be an unpleasant infection for many people and can be life-threatening for some; vaccination The best form of prevention.

“Early data from the UKHSA shows that this year’s vaccine is providing good protection against the flu variants spreading this year. Flu season has started early this year. If you are eligible now is the time to get vaccinated.”

Last year’s flu vaccine had a significant impact in reducing severe illness, with about a 40 percent reduction in the number of people age 65 and older who were hospitalized and a 75 percent reduction in the number of people hospitalized.

How concerned should we really be about H3N2?

Dr. Aragona said that although the flu can be “unpleasant” to most healthy adults and children, he cautioned against panic because it is usually “manageable.”

“However, for older people, people with chronic diseases and other vulnerable groups, H3N2 could be serious, and the early onset and stress characteristics of this season may put additional pressure on the health service,” he said.

“The important thing is to remain vigilant: get vaccinated, take appropriate precautions, and seek help immediately if symptoms become severe. With these steps, the risk can be managed effectively, even in a year when the flu is spreading more widely.”