What are we in for this flu season?

ATAGI advises the flu vaccine should be given to everyone aged over six months.

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Influenza vaccines for the 2024 flu season will be available to order from April, with ATAGI advising to vaccinate as soon as stock is available.

Fluad Quad or Fluzone High-Dose Quadrivalent are still the recommended vaccines for those aged 65 and over, but Flucelvax Quad is now available for use in children aged as young as six months (the previous minimum age was two years).

Children aged six months to less than five years are eligible for NIP funding, as well as adults aged 65 and over, Aboriginal and Torres Strait Islander people, pregnant women, and those with medical conditions that put them at a higher risk.

Chronic liver disease, obesity, trisomy 21 and harmful use of alcohol are not medical conditions which attract NIP funding, despite their known increased risk of complications due to influenza.

ATAGI has advised that this year’s flu shot can be co-administered with the COVID-19 vaccination and other vaccines, but recommended Fluad Quad and recombinant zoster vaccine (Shingrix) be separated by a few days.

Professor Adrian Esterman, epidemiologist and professor of biostatistics at the University of South Australia, told The Medical Republic that despite significantly higher case numbers than this time last year, vaccinating before April was not ATAGI’s recommendation.

“The lab-confirmed influenza case numbers are so far much higher than last year, in fact almost double. However, we are still talking about 9000 cases a month, compared to 60,000-100,000 cases expected in June, so starting vaccination in late April still makes sense,” he said.

He explained that due to the lowered immunity to respiratory diseases caused by the transmission precautions that stemmed from Covid-19, we were now seeing very high transmission.

“During 2020-2022, many people took precautions such as social distancing and mask wearing, and this resulted in very low levels of all respiratory diseases. Most people have dropped these precautions,” he said.

“GPs are now more aware of respiratory infections and more willing to test for them. Don’t forget, all of the reported cases are for lab-confirmed disease, and there are probably many times the reported number in the community.”

Pertussis numbers are huge compared to this time last year and current numbers of RSV so far this year are well up on 2022 and 2023 with a peak expected in June or July.

“RSV only became a notifiable disease in mid-2021, so we are still learning about its pattern. At this stage, it is not possible to say what the epidemic curve is likely to look like,” said Professor Esterman.

Covid numbers are down compared to this time last year, but he reinforced that PCR testing was still important for vulnerable people who could benefit from antivirals.

“Official [covid] numbers are greatly under-reported. However, jurisdictions like SA and the ACT who have continued to report weekly data have been showing a downward trend in new cases, and the ACT is seeing a reduction in hospitalisations,” Professor Esterman told TMR.

“The peak at the beginning of the year was caused by the JN.1 variant which is still dominating around the world. However, a new variant is now being followed called BA.2.87.1 which is also highly mutated. It hasn’t taken off yet, but when it mutates further, it will likely cause the next wave.”

The ATAGI clinical advice can be found here.

The Australian Government early advice for health professionals can be found here.