The flu vaccine protects young children from influenza

What the research found

A 2025 review of 109 studies in children and teens found the flu vaccine was about 50% effective against any influenza. This was similar for the nasal spray and the injection. A 2020 review of 28 studies in children aged 6 months to 17 years found 57.48% protection against flu-related hospitalisation.

A 2024 review of 191 studies across all ages found overall effectiveness of 41.4%. It varied by strain, from 55.4% against A/H1N1 to 26.8% against A/H3N2. Protection changes from year to year as the vaccine is matched to circulating strains.

Australian guidance says children under 5 are at higher risk of hospitalisation from flu. It recommends yearly vaccination from 6 months of age and describes the vaccine as safe and effective. One review noted protection can be lower in very young children.

What it doesn’t mean

• The vaccine lowers the risk of flu but does not remove it. A vaccinated child can still catch the flu, and protection varies by season and strain.
• Children under 9 getting the flu vaccine for the first time need 2 doses, at least one month apart. Children aged 6 months to under 2 years should only have the injection, not the nasal spray.
• Common side effects are mild pain, redness or swelling where the needle went in, usually gone within a few days. Talk to your GP or child health nurse if your child has a medical condition or you have questions about timing.