Although a prominent cause of upper and lower respiratory tract disease in infants and the elderly, clinical options for treatment of respiratory syncytial virus (RSV) infections remain limited. Historically, attempts to develop vaccines have been unsuccessful, and rapid viral mutation rates have stifled development of several small molecule-based antiviral agents. Thus, targeted approaches to block RSV replication, including humanized monoclonal antibodies and nucleic acid-based strategies (antisense and RNA interference), have emerged as potentially viable drug development options.