Drug candidates and model systems in respiratory syncytial virus antiviral drug discovery

The development of antiviral strategies to prevent or treat respiratory syncytial virus (RSV) infections is of great importance, especially considering the fact that RSV is one of the most important causes of pediatric respiratory infections. However, despite intense efforts, there is no antiviral or vaccine approved for the prevention or treatment of RSV infections. Several inhibitors, targeting different RSV proteins have been discovered over the past decade. We here review the most important chemical series as well as recent developments in understanding which viral proteins and/or host cell factors are good targets for inhibition of viral replication. In addition, we highlight the current in vitro and in vivo model systems of the disease. A number of molecules are currently in (advanced) preclinical or clinical development. Significant breakthroughs in the field may be expected in the upcoming years.