“…Respiratory syncytial virus (RSV) is one of the most important respiratory pathogens, causing severe infections of the lower respiratory tract in infants, small children, the elderly, and in immunosuppressed patients, often requiring hospitalization [Kim et al, 1973;Whimbey et al, 1995;Agius et al, 1990;Falsey et al, 1992;Fleming et al, 1993]. Previous infection does not confer immunity and reinfections are very common [McIntosh et al, 1993;Henderson et al, 1979].The virus is highly contagious, causing yearly outbreaks of respiratory tract infections and spreads very rapidly, especially in hospital wards and nursing homes [Falsey et al, 1990.…”