The Australian Influenza Vaccine Committee (AIVC) met on Wednesday 7th October 2020, to recommend the composition of the influenza virus vaccines for 2021. At this meeting, the expert committee reviewed and evaluated data related to epidemiology, antigenic and genetic characteristics of recent influenza isolates circulating in Australia and the Southern Hemisphere, serological responses to the 2019-2020 vaccines, and the availability of candidate vaccines viruses and reagents.
The committee recommended that the following viruses be included in quadrivalent influenza vaccines for the 2021 Southern Hemisphere influenza season:
Egg-based quadrivalent influenza vaccines:
- an A/Victoria/2570/2019 (H1N1)pdm09-like virus;
- an A/Hong Kong/2671/2019 (H3N2)-like virus;
- a B/Washington/02/2019-like (B/Victoria lineage) virus; and
- a B/Phuket/3073/2013-like (B/Yamagata lineage) virus.
Cell-based quadrivalent influenza vaccines:
- an A/Wisconsin/588/2019 (H1N1)pdm09-like virus;
- an A/Hong Kong/45/2019 (H3N2)-like virus;
- a B/Washington/02/2019 (B/Victoria lineage)-like virus; and
- a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.
The composition of trivalent influenza vaccines is recommended to include the H1N1, H3N2 and the B Victoria lineage virus.
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. Further information is available in Frequently Asked Questions- external site on the World Health Organisation's website.
The AIVC recommendation for the composition of influenza vaccines for Australia in 2021 differs from last year's southern hemisphere recommendation with the inclusion of two new strains for the A (H1N1)-like and A (H3N2)-like viruses. The recommended virus for H3N2 has been previously included in the northern hemisphere vaccine.
The recommendation made by AIVC aligns with the recommendation made by the World Health Organisation (WHO recommendations for the 2021 Southern Hemisphere vaccines- external site)
The TGA has accepted the recommendation of the AIVC.
The TGA considers that the following viruses or reassortants are suitable vaccine strains:
- those as listed on the WHO Influenza vaccine web pages: Influenza vaccine viruses and reagents- external site for H1N1, H3N2 and B viruses.
If other candidate vaccine viruses or reagents become available their suitability for use should be discussed with the TGA by emailing influenza.reagents@health.gov.au.