Consider having the seasonal flu vaccination if travelling in 2025

Australia is about to enter its flu season (June to September) and the 2025 flu vaccine has recently become available.

Assess your personal risk

This is a time when everyone should consider their own circumstances.

• How will a bout of flu impact on me?
• Am I in a risk group for serious flu (under 5 years and over 65 years)?
• Do I have a health issue which might make me more at risk of serious flu (diabetes, asthma, cardiovascular disease, chronic disease etc).
• Am I pregnant?

Learn more about influenza - how it spreads, why it’s different from the common cold and who’s most at risk - on our Influenza disease page.

Protect your plans from disruption

There is also another reason to look at a seasonal flu vaccine - protection from disruption.

• Am I about to do something which might be impacted by an illness (travel, getting married, year 12 at school, about to have major surgery etc).

This isn't just about serious flu. This is about inconvenience or not achieving a desired outcome for hard work. While influenza might be just an annoyance for many (a few days in bed or off work), this isn’t the case with everyone.

The flu shot isn't just about preventing serious illness - it's about protecting your plans and important milestones. Whether you're travelling or preparing for a big life event, flu vaccination can save you weeks of disruption.

YTD influenza notification rates

Influenza notification rates are high for the year to date. More than 53,000 cases have been reported in the last 3 months (to 13 April 2025) with almost 390,000 cases over the past 12 months. This latter number is more than 3 times the average number of annual cases for the years 5 years pre-pandemic (114,449). It is even significant when looking at the annual for the last 5 years (172,752).

Is Australia in for a bad flu season in 2025?

Data from the United States suggests we are in for a significant flu season in 2025. We don’t always follow their trend, but we might still be seeing a post COVID effect which tends to be global.

CDC estimates more than 47 million cases of influenza in the 24/25 season with 610,000 hospitalisations and 26,000 deaths. The hospitalisation rate is the highest since the 2010/11 season. There have been 216 paediatric deaths. This is the highest number of paediatric deaths for a non-pandemic season.

Influenza A has been the most common confirmed diagnosis.

The preliminary data can be viewed at CDC.

What is the flu vaccine?

Only quadrivalent influenza vaccines will be available in Australia for the 2025 season. There are 2 types, egg-based and cell-based. Each has 2 strains of Influenza A (H1N1, H3N2) and 2 strains of B in the vaccine.

Both types of vaccine are available under the National Immunisation Program (NIP). The NIP provides free influenza vaccines to those at most risk of serious disease.

A stronger flu vaccine is available to those 65 years and older. Older individuals may not be as responsive to vaccines as younger people. This is called immune senescence. It is also why diseases like influenza and COVID-19 are more likely to cause serious illness in this age group.

The over 65 years flu vaccine has more of the antigen than the standard vaccines. This should provide a better stimulus for antibody production. The composition is still the same.

Corporate flu programs need to be aware of the difference and make sure the older worker is given the appropriate vaccine.

Influenza vaccines can be administered at the same time as any COVID-19 vaccines.

The flu vaccine is not protective against avian influenza.

Who should receive the flu vaccine?

Everyone, 6 months and over is recommended to get a flu vaccine each year but only 30-35% people are vaccinated. Coverage is much greater in those over 65 years than in the younger age groups.

It is strongly recommended for certain groups to be vaccinated. These groups who will receive it free under the NIP.

How effective are flu vaccines?

The effectiveness varies from year to year. It really depends on how close in structure is the vaccine to the circulating strains. Sometimes it is very close and at other times not so good. It is generally accepted that the effectiveness ranges from 40%-60%. The vaccines work better against the B strains of the virus and the H1N1 of the A strain but not so well for the H3N2 strain. It then depends on the predominant strain for the season to determine whether the vaccine was effective for the season.

A study of the 2019-2020 season (pre-pandemic) in the USA showed that vaccination prevented 7 million influenza-related illness, 3 million clinic visits, 100,000 hospitalisations and 7,000 deaths.

Influenza vaccine and travel.

People often confuse a common cold with flu. “Colds” are due to several viruses which have a similar clinical picture. Colds are common, hence the name “common cold”. They are generally annoying rather than disabling. Fortunately, influenza isn’t common, but it can be very unpleasant. A bout of influenza can last for several days. The symptoms can include fever, chills, dry cough, headaches, and severe fatigue. It is also highly contagious. If you are a member of travelling group, you might be the index case for the group and the start of a holiday from hell. It might also be a particularly important holiday, a honeymoon or a 30th wedding anniversary. It might also be an important business trip. It is always important to consider the flu vaccine if there is something you would prefer not to miss!

The flu vaccine is the first vaccine you should consider in the context of travel. Influenza is the commonest health issue which can be prevented by vaccination.

Flu vaccination should never be considered in an age-based context when travelling. It is true that a person aged 20-40 years is less likely to experience serious illness, hospitalisation, or death but they also have something to miss!