[Expert consensus on monoclonal antibody immunoprophylaxis against respiratory syncytial virus in infants and young children in tropical and subtropical regions of China].

Respiratory syncytial virus (RSV) is one of the main pathogens of acute lower respiratory tract infection in infants and young children and shows a year-round transmission pattern in tropical and subtropical regions, posing a serious health threat, especially to infants under one year of age. Current treatment is mainly symptomatic and supportive, and antiviral drugs have limited efficacy. In recent years, with advances in monoclonal antibody development, the long-acting RSV monoclonal antibody nirsevimab has been introduced into clinical practice worldwide, including in China, and has become a core intervention for immunoprophylaxis in infants and young children. Recommendations are proposed in this consensus based on the latest domestic and international evidence and the epidemiological characteristics of tropical and subtropical regions in China. They cover: epidemiological features of RSV; disease burden and clinical manifestations of RSV infection; dosage and administration of RSV monoclonal antibodies; efficacy and safety of RSV monoclonal antibodies; year-round immunoprophylaxis strategies for infants and young children; immunoprophylaxis strategies for infants and young children with special health conditions; coadministration of RSV monoclonal antibodies with vaccines in the national immunization program; and management measures for immunoprophylaxis with long-acting RSV monoclonal antibodies. The aim is to provide scientific and standardized guidance for frontline clinical and public health practice to reduce the incidence, severity, and public health burden of RSV infection in infants and young children.