Influenza (the flu)

  • Influenza, commonly called the flu, is an infection caused by a strain (version) of the influenza virus. It mainly affects the nose, throat and lungs, although it can involve other parts of the body. In healthy children it is much like a bad cold; however, influenza can cause more serious illness, especially in very young children and those with chronic medical conditions.

    Influenza occurs mainly during the winter months. Each year infections are caused by slightly different strains of the virus. Occasionally one of these strains can cause a more widespread or severe outbreak (e.g. H1N1 swine-flu outbreak in 2009).

    Signs and symptoms of influenza

    Influenza usually begins with a sudden fever and at least two of the following symptoms:

    • aches and pains
    • headache
    • cough or noisy breathing
    • sore throat and runny nose
    • low energy
    • nausea, vomiting and/or diarrhoea.

    When to see a doctor

    If you think your child has influenza, you should see a GP who may want to do a test to confirm if your child has influenza.

    Antibiotics are not helpful for influenza because antibiotics do not treat viruses. Your child will only be prescribed antibiotics if they are suspected to also have a bacterial infection. 

    Influenza can be more serious in children with chronic (long-lasting) medical conditions, including:

    • chronic respiratory conditions (including asthma)
    • chronic heart disease
    • chronic neurological or metabolic conditions
    • chronic kidney or liver problems
    • diabetes mellitus.

    It can also be more serious in children who are immunocompromised (have a weakened immune system because of medicines or illness). If your child has any of these conditions and they show signs of influenza, see your doctor.

    Antiviral medications (such as Tamiflu) are sometimes given to children with chronic medical conditions or who have developed severe symptoms. These medicines are not given to otherwise fit and healthy children who have influenza, because the medicines do not usually make a difference to the duration of the illness. They also have little effect if given more than 48 hours into the illness.

    Care at home

    Most children recover from influenza within seven days without any treatment. Ensure your child has plenty of bed rest, encourage them to drink lots of fluids and use paracetamol or ibuprofen for pain or discomfort. See our fact sheet Pain relief for children.  Do not give aspirin to your child, as this can lead to serious side effects.

    If your child becomes more unwell or is showing signs of dehydration or is having difficulty breathing, you should go back to the GP urgently. Some children may need to be admitted to hospital.

    How is influenza spread?

    Influenza is very infectious. It can spread through the air by coughing and sneezing, and by touching objects that have been in contact with saliva or mucus from an infected person. A person with influenza is contagious from the day before symptoms begin until a few days after.

    Good hygiene reduces the chance of getting influenza or passing it to others. Good hygiene includes:

    • regularly washing hands thoroughly
    • not sharing cups or cutlery
    • encouraging children to cough or sneeze into their elbow
    • using tissues instead of hankies – teach your child to throw tissues into the bin as soon as they have used them and to wash their hands afterwards.

    If your child has influenza, keep them home from child care, kindergarten or school until they are well again.

      Influenza vaccine (the flu-shot)

      The influenza vaccine is the most effective way to reduce the chance of your child becoming sick with influenza. The influenza vaccine is recommended annually for everyone aged six months and over.

      If your child has a chronic medical condition, it is strongly recommended that they have an annual influenza vaccination. All household members should also be vaccinated to reduce the chances of your child being exposed to influenza. 

      Because the influenza virus mutates (changes) slightly from year to year, your child will need a new and updated influenza vaccine at the beginning of each influenza season. Two doses are often required in the first year of vaccination for children aged under nine.

      The flu vaccine is free for children aged six months to five years, Aboriginal and Torres Strait Islander people, pregnant people, people aged 65 years and older, and people with medical conditions (such as chronic heart or lung disease, low immunity or diabetes).

      Side effects of the vaccine include pain and redness at the site of injection. Less commonly, children may develop a fever or aches and pains, which last one to two days. The vaccine cannot cause influenza as it contains inactivated (killed) influenza virus.

      While the current influenza vaccines are made using small traces of egg proteins, extensive research shows influenza vaccines are safe for children with egg allergy or egg anaphylaxis. All children will be observed for 15 minutes following the vaccination.

      Key points to remember

      • Vaccination is the best way to prevent influenza.
      • Influenza is very infectious so good hygiene is important.
      • Influenza is caused by a virus so antibiotics cannot be used to treat it.
      • Contact your GP urgently if your child has influenza and becomes more unwell, or shows signs of dehydration or breathing difficulties. 

      For more information

      Common questions our doctors are asked

      What natural remedies can I give my child to help them feel better?  

      We do not recommend giving treatments – whether medical or natural – to children without professional medical advice. Vitamins are not necessary for making your child get better more quickly.

      Is the flu shot safe? 

      All vaccines currently available in Australia must pass stringent safety testing before being approved for use by the Therapeutic Goods Administration (TGA). Because the vaccine contains an inactivated form of the virus, it cannot cause influenza. It can, however, cause milder symptoms that may resemble the common cold.

      I’ve heard of lots of people catching the flu even though they’d had the vaccine. Does the vaccine work?  

      A new influenza vaccination is developed for the beginning of each flu season (most commonly in the winter months). Some years the vaccination is more effective than others, depending on the way the influenza virus has mutated. Some new strains of the virus may not be covered by the vaccination. It is still worth having the influenza vaccination, because it will always provide some protection. Even if your child did become infected, despite being vaccinated, their illness will be less severe than if they weren't vaccinated.

      Developed by The Royal Children's Hospital. We acknowledge the input of RCH consumers and carers.

      Reviewed May 2023.

      This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

      Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit


    This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.