The recommended composition of influenza vaccines for Australia in 2026 introduces two new strains for the Influenza A (H1N1)pdm09 and A (H3N2) subtype viruses when compared to the composition of vaccines for Australia in 2025.

In 2026, there will be Egg-based and Cell-based trivalent influenza vaccines available in Australia.

The Egg-based trivalent influenza vaccine components for the Australian 2026 influenza season will contain the following: 1

• an A/Missouri/11/2025 (H1N1)pdm09-like virus;
• an A/Singapore/GP20238/2024 (H3N2)-like virus;
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

The Cell-based trivalent influenza vaccine components for the Australian 2026 influenza season will contain the following: 1

• an A/Missouri/11/2025 (H1N1)pdm09-like virus;
• an A/Sydney/1359/2024 (H3N2)-like virus;
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

Transition to trivalent vaccines:
The 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. Consistent with the World Health Organization (WHO) recommendations since September 2023, it remains the opinion of the WHO influenza vaccine composition advisory committee that the inclusion of a B/Yamagata lineage antigen is no longer warranted. As a result, there will no longer be updated recommendations for the B/Yamagata lineage component. This position is fully supported by the Australian Influenza Vaccine Committee (AIVC), which recommends the use of trivalent influenza virus vaccines within Australia for the 2026 influenza season.

Vaccination remains your best defence against influenza, as recommended by the World Health Organization. 2