Respiratory Syncytial Virus (RSV) is a globally prevalent cause of lower respiratory tract infection in all age groups. In infants and young children, the first infection may cause severe bronchiolitis that can sometimes be fatal.
In addition to the paediatric burden of disease, RSV is increasingly being recognised as an important pathogen in older adults, with infection leading to an increase in hospitalisation rates among those aged 65 years and over, and to increased mortality rates among the frail elderly that approach the rates seen with influenza.
RSV is also a nosocomial threat both to young infants and among immunocompromised and vulnerable individuals.