Antiviral therapies for respiratory syncytial virus infection: current expectations

Respiratory syncytial virus (RSV) remains a leading cause of bronchiolitis in infants and young children, of pneumonia in children under 5 years of age and is also associated with significant mobility and mortality in immunocompromised patients and older adults. As RSV epidemiology evolves and our preventive strategies expand, developing safe and effective antivirals have the potential to significantly change the trajectory of RSV infections in children.

The landscape of RSV prevention has undergone substantial progress in recent years, and early reductions in burden of acute disease has already been observed among infants who have received these preventive interventions. Nonetheless, RSV continues to pose significant challenges, particularly in regions where prophylactic measures have not yet been implemented, in older children who remain vulnerable beyond their first RSV season and in special patient populations with a weakened immune system. Therapeutic options remain limited: ribavirin is currently the only approved antiviral for severe RSV-LRTI, and despite modest efficacy, its use is largely restricted to immunocompromised patients. Several antivirals with distinct mechanisms of action, have been evaluated in the past decade, but many were discontinued due to limited clinical benefits or concerns with safety. Nonetheless, three major classes of antivirals (fusion inhibitors, polymerase inhibitors and N-protein inhibitors) are now in development with promising results.

This review provides an updated overview of current antivirals against RSV, highlighting the need to develop new therapeutic drugs to reduce both acute disease severity and associated long-term respiratory morbidity.