The development of antiviral therapy and vaccines against respiratory syncytial virus and human parainfluenza virus type 3

Abstract

Respiratory syncytial virus (RSV) and human parainfluenza virus type 3 (HPIV-3) are the major causes of lower respiratory tract infection in infants and young children. RSV is also responsible for a significant amount of morbidity and mortality in the elderly, the immunosuppressed and those with chronic cardiac or pulmonary disease. Despite extensive research, no effective antiviral therapy or vaccine is currently available for either virus. Over the past 20 years a number of different approaches for developing vaccines for RSV and HPIV-3 have been tested, with varying degrees of success. However, as it is not yet possible to identify one strategy that yields a vaccine preparation suitable for all high-risk populations, a multi-faceted approach to RSV and HPIV-3 vaccine development is still necessary. Ribavirin and immunoglobulin preparations with high titres of RSV-specific neutralizing antibodies are licensed for the treatment and prevention of RSV infection, but neither is cost-effective or easy to administer. New clinically effective agents are needed to diminish the impact of RSV and HPIV-3. This article will review the currently available means for controlling the two viruses, the search for new antiviral agents, and future prospects for preventing and treating RSV and HPIV-3 infections.