Australia’s flu season is yet to peak, but United States health authorities are already looking for signs of what might be in store for their own winter.

CNN reports scientists in the US typically look to Australia and some other countries to try to anticipate exactly how bad the American flu season will get at the other end of the year.

“We closely monitor what happens in countries throughout the southern hemisphere this time of year, just to see what’s happening during their flu season,” said Carrie Reed, chief of epidemiology and prevention at the Influenza Division of the US Centres for Disease Control and Prevention.

“It’s not always a predictor of what’s going to happen here the next season, but … we do closely monitor that all summer long.”

But experts told TND what happens during Australia’s flu season, which is expected to peak about late July, isn’t likely to directly correlate with what will happen when it’s the northern hemisphere’s turn.

This is especially true given the US is at a different stage post-COVID than Australia, Monash University associate professor in epidemiological modelling James Trauer said.

“The US are in a pretty different position because they didn’t really do what we did and skip two full years of flu, because they didn’t have the elimination approach to COVID that we had,” he said.

“It’s basically only [countries like] Australia, New Zealand and China that held everything right down to zero for two full years, and then you can expect to get a rebound and some unusual patterns as a consequence of that.

“But the US really didn’t go down that track, [so] I don’t think there’s as much reason to think that things will be unpredictable next winter in the US.”

However, he said there is value in keeping an eye on international flu seasons ahead of time to observe what strains of influenza are circulating most, and target the season’s vaccines accordingly.

So far, so normal

Ian Barr, deputy director at the World Health Organisation Collaborating Centre for Reference and Research on Influenza, said Australia’s flu season is tracking “reasonably normal” so far.

Influenza A (H1), a strain that puts young children at higher risk, accounts for the majority of this year’s local flu cases.

This is a change from last flu season, when Influenza A (H3) – a strain that puts the elderly at greater risk – reigned supreme.

“These are cyclical events; often we will cycle through the different viruses, with one predominating or the other,” Professor Barr said.

Low vaccination rates

The flu is largely considered a regular part of life, but it can still have severe consequences.

From January 1 to May 28, the Department of Health and Aged Care received 57,816 notifications of laboratory-confirmed influenza, of which more than 17,000 were diagnosed in the last fortnight of May.

Since January, there have been 57 deaths associated with influenza, and since seasonal surveillance began in April, there have been 518 hospital admissions with confirmed influenza.

Professor Barr said these are relatively normal figures for this time of year, but low vaccination rates are concerning, both overseas and in Australia.

“Only 30 per cent of people have been vaccinated this year, so that’s relatively low,” he said.

“Last year, by the time the season finished, which is not the best time to get vaccinated, we got up to 43.4 per cent. So we’re well below that.

“It seems to be hard to get people motivated to be vaccinated – we need a bit of retraining.”