Chemotherapy of respiratory syncytial virus infections: the final breakthrough.

Respiratory syncytial virus (RSV) infection is the leading cause of hospitalisation for children under 5 years of age and causes excess mortality in the elderly. There is still no approved vaccine available, although the disease can be curtailed by RSV-specific monoclonal antibody. The only antiviral drug approved for the treatment of RSV infection is ribavirin aerosol, but this treatment is cumbersome and its efficacy is questionable. A new antiviral, GS-5806, which interferes with virus-cell fusion, has proven efficacious in experimental RSV infections in adults.