Uptake and predictors of newborn respiratory syncytial virus (RSV) immunisation with nirsevimab in Ireland’s national pilot programme: a cross-sectional study

OBJECTIVES: To assess uptake of nirsevimab, a long-acting monoclonal antibody for respiratory syncytial virus (RSV) prevention, during the first season of Ireland's Pathfinder pilot universal newborn immunisation programme and to identify socio-demographic and perinatal predictors of uptake. DESIGN: Cross-sectional analysis of routinely collected programme data. SETTING: Ireland's Mid-West region, served by University Maternity Hospital Limerick, the sole maternity and neonatal hospital for the region. PARTICIPANTS: Infants born 1 September 2024 to 28 February 2025. OUTCOME MEASURE: Uptake of nirsevimab before hospital discharge. RESULTS: Overall uptake was 89.4% (1600/1790) and did not vary by month (p=0.119); it was similar by sex (male 89.5%, female 89.2%; p=0.838). Preterm infants had higher uptake than term (96.9% vs 88.7%; p=0.001), and those admitted to the neonatal unit also had higher uptake (93.0% vs 88.4%; p=0.009). In adjusted analyses, maternal age (adjusted OR (aOR) 1.06 per year, 95% CI 1.03 to 1.09, p