Explainer: free flu jabs: how’s the influenza season tracking?

Australia’s five biggest states have all recently announced free influenza vaccinations for everyone. While flu jabs have always been free for people in vulnerable categories (under five, over 65, pregnant, relevant medical conditions, and/or Aboriginal and/or Torres Strait Islander), now most Australians can skip the price tag for flu immunisation completely – at least until the end of June.

What’s behind the sudden push? Cosmos investigates.

Why are there free influenza vaccinations?

There was a sharp increase in influenza cases across Australia during May. When the borders are open, influenza cases always rise during winter. But the May increase is earlier than normal – the sharpest increases usually happen later in the year, with the peak occurring between July and September.

In addition to this, flu vaccination rates are relatively low. As of 30 May, the Department of Health reported seven million influenza vaccines administered around the country, or just over a quarter of the population. The National Centre of Immunisation Research and Surveillance (NCIRS) reported that in 2020, the last year we anticipated a “normal” flu season (anticipated, but didn’t get one), total immunisations reached 34%.

“Influenza vaccine rates are low, and lower than normal,” says David Heffernan, president of the New South Wales branch of the Pharmacy Guild of Australia.

“And that’s combined with early onset this year, or early outbreak of the influenza virus.”

In 2020 and 2021, COVID-19 quarantine measures meant that there were vanishingly few cases of influenza, and last year flu vaccinations went down in concert with this.

Is the flu more dangerous than usual?

If there’s been no influenza in the country for two years, does the current outbreak pose a higher risk?

“The strains circulating are similar to those in recent years – i.e., influenza A/H1N1 and A/H3N2 – so I wouldn’t expect any major differences in severity,” says Professor Allen Cheng, an infectious disease physician at Monash University and director of the Infection Prevention and Healthcare unit at Alfred Health.

So, there’s no virological reason for the flu to be more severe. What about its infectiousness?

“Transmissibility is a complex interaction between changes in the virus – i.e. mutations causing ‘antigenic drift’ – and the history of what individuals have been exposed to in the past (both infection and vaccines),” says Cheng.

“So we might anticipate that if there hasn’t been much influenza in the last few years, that overall, population immunity might be a bit lower, but there are also lots of other factors that might also influence influenza activity.”

Those other factors – a colder-than-usual La Niña summer, for instance – could also have a role to play in the early infection spike.

Why should I get vaccinated?

Because the influenza virus changes every year, a new vaccine is needed each year to fend off the new strains.

The influenza vaccines contain inactivated versions of the three or four (this year, four) strains of influenza that are thought to be most prevalent. Getting vaccinated won’t necessarily stop you from catching flu, particularly a different strain, but it is likely to lower your chances of infection and hospitalisation.

It also helps to protect people who are more vulnerable to the flu – particularly people younger than five years of age or older than 65.

“Influenza vaccination is probably only going to have a partial effect – it probably only reduces influenza infection by about 40% to 50%,” says Cheng.

“So even if everyone got vaccinated, influenza would probably still circulate.

“This doesn’t mean it isn’t useful – we once calculated that without influenza vaccination there would be twice as many hospitalisations, and if coverage were increased, 8% to 20% of hospitalisations could be avoided.”

There are eight different flu vaccines being used in Australia this year, some of which have been grown in eggs, and some of which have been grown in cell cultures.

Over-65s are eligible for an enhanced vaccine that, in addition to the four inactivated strains, has an adjuvant, a substance that provokes the immune system into reacting more strongly.

Will there be a shortage of flu shots?

Many of us remember waiting months for our first COVID vaccines last year. If flu vaccines are suddenly free for nearly everyone, are we going to have enough?

“I don’t know how there could be any supply issues, especially with the announcement on Friday of the TGA (Therapeutic Goods Administration) releasing 16.8 million doses of influenza vaccine,” says Heffernan.

“They approved those doses. Once approved, they are ready to dispatch.”

Once dispatched, Heffernan says, flu vaccinations can make it to most distributors within a day (remote parts of the country can take a few more days).

Given seven million people have already been immunised this year, that additional 17 million brings us very close to the country’s population of 25.9 million.

“The only limiting factors I can see at the moment will be, of course, the simple logistical factor – you can’t shunt everyone through the door at once – and the other limiting factor will be workforce,” says Heffernan.

“The health sector has been running at capacity for two years now, ever since the COVID emergence, and with community pharmacies participating in delivering the COVID vaccine, and also the influenza vaccine, that does tend to soak up a lot of workforce.”

Staff shortages from COVID-19 play a limiting role in this as well.

“We’ve been working at capacity. And I know that a lot of pharmacists are struggling to man their pharmacies,” says Heffernan.

This means that, while you might not find a free booking tomorrow, you should be able to get a flu jab this month.

“We expect initial high demand,” says Heffernan.

“Phones will be running hot, booking systems will be full. And people may not be able to get in for a couple of weeks. But we ask the public to be patient.”

Pharmacies, and other providers, have also been asked to give preference to people in vulnerable groups.

“Every time we have a quickly implemented policy, there will always be warts on it,” says Heffernan.

“There will always be little speed humps we have to iron out. But nevertheless, we’re well conditioned after the COVID pandemic and I think community pharmacies are a good place to take this load.”

Decided to get your shot but can’t get a booking this week? In the meantime, there are a number of (likely very familiar) things you can do to avoid getting or spreading flu.

“Interventions that work for COVID (masks, working from home, avoiding others when unwell) are also probably quite effective for influenza, so the same messages apply for both,” says Cheng.