Safety and efficacy of maternal RSV vaccination: a systematic review and meta-analysis

Respiratory syncytial virus (RSV) maternal vaccination has emerged as a preventive strategy to confer passive immunity to newborn during their early vulnerable months of life. In this review, we aim to assess the efficacy and safety of maternal RSV vaccines. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines for systematic reviews and meta-analyses. Our literature search covered MEDLINE via PubMed, Scopus, Web of Science, and Cochrane. We included randomized controlled trial (RCTs) that assessed the safety and efficacy of maternal RSV vaccines. The overall effect estimates for efficacy outcomes, including RSV-associated lower respiratory tract infection (LRTI), severe LRTI, and hospitalizations, demonstrated statistically significant benefits favoring the maternal RSV vaccine group (risk ratio [RR], 0.44, 95% confidence interval [CI], 0.31, 0.62, p=0.0001; RR, 0.30, 95% CI, 0.19, 0.48, p=0.0001; RR, 0.53, 95% CI, 0.37, 0.75, p=0.0004, respectively). Additionally, no statistically significant differences were identified for fetal or neonatal safety outcomes, including congenital abnormalities, intrauterine growth restriction, stillbirth, or infant death. Regarding preterm birth, the overall effect estimate did not show a significant difference between the vaccine and control groups (RR, 1.16, 95% CI, 0.96, 1.41, p=0.12). Maternal RSV vaccination provides protection against RSV-associated lower respiratory tract illness in infants with no major safety concerns. However, current evidence remains limited, and additional data from high-quality RCTs are required to confirm or refute these findings. Copyright © Korean Vaccine Society.