Influenza is a highly contagious virus that changes from year to year. The best protection against serious illness, hospitalisation, and complications is the annual flu shot. While many Australians understand the importance of being vaccinated, questions about how often to get the flu shot, and who needs it most remain common.
This guide explains why a flu vaccine is recommended each year, when to have it, and who should prioritise it.
Why You Need a Flu Shot Every Year
Influenza viruses constantly mutate. Each flu season, new strains emerge, and the vaccine is reformulated to provide protection against the most likely circulating types. Even if you had a flu shot last year, you’ll still need one this year.
There are two key reasons for annual flu vaccination:
- Vaccine formulation changes: Each year, the vaccine is updated to match the most common strains.
- Immunity: Protection from the vaccine declines after about 3–4 months.
According to the Australian Department of Health, getting vaccinated every year is the most effective way to reduce your risk of flu-related complications especially for vulnerable individuals like children, the elderly, and those with chronic health issues.
When Should You Get Your Flu Shot?
The ideal time to receive your flu vaccine in Australia is between March and May, before winter begins.
Flu season usually peaks between June and September, and it takes about two weeks after vaccination for your body to develop full immunity. Vaccinating in the early part of the year ensures you’re protected when the virus is at its peak.
If you miss this window, it’s still worth getting vaccinated later in the season especially if influenza is still circulating in your area.
Who Should Get the Flu Vaccine Annually?
The flu vaccine is recommended for everyone aged 6 months and over, but it’s especially important for those most at risk of severe disease, including:
- Adults aged 65 years and over
- Children aged 6 months to under 5 years
- Pregnant women at any stage of pregnancy
- Aboriginal and Torres Strait Islander people
- People with chronic health conditions such as: asthma or lung disease, diabetes, heart disease, has weakened immune systems
Other groups who should get vaccinated include:
- Healthcare workers and aged care staff
- Carers and household contacts of high-risk individuals
- People in high-exposure jobs (e.g., public transport, schools, childcare)
Under the National Immunisation Program (NIP), many of these groups are eligible for a free flu vaccine.
Do Children Need a Flu Shot Every Year?
Yes. Annual flu vaccination is recommended for all children aged 6 months and over.
For children under 9 receiving the flu shot for the first time, two doses are needed, spaced at least four weeks apart. In subsequent years, only one dose is required.
Children are more vulnerable to flu complications like ear infections, pneumonia, and, in rare cases, encephalitis. Annual vaccination helps prevent serious illness.
Are There Special Flu Vaccines for Older Adults?
Yes. People aged 65 years and over are offered an enhanced flu vaccine under the NIP. This version includes an adjuvant, which helps trigger a stronger immune response important as the immune system naturally weakens with age.
The enhanced vaccine has been shown to improve protection against hospitalisation and complications in older adults.
Can You Get the Flu Shot With Other Vaccines?
Yes. The flu vaccine can be safely given at the same time as other vaccines, including:
- COVID-19 boosters
- Pneumococcal vaccine
- Shingles vaccine
According to ATAGI, co-administration is safe and supported by clinical evidence. It also reduces the need for multiple appointments.
Are There Any Side Effects From the Flu Vaccine?
Most people tolerate the flu vaccine well. Side effects are usually mild and short-lived, and may include:
- Redness, swelling, or tenderness at the injection site
- Fatigue or tiredness
- Low-grade fever
- Mild muscle aches or headache
These symptoms usually settle within 24 to 48 hours. They’re a normal part of your body’s immune response, not a sign of infection.
Serious reactions are uncommon, but like with any vaccine or medication, there’s a small risk of an allergic reaction. If you’ve had any past reactions to vaccines, it’s important to let your GP or nurse know beforehand.
Is the Flu Vaccine Safe for Breastfeeding Mothers?
Absolutely. Breastfeeding women can safely receive the flu vaccine. Moreover, they pass protective antibodies to their infants through breast milk, offering additional protection to babies who are too young to be vaccinated themselves.
Is It Too Late to Get a Flu Shot If the Season Has Already Started?
No, it’s not too late. While early vaccination is ideal, getting the flu shot later in the season can still provide valuable protection, especially if the flu virus is still circulating in your community.
How Long Does the Flu Vaccine Provide Protection?
The flu vaccine offers optimal protection for about 3 to 4 months, with immunity beginning approximately two weeks after vaccination. This duration underscores the importance of annual vaccination, especially as flu viruses evolve each season.
Can the Flu Shot Cause Flu-Like Symptoms?
Yes, some people experience mild flu-like symptoms such as a low-grade fever, muscle aches, headache, or fatigue after receiving the vaccine. These are not caused by the flu virus itself—the vaccine does not contain live virus—but are a normal immune response and usually settle within a day or two.
How Long Does It Take for the Flu Vaccine to Work?
It takes about two weeks for your body to develop full protection after the flu shot. That’s why it’s recommended to get vaccinated early in the flu season.
Speak With Your GP About the Flu Vaccine
If you’re unsure whether you’re due for a flu shot or have questions about timing and eligibility, your GP can offer personalised advice based on your age, health conditions, and risk factors.
At Sirona Women’s Health, our GPs provide flu vaccination guidance and care for women of all ages, including during pregnancy. We take the time to understand your individual needs and help you stay protected throughout flu season.
Annual flu vaccination is one of the simplest ways to protect yourself and those around you. By staying up to date, you’re not only reducing your risk of serious illness—you’re also supporting the health of your family and wider community.
Book your flu shot today with Sirona Women’s Health in Brisbane.