Early impact of maternal RSV vaccination on bronchiolitis hospitalisation and critical care admissions in infants under age 3 months, England, September 2024 to March 2026.

We conducted a time series analysis of hospitalisation and critical care admissions to evaluate the impact of maternal respiratory syncytial virus (RSV) vaccination in England from September 2024 to March 2026 in infants < 3 months of age. All bronchiolitis admissions decreased by 39.3% (IRR: 0.607, 95% CI: 0.576-0.640), and RSV bronchiolitis admissions by 62.6% (IRR: 0.374, 95% CI: 0.344-0.407). We estimated a 41.0% reduction in bronchiolitis critical care admissions (IRR: 0.590, 95% CI: 0.531-0.657). Maternal vaccine coverage was 55.1%. These findings support efforts to expand vaccine uptake.