Neonatal World Conference 2026

Abstract

Respiratory syncytial virus (RSV) remains one of the leading causes of lower respiratory tractinfections and hospitalizations in infants worldwide. Preventive strategies have evolved from supportive care toward targeted immunoprophylaxis. This research provides a comparative evaluation between two novel preventive approaches — the monoclonal antibody nirsevimab and the maternal RSV prefusion F (RSVpreF) vaccine — both designed to reduce RSV-related morbidity and mortality in early infancy. The study synthesizes available clinical evidence from pivotal phase III trials and real-world data, analyzing differences in mechanism, timing, and protective efficacy. Nirsevimab, a long-acting monoclonal antibody, has demonstrated over 74% efficacy in preventing medically attended RSV-associated lower respiratory tract infections and up to 90% efficacy in reducing RSV-related hospitalizations during the first RSV season. In contrast, maternal RSVpreF vaccination, administered during late pregnancy, provides passive transplacental immunity, achieving a similar reduction in severe RSV disease but with slightly shorter duration of infant protection. Both modalities exhibit excellent safety profiles, supporting their complementary use within regional immunization frameworks. Integration of maternal vaccination with monoclonal antibody prophylaxis may provide broader and more sustained protection across the first six months of life, particularly in
high-risk neonates or preterm infantspreterm infants. This research has undergone prior peer review and contributes to the growing evidence supporting evidence-based RSV prevention strategies in infancy.