Revised: 12 November 2024

Medicines

Influenza Vaccine Composition

The Australian Influenza Vaccine Committee (AIVC), with a New Zealand representative, met to consult on the influenza vaccine composition for the 2025 southern hemisphere influenza season in October 2024. The information below describes the AIVC recommended influenza vaccine composition for the southern hemisphere in 2025.

For trivalent vaccines for use in the 2025 southern hemisphere influenza season:  

Egg-based vaccines 

• an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
• an A/Croatia/10136RV/2023 (H3N2)-like virus; and
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

Cell culture-, recombinant protein- or nucleic acid-based vaccines

• an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
• an A/District of Columbia/27/2023 (H3N2)-like virus; and
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

The recommendation for the B/Yamagata lineage component of quadrivalent influenza vaccines remains unchanged from the previous recommendation:

• a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

Furthermore, the AIVC supports the World Health Organization (WHO) influenza vaccine committee’s view that continued absence of confirmed detection of naturally occurring B/Yamagata lineage viruses after March 2020 is indicative of a very low risk of infection by B/Yamagata lineage viruses, and continued inclusion of this antigen is no longer warranted. Every effort should be made to exclude this component from vaccines as soon as possible.

Candidate Vaccine Viruses (CVV) recommended for H1N1 and H3N2 are different for egg- and cell-based vaccines as, in some instances, the same virus is not optimal for both production systems. When this is the case, different viruses with similar properties are selected as the prototypes to facilitate timely vaccine production. For more information, see the Questions and Answers document (PDF, 229 KB, 8 pages), published on the World Health Organization’s (WHO) website.

For the candidate vaccine viruses recommended for the 2025 southern hemisphere influenza season, see the WHO's vaccine viruses and reagents web pages.

The recommended influenza vaccine composition is based on the outcome of:

• the meeting of the Australian Influenza Vaccine Committee, with a New Zealand representative, to consult on the influenza vaccine composition for 2025 (held on 9 October 2024)
• information on international surveillance by the WHO Global Influenza Surveillance and Response System
• analysis of recent data on epidemiology and strain characterisation
• the recommendations of the WHO annual consultation on the composition of 2025 influenza vaccines for the southern hemisphere.

Medsafe encourages sponsors wanting to introduce seasonal composition updates for approved influenza vaccines to notify the associated changes in two discrete stages.

Stage 1: A CMN (Form B; change category Labelling - G2) to update labelling and literature. This CMN must include a commitment to not distribute affected product until a relevant CMN (see Stage 2 below) to update the formulation has been consented.

Stage 2: A CMN (Form B; change category Formulation – G1) for approval of the updated formulation. This CMN to update the vaccine formulation (with regards to virus strains) should include the following information:

• Summarised quality control information for Master and Working Seed Lots proposed for use in the forthcoming campaign, including strain history, and results from testing for sterility, mycoplasma, identity of haemagglutinin and neuraminidase, and egg infectivity. If results from genetic analysis are not available, sponsors should provide an estimated date for the provision of this data.
• An assessment of the risks of contamination of the product with extraneous agents, updated as relevant with regards to new or emerging viruses potentially present in materials or clinical isolates used to generate the new seeds.
• Batch analysis data (including verification of HA and NA, and validation of splitting/solubilisation (as relevant) and inactivation) for three monovalent pooled harvest batches made at commercial scale using the proposed seeds. Data should be compared to relevant compendial monograph requirements. Sponsors should also provide particle size analysis for new strains.
• Qualification of SRD testing of HA content in drug substance and drug product using defined standard antigens and antisera. Demonstration of specificity of B-strain reagents should include evidence for a lack of cross-reactivity between the B-strain viruses from the quadrivalent product.
• Stability data from testing of drug substances and drug product in recent years to support the proposed shelf life for the forthcoming campaign, along with a protocol to monitor stability of drug substances and drug product from the forthcoming campaign. Sponsors should also provide any stability data obtained to date from the forthcoming campaign, and a commitment to inform Medsafe of OOS results or aberrant trends that may arise.
• Confirmation that the product is in full compliance with a relevant Ph. Eur. monograph for influenza vaccine (specify which monograph).
• Data from release testing of three batches of SH finished product from the forthcoming season, or a commitment to forward this as soon as available.
• Prior to their distribution, commitment to forward Certificates of Analysis for the first three vaccine lots intended for the New Zealand market in the forthcoming season.

For further guidance about these information requirements, see the European Medicines Agency document, EMA/CHMP/BWP/310834/2012 Guideline on Influenza Vaccines – Quality Module (PDF, 356 KB, 34 pages).