Will a new mutated flu strain cause a rough winter?

The flu hits us every winter, but something seems different this year.

A seasonal flu virus suddenly mutated in the summer; it seems to bypass some of our immunity; It started the flu season more than a month earlier and is a strain of flu that history suggests is more severe.

The NHS has now issued a ‘flu vaccine SOS’ as fears grow that this will lead to a brutal winter.

There are many nuances and uncertainties, but leading flu experts told me they wouldn’t be shocked if this was the worst flu season in a decade.

“We haven’t seen a virus like this for some time, these dynamics are unusual,” says Prof Nicola Lewis, director of the World Influenza Center at the Francis Crick Institute.

“This definitely interests me,” he says. “I’m not panicking, but I’m worried.”

So what’s going on? So what can we do?

Scientists track the evolution of flu viruses because viruses are constantly mutating, and the seasonal flu vaccine must be updated every year to keep up.

This evolution occurs in a rhythm known as “change and drift.”

Most of the time the virus drifts by making small changes and then there is often a sudden sudden change as the virus mutates significantly.

This happened in June this year.

Seven mutations have emerged in the H3N2 seasonal flu strain, leading to a “rapid increase” in reports of mutated viruses, says Prof Derek Smith, director of the center for pathogen evolution at the University of Cambridge.

Unusually, this event occurred in mid-summer in the northern hemisphere, outside flu season.

“It’s almost certainly going to sweep the world, so from that perspective it’s something that’s going to come out quickly,” says Prof Smith.

By September, there was an increase in cases as children returned to school, the nights progressed, and temperatures began to drop.

Exactly what the mutations do is still being studied, but they likely help the virus evade part of the immune system we’ve built up over the years through flu infections and vaccines.

As a result, the virus makes it easier to infect and spread to people; this is why flu season starts so early in the UK and other countries, including Japan.

If the virus can spread more easily, it won’t have to wait for more favorable winter conditions (when we spend more time indoors with the heating on and windows closed) to kick off the flu season.

“We are miles ahead,” says Prof Lewis, “I think it will be a strong flu season.”

If you remember your R numbers in the pandemic (that’s the number of people each infected person passes the virus on to), it shows that the new mutant has an advantage.

Prof Lewis said the R number for seasonal flu was usually around 1.2 but the initial estimate for this year was 1.4.

So roughly, if 100 people had the flu, this number would increase to 120 in a normal year and 140 this year.

“There will most likely be a bad flu season and it will happen very soon, we are already in it,” says Professor Christophe Fraser from the Institute of Pandemic Sciences at the University of Oxford.

“There are indications that this could be worse than some flu seasons we’ve seen in the last 10 years.”

During a typical flu season, about one in five people become infected, but this year that figure could be higher, he warns.

But all these predictions are still clouded by uncertainty.

Some are looking to Australia for clues as it has had its worst flu season on record this year, although it is not facing the mutated H3N2 that we have.

We know that the virus spreads very well in children at the germ fest that is the school playground.

But the immunity a 10-year-old develops will be very different from that of their grandparents, whose immune defenses have been honed by six times more flu seasons.

Therefore, experts will closely monitor whether the virus begins to infect older age groups in the coming weeks.

History shows that the flu we are facing this year is particularly severe for older people.

There is more than one strain of flu, and you may have heard of names like H1N1 swine flu, which caused a pandemic in 2009, or H5N1, the current flu that is killing birds worldwide.

The new mutations occurred in an H3N2 influenza group.

“H3 is always a warmer virus, a worse virus, more effective on the population,” Prof Lewis said.

It is worth remembering that some of us will catch the flu and show no symptoms, while others will experience sudden fever, body aches and fatigue, but the virus can be fatal in older and more vulnerable groups.

Nearly 8,000 people died from the flu last year, with nearly 16,000 deaths in the 2022-23 flu season. The NHS is already expecting a tough flu season.

So what can we do about this?

The obvious advice is to get the seasonal flu vaccine; The NHS in England has issued a “flu vaccine SOS” stating that there are 2.4 million vaccine slots available next week.

Prof Lewis said this was “absolutely the most important year” to get vaccinated and “If you have been called by your GP please get your flu vaccine as soon as possible.”

However, this year’s vaccine is not a perfect match with the mutated virus.

The decision on the design of the vaccine was made in February to allow sufficient time to produce the millions of doses required, and the new mutant subsequently emerged in June.

“Some protection is better than no protection, but this year is likely to be one of those years where the amount of protection is less than in years where compliance is better, which is not an ideal situation,” Prof Fraser said.

The vaccine will still trigger the body to produce antibodies that can recognize and stick to the flu.

But the biggest benefit is expected to be reducing the severity of the disease, rather than stopping you from getting sick or slowing the spread of the virus.

In the meantime, advice has been sent to doctors reminding them that: early antiviral treatment It reduces the risk of complications from flu.

Japan is also going through an early flu season and has closed schools to help control outbreaks.

These are not Covid-style lockdowns, but short-term measures the country is using to prevent the spread of the virus.

No one knows for sure what will happen in the coming months.

“This could all be gone by next week,” says Prof Lewis. “But I don’t think it will.”