The U.S. Food and Drug Administration (FDA) has approved Enflonsia™ (clesrovimab-cfor) on June 9, 2025, marking a major milestone in the prevention of respiratory syncytial virus (RSV) infections in newborns and infants. Developed as a passive immunization, Enflonsia is a long-acting monoclonal antibody designed to provide immediate protection against RSV, a leading cause of respiratory illness in young children.
Unlike vaccines, passive immunizations deliver ready-made antibodies to the body offering fast-acting defense. Enflonsia is administered as a single intramuscular injection and is indicated for use in neonates and infants including those born during RSV season or who are entering their first RSV season.
RSV is a common respiratory virus that can cause bronchiolitis and pneumonia in infants, sometimes leading to hospitalization especially in babies under 6 months of age.
Until recently, options for protecting all infants from RSV were limited. The approval of Enflonsia expands preventive options beyond high-risk groups offering broader protection across the infant population.
Clesrovimab-cfor works by binding to a conserved site on the RSV fusion (F) protein, neutralizing the virus and preventing it from entering human cells.
The product has demonstrated favorable safety and efficacy in clinical trials with sustained protection through the peak of RSV season. This approval follows a growing global focus on RSV prevention, as new monoclonal antibodies and maternal immunizations emerge to fill critical gaps in pediatric infectious disease care.
Disclaimer: This article is for informational purposes only and summarizes current medical regulatory updates as of June 2025. It is not intended as a substitute for professional medical advice. Caregivers should consult with healthcare providers for personalized recommendations regarding RSV prevention.
