Maternal respiratory syncytial virus vaccination for infant protection: updated systematic review and meta-analysis of efficacy, effectiveness, and safety.

Abstract

Respiratory syncytial virus (RSV) is a major cause of severe illness in infants and young children. We updated this systematic review to explore the efficacy, effectiveness and safety of authorised maternal RSV prefusion F (RSVpreF) vaccine for infant protection. We searched MEDLINE, Cochrane Library/Central, Embase and grey literature from 2000 to June 2025. We included randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs). Meta-analyses of RCTs showed high certainty of evidence that maternal RSVpreF vaccine lowered medically attended RSV-related lower respiratory tract infections (RSV-LRTI) with vaccine efficacy of 68% (relative risk (RR) 0.32; 95% confidence interval (CI) 0.13 to 0.77, 2 trials; 7656 participants), severe RSV-LRTI with a vaccine efficacy of 84% (RR 0.16; 95% CI 0.07 to 0.36, 2 trials; 7656 participants) and RSV-related hospitalisations with a vaccine efficacy of 70% (RR 0.30; 95% CI 0.15 to 0.61, 1 trial; 7148 participants) in infants. Within the limited evidence base available, there may be little to no difference in RSV-related mortality, all-cause mortality, vaccine-related serious adverse events, and intensive care admission. Requirements for invasive ventilation and duration of hospitalisation due to RSV disease were not reported by any trials. NRSIs suggested effectiveness of 72% (RR 0.28; 95% CI: 0.17 to 0.46, 3 NRSIs; 1229 participants) against hospitalisation, but certainty was very low. Maternal RSVpreF vaccination reduced medically attended and severe RSV-LRTI and RSV-related hospitalisation in infants. No safety signals were identified. Further research is required to clarify the long-term effectiveness of the authorised vaccine.