Influenza Deaths in Australia: Annual Trends & Statistics

Influenza mortality in Australia varies substantially year to year, driven by circulating strains, vaccine match, population immunity, and surveillance intensity.

Recent Annual Estimates (Influenza-Associated Deaths)

Season	Estimated Deaths	Dominant Strain(s)	Notes
2017	~1,100	A(H3N2)	High severity; vaccine mismatch
2018	~1,800	A(H1N1)pdm09	Moderate severity
2019	~4,000	A(H3N2)	Highest in decade; early peak
2020	~36	Minimal circulation	COVID NPIs suppressed flu
2021	~0	Virtually none	Border closures, NPIs
2022	~300	A(H3N2), A(H1N1)	Rebound season; lower immunity
2023	~1,500 (prelim)	A(H1N1)pdm09, B/Victoria	Moderate; ongoing surveillance

Key Points

• WHO estimate (pre-COVID): 1,500-3,000 annual deaths average.
• Modeling vs. reported: Lab-confirmed deaths represent ~5-10% of estimated total (statistical models account for under-testing, coding).
• High-risk groups: ≥65 years (90% of deaths), Indigenous Australians, chronic medical conditions, pregnant women, children <5.
• Vaccination impact: 40-60% effectiveness; prevents hospitalization/death even with mismatch.

Data Sources

• Australian Influenza Surveillance Report (AISR) – Department of Health.
• National Notifiable Diseases Surveillance System (NNDSS).
• FluCAN (hospital sentinel surveillance).
• ABS cause-of-death data (ICD-10 J09-J11).

Annual vaccination remains the cornerstone of prevention. The 2024 quadrivalent vaccine covers A(H1N1)pdm09, A(H3N2), B/Victoria, B/Yamagata.