Prevention of RSV bronchiolitis in infants with maternal immunization or monoclonal antibodies for the newborn: What do women choose?

INTRODUCTION: Maternal vaccination against RSV and nirsevimab administered to the newborn are the two strategies equally recommended in France for preventing lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV) in infants. Data about their respective uptake and factors influencing mother's choice are still lacking. METHODS: We conducted a survey through an anonymous self-administered questionnaire that was proposed during post-partum hospitalization to all mothers who gave birth in January 2025 in a French university hospital maternity ward. We collected data to assess the respective administration rates of both methods and analysed reasons underlying women's choice : prior knowledge of RSV prevention, information received during pregnancy, and factors associated with the choice of each preventive strategy. RESULTS: Of the 401 mothers eligible during the survey period, 274 were included. In all, 73.7% (202/274) chose maternal vaccination, 19.3% (53/274) chose nirsevimab and 6.9% (19/274) did not choose any prevention. Mothers who opted for maternal vaccination (n=202) stated that their choice was guided by immediate protection at birth (81.2%), the absence of injection for their newborn (60.4%) and the advice of their gynaecologist or midwife (49.5%). Mothers who opted for nirsevimab (n=53) stated that their choice was guided by the lack of long-term safety data on the vaccine (39.6%) and fear of vaccine adverse effects (35.8%). CONCLUSION: Within one year of its introduction in France, maternal RSV vaccination was the predominant chosen strategy for preventing bronchiolitis in this study population. This is likely due to the preventive advice they received from healthcare professionals, as well as their desire to avoid an injection for their newborn.