Influenza (the flu)


Influenza (or the flu) is a highly contagious, acute viral infection that spreads easily from person to person. Influenza is most often caused by type A or B influenza viruses that infect the upper airways and lungs.

The timing and duration of the flu season in Queensland varies from year to year but generally occurs between May and October, with a peak commonly in August. In tropical areas, the pattern can be more variable and may include clusters outside this period. In 2019, there was a wider distribution of influenza onset in Queensland between March and October, with the peak occurring in August.

Flu is not the same as a common cold or COVID-19, but it can be a serious illness. For some people, such as young children, the elderly, and those with underlying medical conditions, the flu can cause serious complications requiring hospitalisation and can sometimes lead to death.

Signs and Symptoms

Symptoms usually appear 1 to 3 days after becoming infected. People are potentially infectious to others even before they have symptoms.

The symptoms of flu can include:

  • fever
  • sore throat
  • dry cough
  • headache
  • muscle and joint pain
  • tiredness or extreme exhaustion

In the elderly, fever may be absent and the only signs and symptoms of flu may be:

  • confusion
  • shortness of breath
  • worsening of a chronic condition
Runny nose or nasal congestion  


Sneezing RareCommon
Sore throatCommonCommon
Temperatures between 38 °C and 40 °C Sudden onset 
Sudden onset
Mild or moderate
Sometimes intense
Aches and painsCommon
Sometimes intense
Duration: A few days, sometimes longer
Nausea and vomitingCommon in children
Rare in adults
Often accompanied by diarrhoea and abdominal pain in children

Children are more likely to have gastrointestinal symptoms (nausea, vomiting and diarrhoea).


Generally, flu is managed by:

  • resting in bed
  • drinking plenty of fluids (particularly water)
  • taking over-the-counter medication to help relieve symptoms (take as directed in the product information).

Prescription antiviral medications can reduce the length of time symptoms last and help you return to your daily routines earlier. These medications are most effective if they are started within 48 hours of flu symptoms appearing.

See your doctor or call 13 HEALTH (13 43 25 84) if you:

  • are concerned about your symptoms
  • are in a high-risk group and have a cough and or high fever (38 degrees Celsius or more) that is not improving

Flu can spread from person to person by:

  • droplets spreading from an infected person when they cough, sneeze or talk
  • touching surfaces contaminated by infected droplets (including hands, remote controls, phones, keyboards and door handles) and then touching your mouth, nose, or eyes.

People with flu can be infectious to others from 24 hours before symptoms start until a week after the start of symptoms. Children and those who have compromised immune systems can be infectious for longer. Even people with mild flu illness can transmit the infection.


You can reduce the risk of infection by getting vaccinated and practising good hand and respiratory hygiene to protect yourself and others. If you are experiencing flu symptoms, you should:

  • stay home when you are sick (in general, you can be infectious for up to a week after the onset of symptoms)
  • wash your hands regularly with soap and water or use an alcohol-based hand rub
  • wash your hands before touching your eyes, nose, and mouth
  • use a tissue, or the inside of your arm, when you cough and sneeze
  • throw tissues away immediately and wash your hands
  • don't share items such as cigarettes, cups, lipstick, toys, or anything which has come into contact with the mouth or nose
  • stay at least 1 metre away from people who have flu-like symptoms
  • clean frequently touched surfaces regularly, such as mobile phones, keyboards, remote controls, door handles, taps, tables, benches, gym equipment and fridge doors (flu viruses can be removed using household detergent)


Vaccination is the best way to reduce the risk of getting flu. Being vaccinated gives you protection against flu by building immunity to the virus and preventing transmission of the virus to other people.

Vaccination is required annually, as immunity from the vaccine decreases over time and the vaccine can change each year to cover the current virus strains. Vaccination usually takes up to 2 weeks to be effective.

Vaccination is recommended for anyone aged 6 months and older who wishes to protect themselves from influenza and its complications.

The influenza vaccine does not contain live flu viruses and cannot cause the flu. However, some people may experience mild flu-like symptoms for up to 48 hours as their immune system responds to the vaccine. Serious reactions to the vaccine are extremely rare. While some people may experience mild side effects such as pain, swelling, and redness at the injection site, these usually resolve quickly.

Immediate allergic reactions to flu vaccine are extremely rare. People withe egg allergy, including a history of anaphylaxis, can be safely vaccinated with egg-based influenza vaccines.

If you experience any symptoms that concern you, call 13 HEALTH, your doctor, or the immunisation provider.

Please visit the Queensland Health 2023 influenza vaccination guidelines for all of the latest influenza vaccination information including:
  • vaccine strains
  • timing for vaccination
  • eligibility for free seasonal influenza vaccines for at-risk groups
  • dosage and administration.

Where to get vaccinated:

  • your doctor or local immunisation provider
  • community pharmacies
  • some local councils
  • Aboriginal and Torres Strait Islander health/medical services
  • some employers may offer flu vaccinations for their staff.

Flu and COVID-19

Influenza (flu) is not the same illness as COVID-19. There are separate vaccines available to protect individuals against influenza and COVID-19. Influenza vaccines can be co-administered (i.e. on the same day) with the COVID-19 vaccines. For further advice please visit the Australian Technical Advisory Group on Immunisation (ATAGI) website.

Whilst the flu vaccine will not prevent COVID-19, infection it can reduce the severity and spread of flu, which may make a person more susceptible to other respiratory illnesses like coronavirus.

Further information and common questions about COVID-19 and flu vaccines can be found on the Queensland Government website.

For more details regarding vaccines that protect against COVID-19 please visit the Australian Government Department of Health's website

Health outcome

Most people recover from the flu within a week, although a cough and tiredness may persist.

Serious complications of flu occur in a small proportion of people who are infected and include pneumonia, inflammation of the heart muscle and neurologic complications, which can lead to hospitalisation and death. People at highest risk of complications from flu include those with pre-existing medical conditions. However, previously healthy people can also have severe complications.

For young children and the elderly, flu is one of the most common vaccine preventable causes of hospitalisation.

Help and assistance

For more information:

If you are in an emergency situation, call 000