Advances in RSV Immunoprophylaxis: Evolution, Efficacy, and Implementation Challenges.

Respiratory syncytial virus (RSV) poses a critical global health challenge, causing more than 33.1 million acute lower respiratory tract infections and more than 118 000 deaths annually in children younger than 5 years of age. The burden falls disproportionately on infants younger than 12 months of age, with devastating impacts on health care systems worldwide. Prevention strategies have evolved from early vaccine attempts through first-generation monoclonal antibodies to current next-generation antibodies with extended half-lives and novel vaccination approaches in pregnant persons. These recent advances demonstrate unprecedented efficacy, with clinical trials showing reduction rates exceeding 70% in RSV-associated hospitalizations across diverse infant populations. Although economic analyses suggest favorable cost-benefit ratios, implementation raises important considerations regarding health care delivery systems and global access equity. This comprehensive review synthesizes evidence-based guidelines, evaluates implementation challenges, and explores future directions for RSV prevention, with particular attention to regional variations in health care delivery and emerging challenges from changing climate patterns affecting RSV seasonality.