Single-Dose RSV Preventive Maintains Protection Into Second Year for Vulnerable Infants

Clesrovimab, administered as a single injection, demonstrated continued effectiveness and safety when given to high-risk infants during their second respiratory syncytial virus season. The higher 210 mg dose used in year two produced serum concentrations comparable to the first-year dose while maintaining similar rates of RSV disease and hospitalization despite elevated post-pandemic virus activity. Results suggest clesrovimab offers a more convenient alternative to multiple monthly injections for infants requiring extended respiratory protection.

Clesrovimab represents a monoclonal antibody approach to RSV prevention that simplifies treatment logistics for vulnerable infant populations. The drug demonstrated protective efficacy comparable to traditional palivizumab regimens, which require monthly administration throughout the respiratory virus season—a significant practical advantage for families managing high-risk children with chronic conditions or prematurity complications.

The second-year safety and efficacy data are particularly notable given the heightened RSV circulation observed in post-pandemic seasons. By maintaining consistent disease prevention rates while adjusting the dose upward, researchers established a dosing strategy that accommodates growing infants while preserving the drug's protective mechanisms over an extended treatment timeline.