Abstract 4366407: Real-World Cardiorespiratory Impact of Respiratory Syncytial Virus (RSV) Vaccination in the USA: A Retrospective Propensity-Matched Analysis

Background: Data from observational studies revealed significant complications after respiratory syncytial virus (RSV) infections. Following results from randomized trials, the Food and Drug Administration approved the RSV vaccine for adults over 60 years in May 2023. Objective: We aim to evaluate the real-world cardiorespiratory impact of RSV vaccination since FDA approval. Methods: We identified adults ≥60 years who received any vaccination between May 2023 and May 2024 using the TriNetX US Collaborative network. Two cohorts were created: those who received the RSV vaccine and those who received other vaccines aside RSV and contracted the RSV infection. Using propensity score matching (PSM) on 32 covariates (demographics, cardiovascular medications, other vaccines and comorbidities), we compared the primary outcome—major adverse cardiovascular and cerebrovascular events (MACCE) defined as a composite of all-cause mortality, acute myocardial infarction, and ischemic stroke—and secondary outcomes including heart failure, bacterial pneumonia, respiratory failure, acute kidney injury, and ICU admission. Odds ratios (OR), 95% confidence intervals (CI), and p-values were estimated at 3, 6, and 12 months. Results: The RSV vaccine cohort had 77,656 patients while the RSV infection cohort had 3,166 patients. After PSM, each cohort had 3,157 patients. The vaccine cohort was associated with lower odds of MACCE (OR 0.22; 0.15-0.34; p<0.0001), all-cause mortality (OR 0.16; 0.09-0.27; p<0.0001), acute MI (OR 0.15; 0.08-0.31; p<0.0001), bacterial pneumonia (OR 0.22; 0.13-0.36; p<0.0001), respiratory failure (OR 0.29; 0.18-0.48; p<0.0001), heart failure (OR 0.32; 0.19-0.55; p<0.0001), AKI (OR 0.44; 0.28-0.69; p=0.0004) and ICU admission (OR 0.20; 0.12-0.35; p<0.0001). These differences remained significant at 6 months and 12 months. Ischemic stroke did not reach significance at any interval. P-values confirmed significant MACCE reduction across all time points (p<0.0001). Conclusion: This retrospective study provides real-world evidence to suggest that RSV vaccination in adults ≥60 years is associated with consistently reduced odds of all-cause mortality, acute MI, respiratory failure, heart failure and ICU admission. RSV vaccination did not have a significant effect on risk of stroke.