Influenza (flu) – immunisation

Influenza immunisation provides protection against influenza and helps reduce the number of infections and deaths. Good hand hygiene, cough etiquette and staying home when unwell also help prevent the spread of influenza.

Influenza (flu) is caused by a highly contagious virus that is spread by contact with fluids from coughs and sneezes. Every year, the flu causes widespread illness in the community.

During 2024, continued seasonal flu activity and COVID-19 are anticipated.

Vaccination is key to protecting yourself and those around you from the flu.

Who should be immunised against the flu?

Immunisation against the flu is recommended for everyone aged 6 months and over.

Some people with underlying medical conditions or reduced immunity are more at risk of complications from the flu and are eligible for the free flu vaccine under the National Immunisation Program (NIP). They include:

• Aboriginal and Torres Strait Islander people aged 6 months and over
• Children aged 6 months to under 5 years
• Pregnant women at any stage of pregnancy
• People aged 65 years or over
• People aged 6 months or over who have medical conditions that mean they have a higher risk of getting serious disease:
  • cardiac disease
  • chronic respiratory conditions
  • immunocompromising conditions
  • haematological disorders
  • chronic metabolic disorder
  • chronic kidney disease
  • chronic neurological condition
  • long term aspirin therapy in children aged 5 to 10 years.

Speak to your immunisation provider to see if you are eligible for a free flu vaccine.

People not eligible for free flu vaccination under the NIP can purchase the flu vaccine from their immunisation provider.

Where to get the flu vaccine

In Victoria the most common way people access the flu vaccine is from their doctor (GP) or a pharmacist immuniser (a service fee may apply). Some local council immunisation services also provide the flu vaccine as do some hospitals, maternity services and community health services.

Workplaces seeking to reduce the impact of flu infection on employees may also provide flu vaccination programs for their staff.

When to get the flu vaccine

Yearly vaccination before the onset of each flu season is recommended. In most parts of Australia, flu season occurs from June to September, with the flu vaccine typically available from April.

Recent evidence suggests optimal protection against the flu occurs within the first 3-4 months following vaccination. It is important to note that, while the influenza virus continues to circulate, it is never too late to vaccinate.

How the flu vaccine works

Flu viruses change every year because the flu virus has a unique ability to change its surface structure. This means that even if you had the flu or an immunisation one year, your body’s immune system might be unable to fight the changed version of the virus that will be circulating the following year.

Each year, a new vaccine is developed (usually called the seasonal flu vaccine) and is available for those who wish to be immunised. The seasonal flu vaccine includes protection against four strains of influenza viruses.

The flu vaccine cannot give you the flu because it does not contain live virus. Some people may still contract the flu because the vaccine may not always protect against all strains of the influenza virus circulating in the community.

Flu vaccines for different ages

Age restrictions apply to all flu vaccine brands. There are formulations for people under 65 years and a formulation for people 65 years and older. For adults aged 65 years and over, the Fluad® Quad brand and formulation is preferentially recommended over standard influenza vaccines.

Check with your immunisation provider that the right formulation is used for your age or someone in your care.

Children aged 6 months to less than 5 years

Children aged 6 months to less than 5 years are at higher risk of complications from the flu. Even healthy children can become seriously ill from the flu.

The flu vaccine is recommended and funded under the NIP for all children aged 6 months to less than 5 years and can be given at the same time as childhood vaccines.

Refer to the consumer fact sheet for further information.

Pregnancy and flu immunisation

Pregnant women are at increased risk of complications from the flu. The flu vaccine is strongly recommended in each pregnancy and is safe for pregnant women to receive at any time during pregnancy. It can also be safely given while breastfeeding.

The flu vaccine can be safely given at the same time as the whooping cough (pertussis) vaccine (between 20 and 32 weeks) and/ or COVID-19 vaccine during pregnancy.

Flu vaccination of pregnant women also protects infants against the flu for the first 6 months after birth due to transplacental transfer of antibodies from the vaccinated woman to the unborn baby.

Some people may need more than one flu vaccine each year

There are some people who are recommended to have a second dose of the flu vaccine within the space of one year.

These include:

• Children less than 9 years receiving their flu vaccine for the first time require 2 doses 4 weeks apart for an adequate immune response.
• People who have had a haematopoietic stem cell transplant or solid organ transplant and are receiving the flu vaccine for the first time after transplant.
• Pregnant women who received an influenza vaccine in 2023, are recommended to receive the 2024 vaccine if available before the end of pregnancy.
• Women who receive an influenza vaccine before becoming pregnant; revaccination during pregnancy maximises protection of the mother and infant in the first six months of life.
• Overseas travellers, who may benefit from a second dose of this season’s flu vaccine if going to the northern hemisphere winter and receiving the northern hemisphere formulation there is not feasible.

Please check with your immunisation provider to find out whether you fall into one of these categories.

Can you have the flu vaccine and other vaccines on the same day?

Yes. The flu vaccine can be co-administered (that is, given on the same day, one after the other) with other vaccines. This includes whooping cough, respiratory syncytial virus (RSV), pneumococcal and COVID-19 vaccines.

Speak to your immunisation provider for advice about COVID-19 and flu vaccines for children aged 6 months to less than 5 years.

For information about COVID-19 vaccines please visit COVID-19 vaccination.

The flu vaccine pre-immunisation checklist

Before receiving the flu vaccine, your immunisation provider will go through a pre-immunisation checklist with you. Make sure that you tell them if you (or your child):

• are unwell (have a temperature over 38.5°C)
• have had a serious reaction to any vaccine
• have had a severe allergy to anything
• are under 6 months
• have had Guillain-Barré syndrome.

Possible side effects of the flu vaccine

The flu vaccine can cause side effects. In children under 5 years, these reactions may be more obvious.

Common side effects of the flu vaccine include:

• drowsiness or tiredness
• muscle aches
• localised pain, redness and swelling at the injection site
• occasionally, an injection-site lump (nodule) that may last many weeks but needs no treatment
• low-grade temperature (fever).

Managing side effects after immunisation

Common side effects following immunisation are usually mild and temporary (occurring in the first 2 days after vaccination). Specific treatment is not usually required. There are several treatment options that can reduce the side effects of the vaccine including:

• Drinking extra fluids and not overdressing if there is a fever.
• Although routine use of paracetamol after vaccination is not recommended, if pain and fever are present, paracetamol can be given – check the label for the correct dose or speak with your pharmacist (especially when giving paracetamol to children).

Concerns about side effects

If the side effects following immunisation are unexpected, persistent, or severe, or if you are worried about yourself or your child’s condition after a vaccination, see your doctor or immunisation nurse as soon as possible or go directly to a hospital.

Immunisation side effects may be reported to SAEFVIC, the central vaccine reporting service in Victoria on 1300 882 924 (option 1).

You can discuss how to report problems in other states or territories with your immunisation provider.

Rare side effects of the flu vaccine

There is a very small risk of a serious allergic reaction (anaphylaxis) to any vaccine. This is why you are advised to stay at the clinic, medical surgery, or pharmacy for at least 15 minutes following vaccination in case further treatment is required.

Apart from anaphylaxis, other extremely rare side effects include febrile convulsions in children.

A small increase in Guillain-Barré syndrome was seen in the US in 1976, but since that time, surveillance has shown that it is limited to one case for every million doses of the flu vaccine, if at all.

If any other reactions are severe and persistent, or if you are worried, contact your doctor for further information.

Where to get help

• In an emergency, always call triple zero (000)
• Your GP (doctor)
• Emergency department of your nearest hospital
• Your local government immunisation service – visit Find Your Council
• Maternal and Child Health Line (24 hours) Tel. 132 229
• NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
• Immunisation Unit, Department of Health, Victorian Government Email: immunisation@health.vic.gov.au
• National Immunisation Information Line Tel. 1800 671 811
• Your community pharmacy
• Victorian vaccine safety service (SAEFVIC) Tel. 1300 882 924 (option 1)