Experts fear that Australia’s deadly flu season – which killed 57 people, compared with 27 last year – could pave the way for trouble in Britain this winter.

Unpredictable mutations in the virus occur so rapidly that vaccinations against the killer illness become outdated within a matter of years.

More than two-and-a-half times more cases were reported in Australia this year than last as one expert refused to rule out the possibility of Britain being struck by a lethal outbreak.

“We could have another big flu pandemic next year – or we might never live to see it,” Dr Derek Gatherer exclusively told Daily Star Online.

“It could occur beyond our lifetime or it could occur fairly quickly. It’s just not predictable.

FLU SEASON: Experts have warned another pandemic could be on the horizon

“When that next flu pandemic does come, the question is how severe is it going to be?

“Some are very severe, as in 1918. The one in 1957 also killed about three million people.

“The one in 1968 killed about 1.5 to two million people.

“The one in 2009 – the swine flu pandemic, as it was called – was relatively mild compared to the others. About half a million people died in that one.

ARMS RACE: Scientists face an uphill battle to ensure vaccinations stay ahead of the virus

“It was definitely small compared to the other three pandemics that we’ve had in the last 100 years or so.

“There’s the issue of we don’t know when it’s going to occur – and we don’t know how severe it’s going to be.”

The good news this year is, despite a sharp increase in the number of recorded cases, the virus does not appear to have become any more deadly than usual.

“It wasn’t worse but it was more common in Australia and New Zealand,” Dr Gatherer added.

NEVER FEAR: Dr Gatherer claimed advances in medicine would help battle future pandemics

In the event of a pandemic, such as the 2009 swine flu outbreak, scientists are now able to study the virus with increased scrutiny, thanks to continuing advances in medicine.

As a result, Dr Gatherer added, authorities could be better equipped to deal with future pandemics, making outbreaks that kill millions a thing of the past.

“It [2009] was the first time we’d been able to apply our modern molecular laboratory techniques so it was the first pandemic we’d been able to follow in the lab,” he explained.

“We were able to get an idea of how the genome was changing during the course of the epidemic which wasn’t possible previously in the 1960s or the 1950s.”

Derek Gatherer, a lecturer at Lancaster University (Faculty of Health and Medicine), is the lead educator on Influenza: How the Flu Spreads and Evolves, available on the FutureLearn social learning platform.