FLUMIST

What it is

FLUMIST is an influenza virus vaccine (live attenuated) nasal spray. Each 0.2 mL dose contains 10^7.0±0.5 FFU (fluorescent focus units) of each of three live attenuated influenza virus reassortant strains propagated in specific pathogen-free eggs from SPF chicken flocks. The three strains used for the 2026 season are A/Missouri/11/2025 (H1N1) pdm09-like virus, A/Singapore/GP20238/2024 (H3N2)-like virus, and B/Austria/1359417/2021 (B/Victoria lineage)-like virus. FLUMIST contains hydrolysed gelatin (porcine Type A). Residual amounts of ovalbumin (<0.24 μg/dose; an egg protein) and traces of gentamicin sulfate (<0.015 μg/dose; a trace residue) from the manufacturing process may be present.

Approved indications

— Prevention of influenza in children and adolescents from 24 months to less than 18 years of age.

Dosing overview

Children aged 24 months to 8 years require either one or two doses of 0.2 mL (administered as 0.1 mL per nostril), with two doses recommended for those not previously vaccinated against seasonal influenza and one dose for those previously vaccinated. Children aged 9 years to less than 18 years require a single dose of 0.2 mL (administered as 0.1 mL per nostril). If two doses are given, they should be administered at least 4 weeks apart. FLUMIST is for nasal use, administered as a divided dose.

Key safety warnings

FLUMIST should not be administered to children younger than 12 months. In a clinical study, an increase in hospitalisations was observed in children younger than 12 months after vaccination with FLUMIST. It is not recommended to administer FLUMIST to children 12–23 months of age, as an increased rate of wheezing was observed in this age group after vaccination in clinical studies. Individuals with severe asthma or active wheezing have not been adequately studied in clinical studies. If Guillain–Barré syndrome has occurred within 6 weeks of any prior influenza vaccination, the decision to give FLUMIST should be based on careful consideration of the potential benefits and potential risks. FLUMIST is an attenuated live virus vaccine and has the potential for transmission to immunocompromised contacts. Vaccine recipients should attempt, whenever possible, to avoid close association with severely immunocompromised individuals (such as bone marrow transplant recipients requiring isolation) for 1–2 weeks following vaccination.

Contraindications

FLUMIST should not be administered to children and adolescents who have had a severe allergic reaction (such as anaphylaxis) to the active substances, any of the excipients (such as gelatin), gentamicin, eggs or egg proteins (such as ovalbumin). FLUMIST is contraindicated in children and adolescents with clinical immunodeficiency due to conditions or immunosuppressive therapy such as acute and chronic leukaemias, lymphoma, symptomatic HIV infection, cellular immune deficiencies, and high-dose corticosteroids. FLUMIST is contraindicated in children and adolescents less than 18 years of age receiving salicylate therapy because of the association of Reye's syndrome with salicylates and wild-type influenza infection.

Regulatory history

FLUMIST was first listed on the ARTG on 18 November 2025 under licence category RE.