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.