ABSTRACT
ABSTRACT Bronchiolitis induced by infection with respiratory syncytial virus is a common cause for hospitalization in infants under 6 months of age. Moreover, epidemiological studies show a relationship between early lower respiratory disease as a result of RSV infection and development of asthma-like symptoms during childhood. An effective and safe licensed vaccine for RSV is not available. A formalin-inactivated whole RSV vaccine (FI-RSV) used in a trial performed in the 1960s primed vaccinees for substantial immune pathology following infection with the natural virus. This event has set back the development of novel vaccines. The mechanism behind FI-RSV induced enhanced disease as well as the mechanism of severe disease during primary infections is still poorly understood. The present review summarizes our current understanding of possible elements of the adaptive and innate immune responses that may determine the balance of efficacious immunity versus virus induced or immune mediated pathology.
