- The 2023 influenza season was characterised by an early peak and longer duration, but overalllower clinical severity and societal impact, than many pre-COVID-19 pandemic influenza seasons.This was likely influenced by the high effectiveness of the 2023 seasonal influenza vaccine, and thepredominant circulation of influenza A(H1N1) and influenza B viruses:
- Influenza A(H1N1) is typically associated with less severe illness in older adults compared toinfluenza A(H3N2);
- Influenza B viruses primarily affected younger people in 2023, who are generally at lowerrisk of severe complications and death; and
- Vaccine effectiveness against influenza A(H1N1) and influenza B is usually higher than
- against A(H3N2) and was confirmed to be high in 2023 interim analyses.
- However, vaccination coverage was low overall in 2023, especially in children, and severepresentations to sentinel hospitals in children were reported throughout the season.
- In the reporting period, of the 252,296 notifications of laboratory-confirmed influenza, 376 influenzaassociated deaths were notified to the National Notifiable Disease Surveillance System (NNDSS).
- From the commencement of seasonal surveillance in April 2023, there were 3,696 sentinel hospital admissions, of which 256 (7%) were admitted directly to ICU.
- Seasonal vaccination remains a safe and effective way to protect against severe influenza
Source: https://www.health.gov.au/sites/default/files/2023-12/aisr-2023-national-influenza-season-summary.pdf