The upcoming 2023 flu season in Australia – what will happen?

It is always difficult to speculate in advance about the intensity of influenza seasons, as influenza seasons vary greatly from season to season. There’s a saying from those people who work in the field that “If you’ve seen a flu season, then you’ve just seen a flu season” – which means you can’t be too confident just by observing what that happened the previous season. This is even true when looking at the most recent Northern Hemisphere season, which is now coming to an end with the start of March.

Coinciding with the end of their season, the World Health Organization (WHO) recently made a recommendation for the components of the next Northern Hemisphere Influenza vaccines 2023-2024.

The reason these recommendations should be made approximately 8-10 months before flu season is due to the lead time in manufacturing and deploying vaccines in time.

Of interest in this 2023-2024 decision was the change of the A(H1N1)pdm09 component of the vaccine to a reference virus called A/Victoria/4897/2022. This means that all influenza vaccines produced for the 2023-2024 season will contain a derivative of this virus or a similar “similar” virus. This virus was originally obtained from a clinical specimen provided by the pathology laboratory at the Royal Melbourne Hospital and isolated at the WHO Collaborating Center for Influenza Reference and Research at the Doherty Institute.

So let’s go back to what our flu season could present us in Australia in 2023.

One thing is certain, there will be a flu season, unlike 2020 and 2021 when COVID-19 and its many restrictions severely affected the circulation of the flu. In 2022, the flu came back in force and will circulate again widely in 2023.

The start of the season is uncertain. Before the pandemic, cases typically increased through May, peaked in August, and then declined in October. But this schedule may be changed due to COVID-19. In addition, given the difficulty of predicting the severity of the season, it is again recommended that certain people get vaccinated every year, especially the elderly, children under 5, pregnant women, natives and people with underlying health conditions.

So if you want to protect yourself against the flu this year, even if you don’t belong to one of these groups, consider getting your flu shot in 2023.