Impact of universal immunization program with monoclonal antibody nirsevimab on reducing the burden of serious bronchiolitis that need pediatric intensive care.

• In October 2023, universal immunization with monoclonal antibody nirsevimab of all children under 6 months of age was started in the majority of autonomous communities in Spain. • Recent publications from the nirsevimab clinical trials have evidenced a high RSV protective effect, but data on its effect on real life patients who require pediatric intensive care unit admission are missing.