Real-world uptake of nirsevimab, RSV maternal vaccine, and RSV vaccines for older adults: a systematic review and meta-analysis.

Background: In clinical trials, recently introduced respiratory syncytial virus (RSV) immunisation products have shown high efficacy in preventing severe RSV outcomes. Implementing successful immunisation programmes is however key to realising these benefits in real-world settings. We aimed to investigate uptake of the long-acting monoclonal antibody nirsevimab, the RSV maternal vaccine, and RSV vaccines for older adults in countries where immunisation programmes have been introduced, and to explore how uptake varies between countries and population subgroups. Methods: In this systematic review and meta-analysis, we carried out four monthly searches in Medline, Embase, and Global Health databases for studies reporting uptake of nirsevimab, the RSV maternal vaccine, and RSV vaccines for older adults. We included population-based studies published between December 1, 2022 and February 5, 2025. Two independent reviewers screened studies, extracted data, and completed a risk of bias assessment using the Joanna Briggs Institute (JBI) Critical Appraisal Tools. We assessed uptake stratified by country and socio-demographic and clinical subgroups. Meta-analyses were conducted using random-effects modelling. PROSPERO registration number: CRD42025643585. Findings: We screened a total of 1267 studies, 43 of which met the inclusion criteria reporting data on over 1.38 million individuals from six countries. Nirsevimab uptake data were reported in 34 studies: 16 from Spain, eight from the United States, seven from France, one with combined data from Andorra and Spain, and one from each of Italy and Luxembourg. Our pooled estimates showed that nirsevimab uptake on population level was 90.1% (95% confidence interval (CI): 86.4-92.9) in Spain and 51.2% (95% CI: 29.3-72.7) in the United States during the 2023/24 RSV season. Uptake data for the RSV maternal vaccine and RSV vaccines for older adults were reported in five and eight studies, respectively, all from the United States. Meta-analysis showed population-level uptake of 30.5% (95% CI: 20.6-42.6) and 18.2% (95% CI: 10.8-28.9), respectively. Uptake varied across subgroups. Interpretation: Uptake of nirsevimab varied substantially between the countries that have implemented infant RSV immunisation programmes. Despite the limited number of studies and the lack of more accurate data at national level the low uptake estimates for RSV maternal vaccine and RSV vaccines for older adults are concerning. National, clinical, and public health initiatives are needed to increase uptake of RSV immunisation products and ensure maximum benefit to people currently at risk of severe RSV outcomes. Funding: Health Data Research UK, Inflammation and Immunity Driver Programme.