<prompt> The most common cause of bronchiolitis is:Respiratory syncytial virusAdenovirusHerpes virusInfluenza virus  <response>: MC organism causing Bronchiolitis is RSV Other organisms are :- Influenza virus Parainfluenza virus Human metapneumovirus Coronavirus Adenovius Rhinovirus Palivizumab injection is used to prevent serious lung infection in children and babies caused by respiratory syncytial virus RSV. 