Work

Real-world impact of nirsevimab immunisation and maternal RSV vaccination against respiratory disease on emergency department attendances and admissions: a multinational retrospective analysis

Year: 2026

Type: article

Abstract: Background: Nirsevimab, a long-acting monoclonal antibody against respiratory syncytial virus (RSV), was recently introduced in Catalonia (Spain, 2023-2024 season onwards) and Italy (2024-2025 season). The United Kingdom (UK) instead introduced maternal RSV vaccination (RSVpreF) in the 2024-2025 season. Our aim was to analyse emergency department (ED) attendances and admissions to hospital following RSVpreF and nirsevimab introduction, with hospitals in Iceland and Romania, where no intervention was introduced, used as comparators. Methods: Multi-national retrospective analysis of ED attendances and admissions for all diagnoses, respiratory diagnoses excluding bronchiolitis, and bronchiolitis from all hospitals in Catalonia (Spain), four UK hospitals (Bristol, Edinburgh, Glasgow, and Leicester), and one hospital in Italy (Rome), Romania (Bucharest), and Iceland (Reykjavík) from April 2018 to March 2025. Bronchiolitis diagnoses in the 2024-2025 season were compared to previous pre-intervention seasons (2018-2023, excluding the 2020-2021 COVID-19 year) by applying a generalised linear model in Poisson regression to obtain risk ratios (RR) and 95% confidence intervals (95% CI). Findings: In the 2024-2025 season, in Catalonia, there was a reduction in the RR for bronchiolitis ED attendances and admissions in infants of age <6 months (RR 0.45; 95% CI 0.43-0.47 and RR 0.40; 95% CI 0.37-0.43, respectively). This was not seen in Rome, where the RR for ED attendances with bronchiolitis in infants of age <6 months was 1.09 (95% CI 0.92-1.30) and the RR for admissions was 1.12 (95% CI 0.83-1.52). In the UK, for infants of age <6 months with bronchiolitis, there was a significant but modest reduction in 1 out of 4 hospitals for ED attendances (Leicester; RR 0.91, 95% CI 0.85-0.97) and in 2 out of 4 hospitals for admissions (Leicester; RR 0.80, 95% CI 0.69-0.94 and Edinburgh; RR 0.85, 95% CI 0.76-0.95). Interpretation: In Catalonia, there was a sustained reduction in bronchiolitis ED attendances and admissions for infants in the 2024-2025 season. However, no substantial reduction in bronchiolitis ED attendances or admissions was observed in Rome or the UK. These differences are likely to relate to the reduced uptake of RSV prevention products in these settings compared to Catalonia. Funding: None.

Source: The Lancet Regional Health - Europe

DOI: 10.1016/j.lanepe.2026.101597