In patients with heart failure (HF), influenza vaccination should be considered to prevent HF hospitalizations. However, vaccination rates among patients with HF are low, in part because of subjective but common concerns about whether patients with such severe disease should be vaccinated. In this randomized, open-label study, we will investigate whether influenza vaccination before discharge in patients stabilized after cardiac decompensation is safe and improves outcomes over a 6-month follow-up period.

Inclusion Criteria:

• informed consent to participate in the study
• hospitalization (unplanned) due to exacerbation (decompensation) of heart failure
• planned discharge within the next 48 hours due to completion of hospital treatment
• no current (2024/25 season) influenza vaccination.

Exclusion Criteria:

• severe post-vaccination reaction during influenza vaccination in any previous influenza season
• hypersensitivity to any of the components of the vaccine planned to be administered
• discharge to another hospital for continued treatment or discharge to a nursing home
• antibiotic therapy among the drugs recommended for taking after hospitalization.