Southern Hemisphere influenza season

On the 24th of September 2021, the World Health Organisation recommended that the following viruses be included in the Quadrivalent influenza vaccines for the 2022 Southern Hemisphere influenza season. This was ratified by The Australian Influenza Vaccine Committee (AIVC) on Wednesday 6th October 2021.

It is recommended that quadrivalent vaccines for use in the 2022 southern hemisphere influenza season contain the following:

Egg-based vaccines

• an A/Victoria/2570/2019 (H1N1)pdm09-like virus; 
• an A/Darwin/9/2021 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

Cell- or recombinant-based vaccines

• an A/Wisconsin/588/2019 (H1N1)pdm09-like virus; 
• an A/Darwin/6/2021 (H3N2)-like virus;
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.

What is the purpose of the WHO recommendations for the composition of influenza virus vaccines?

These WHO recommendations provide a guide to national public health and regulatory authorities and vaccine manufacturers for the development and production of seasonal influenza vaccines for the next influenza season. In contrast to many other vaccines, the viruses in influenza vaccines are evaluated and updated regularly because circulating influenza viruses evolve continuously.

Why are different viruses sometimes recommended for egg- and cell-based vaccines?

Influenza viruses do not always replicate equally well in the egg- and cell-based vaccine
production systems. Different viruses, which have similar antigenic properties, are
recommended for the two production systems. The use of the cell-based vaccine virus sequences is recommended for recombinant protein or other relevant new platforms of influenza vaccine production.

2022 Influenza Vaccine Strains

Each year the World Health Organization (WHO) puts forward its recommendations for the composition of influenza virus for use in the Southern Hemisphere's influenza season. On the 6th of October, the Australian Influenza Vaccine Committee (AIVC) confirmed their recommendation in line with the WHO recommendations.