Simultaneous vaccination against influenza and respiratory syncytial virus in high-risk heart failure patients.

Background: There is a scarcity of prospective data on the impact of available vaccinations against respiratory viruses on hard clinical endpoints in patients with heart failure (HF).

Aims: We investigated whether, in the population of high-risk HF patients, simultaneous vaccination against influenza and respiratory syncytial virus (RSV) improves outcomes during the subsequent infection season.

Methods: We conducted a prospective, randomized, single-centre, open-label study in which patients with high-risk HF were randomized 1:1 to simultaneous influenza and RSV vaccination or standard of care (SOC). The primary composite endpoint comprised all-cause death, HF hospitalization (HFH) or clinical signs/symptoms of infection within a 6 month follow-up period (regular structured telephone interview). Secondary endpoints were components of the composite primary endpoint.

Results: Two hundred twenty patients were randomized. During the follow-up period, the primary endpoint occurred in 59% of patients in the vaccination group versus 75% in the SOC group [hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.48-0.92, P = 0.01]. Regarding the secondary endpoint analyses, during 6 month follow-up, 3% in the vaccination group died compared with 5% of patients in the SOC arm (HR 0.50, 95% CI 0.12 1.99, P = 0.32), and 18% versus 16% of study participants were hospitalized for HF in the two study arms, respectively (HR 0.86, 95% CI 0.45-1.62, P = 0.64). Infection occurred in 53% of vaccinated patients compared with 68% in SOC (HR 0.68, 95% CI 0.48-0.96, P = 0.03).

Conclusions: In the population of high-risk HF, simultaneous vaccination against influenza and RSV reduced the incidence of the primary outcome. The effect was driven by a significant reduction in infections.