Respiratory syncytial virus infection in adults: Clinical manifestations, outcomes, and vaccines

Respiratory syncytial virus (RSV) is an RNA virus transmitted via droplets and affects individuals across all age groups. Although RSV is increasingly being recognized as a key pathogen in adults, differentiating RSV infection from other acute viral infections solely on the basis of clinical features is challenging. Polymerase chain reaction is the gold standard for RSV detection. Notably, RSV accounts for 2% to 10% of all hospitalizations due to respiratory tract infections in adults. Among hospitalized adults with RSV infection, 18.9% require intensive care, experiencing a disease burden similar to that of influenza. Severe RSV infection disproportionately affects older adults with multiple comorbidities, such as chronic heart failure and chronic obstructive pulmonary disease. This review focused on the manifestations and outcomes of RSV infection and on advances in the development of RSV vaccines. We comprehensively searched PubMed for relevant studies published between 1991 and 2024. Evidence-based specific to RSV treatments remain limited, with supportive care being the mainstay of management. In 2023, 2 protein subunit vaccines were approved for individuals aged ≥60 years; in addition, an mRNA-based vaccine that exerts substantial protective effects against severe RSV disease received approval in the United States. The development of novel antiviral therapies and vaccines holds promise for mitigating the burden of RSV infection. However, further research is required to evaluate the real-world effectiveness of vaccines, particularly in high-risk hospitalized patients requiring intensive care or mechanical ventilation, to optimize implementation strategies.