Effectiveness of respiratory syncytial virus vaccination in solid organ transplant recipients in the United States

Respiratory syncytial virus (RSV) is associated with high morbidity in solid organ transplant recipients (SOTRs) and the effectiveness of the RSV vaccine in this population is unknown. We sought to assess the real-world performance of the RSV vaccine in SOTRs through a retrospective cohort study emulating a target trial using Epic Cosmos. We identified SOTRs with posttransplant follow-up between October 1, 2023, and March 31, 2025, and were aged ≥60 years. Risk-set matching was used to account for the timing of vaccination. Outcomes included RSV infection, hospitalization, intensive care unit admission, intubation, and all-cause mortality. Multivariable Cox regression was used to compare RSV-related events between vaccinated and unvaccinated SOTRs. Of 63 108 total patients, 17 315 vaccinated SOTRs were risk-set matched to 34 617 unvaccinated SOTRs. After adjusting for relevant confounders, vaccination was associated with a lower risk of RSV infection (hazard ratio [HR], 0.70; 95% CI, 0.56-0.88; P = .002), RSV-related hospitalization (HR, 0.61; 95% CI, 0.43-0.86; P = .005), and all-cause mortality (HR, 0.45; 95% CI, 0.41-0.50; P < .001), but not intensive care unit admission or intubation. These findings were largely consistent across sensitivity and subgroup analyses. RSV vaccination is associated with lower risk for RSV infection, RSV-related hospitalization, and all-cause mortality among SOTRs. SOTRs should be encouraged to receive the RSV vaccine.