Maternal RSV vaccination to protect infants: current evidence and future directions

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection (LRTI) burden among infants. Maternal vaccination is a promising preventive strategy, conferring passive immunity through transplacental antibody transfer. The current narrative review was conducted to summarize the current evidence of efficacy and safety of maternal RSV vaccination and assess the practical barriers to its implementation. This review was based on a structured literature search of PubMed/MEDLINE and Google Scholar to identify peer-reviewed studies published between January 2022 and March 2025 using terms such as “maternal RSV vaccine”, “efficacy”, “safety”, “pregnancy”, “Abrysvo”, and “hesitancy”. The review included 5 clinical trials evaluating maternal RSV vaccines and 17 observational and survey studies assessing vaccine acceptance across diverse settings. The bivalent RSVpreF vaccine (Abrysvo) is the only licensed maternal RSV vaccine as of May 2025. In the MATISSE phase 3 trial (n = 7,358), the vaccine demonstrated 81.8% efficacy against medically attended RSV-LRTI at 90 days and 69.4% at 180 days, with 57.1% efficacy against severe RSV-LRTI. No major safety concerns were identified; adverse events and preterm birth rates were comparable between groups. In contrast, trials of GSK’s RSVPreF3-Mat vaccine revealed higher rates of preterm birth (6.8% vs. 4.9%) and a numerical imbalance in infant deaths (0.4% vs. 0.2%), prompting early termination. Across 17 studies (n = 14,959), RSV vaccine acceptance ranged from 39% (France) to 87% (Netherlands), with safety concerns and cultural context influencing attitudes. This review highlights that maternal RSV vaccination with RSVpreF offers effective infant protection with an acceptable safety profile. Future research should focus on long-term infant outcomes, comparative effectiveness in diverse settings, and next-generation vaccines. Implementation will require public trust, cultural sensitivity, and equitable global access.