Influenza (more commonly known as the flu) is caused by a highly contagious virus that usually spreads through coughing and sneezing. Symptoms of flu include fever, muscular pain, headache, sore throat and cough. Symptoms may persist for days or more. 

Influenza can cause serious illness, and the sufferer can become so unwell they are unable to attend work or take care of their family members.  Some people even require hospitalisation. Healthcare workers also risk spreading the disease to vulnerable patients.

An annual influenza vaccine is recommended for everyone aged six months and over, including healthy adults. Yearly vaccination is important because: 

• Flu strains change each year 
• Immunity from the vaccine decreases over time 
• The vaccine is updated annually to provide the best protection against circulating strains 
• Protection generally develops within 2–3 weeks and lasts around 6–12 months.

If you have questions or concerns about vaccination, speak with your healthcare provider.

All flu vaccines currently available in Australia are safe to use.  All vaccines in Australia must pass stringent safety testing before being approved for use by the TGA. 

You are more likely to experience a serious complication from a disease, rather than from the vaccine for that disease.

It is not uncommon to experience minor side effects after a vaccination, such as pain and redness at the injection site. Most side effects only last a couple of days and you will recover without any problems.

Most common side effects are a sign that your body is starting to build immunity (protection) against a disease.

Serious side effects from vaccines are extremely rare. If you have questions or concerns about a reaction to a vaccine, talk with your healthcare provider.

If you have any concerns post vaccination, please speak with your GP or in a serious event, present to the Emergency Department. 

The influenza vaccine is recommended for pregnant women and those planning to be pregnant. It is the best way to protect your newborn baby against influenza and complications that can harm developing babies. 

By getting vaccinated, you pass on protective antibodies to your baby through the placenta, protecting them in their first few months of life when babies are most vulnerable and too young to receive the influenza vaccines themselves. 

Speak with your GP, midwife or obstetrician if you have any questions or concerns. More information on vaccination in pregnancy is available from the Immunisation Program Nurses in the ATAGI Australian Immunisation Handbook.

No. The vaccine does not contain live virus and contains only inactivated virus particles (a virus that has been concentrated, killed, then broken apart).  It is therefore incapable of causing influenza infection.

Protection from the vaccine (seroprotection) is generally obtained within 2 - 3 weeks. The duration of post-vaccinal immunity varies and is usually 6 - 12 months.

The influenza vaccine is an inactivated (dead) vaccine. It cannot give you the 'flu' and is generally well tolerated. However, side effects can occur.

• Common side effects can include occasional discomfort, redness and swelling at the injection site. 
• Infrequent side effects include headache, fever, muscle pain and malaise. This can occur within a few hours of vaccination and may last 1 - 2 days. 
• Rare side effects include immediate adverse events such as hives, swelling of the face, lips and tongue, breathing difficulties such as wheezing or systemic anaphylaxis. 

Post vaccination: if you have any concerns post vaccination, please speak to your local GP or attend your local emergency department.

Influvac 

Each 0.5 mL dose of Influvac contains the following three types of influenza virus strains:

• A/Missouri/11/2025 (H1N1)pdm09 like virus
• A/Singapore/GP20238/2024 (H3N2) like virus
• B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Inactive ingredients: Potassium chloride, monobasic potassium phosphate, dibasic sodium phosphate dihydrate, sodium chloride, calcium chloride dihydrate, magnesium chloride hexahydrate, water for injections

Potential allergens: egg protein (ovalbumin or chicken proteins), formaldehyde, cetrimonium bromide, sodium citrate, sucrose, gentamicin sulfate, traces of tylosine tartrate, hydrocortisone, and polysorbate 80

Useful Links:

NPS MedicineWise – Consumer information

The Australian Immunisation Handbook – Influenza (flu)

 2026 seasonal influenza ATAGI statement 

Fluad