ABSTRACT
Human respiratory syncytial virus (HRSV) is the leading viral agent of serious pediatric respiratory tract disease, with two-thirds of infants becoming infected during the rst year of life and 90% having suffered one or more episodes of RSV infections by 2 years of age. RSV also causes upper respiratory tract disease in individuals of other age groups, with particular severe consequences in the elderly and immunocompromised individuals. The worldwide annual morbility and mortality due to RSV are estimated to be tens of millions and hundreds of thousands, respectively, with the cost of hospitalization for bronchiolitisin children less than 1 year old amounting to over $700 million per year.
