Assessing the Efficacy and Implementation of Nirsevimab for RSV Prevention in Infants: Global Insights and Recommendations for Hong Kong

Abstract

Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection (LRTI) and hospitalization in infants globally, including in Hong Kong (HK), yet preventive options remain limited. Although palivizumab has historically been used for high-risk infants, its high cost and monthly dosing have restricted broader applicability. Nirsevimab, a long-acting monoclonal antibody that provides season-long protection after a single dose, has shown substantial efficacy against RSV-associated LRTI and hospitalization in clinical trials and real-world studies, and is now being rolled out in various high-income countries. However, implementation in HK poses unique challenges related to the city’s prolonged and variable RSV seasonality, public health infrastructure, and cost-effectiveness thresholds. This narrative review examines the clinical evidence, global implementation experience, and the ethical, epidemiological, and economic considerations relevant to the potential introduction of nirsevimab in HK. It argues that a localized implementation model—featuring timing based on birth month and seasonal risk, delivery integrated through Maternal and Child Health Centers and District Health Centers, and phased introduction supported by district-based pilot testing and comprehensive post-marketing surveillance—may offer a pragmatic, sustainable, and equity-oriented pathway for introducing nirsevimab into HK’s infant preventive healthcare strategy.