Respiratory syncytial virus prophylaxis--the story so far.

Respiratory syncytial virus (RSV) is a common and highly contagious pathogen that infects nearly all children by the age of 2 years. It is responsible for significant morbidity and mortality worldwide among certain high-risk paediatric populations. Therapy is sub-optimal for RSV, thus treatment focuses on ameliorating symptoms. Since discovery of the virus in the 1950s, efforts have been ongoing to develop a safe and effective vaccine. These efforts have met with serious obstacles. Passive immunoprophylaxis presents a viable alternative to active immunization. In 1998, the genetically engineered humanized monoclonal antibody (palivizumab) was granted FDA (Food and Drug Administration) approval for prophylaxis of high-risk children in the United States; EMEA (European Agency for the Evaluation of Medicinal Products) approval followed in 1999 for Europe. It is now approved in over 45 countries worldwide. Palivizumab was shown to significantly reduce RSV-related hospitalizations in North America and Europe with few adverse effects. Clinical trial and outcomes data documenting experience with palivizumab to date continue to extend the initial safety and efficacy observations.