Abstract: An immunization strategy to provide protection against disease caused by infection with a paramyxoviridae virus, specifically respiratory syncytial virus (RSV) and parainfluenza virus, is described. A priming intranasal administration of a recombinant virus expressing at least one RSV or PIV protein or immunogenic sequence there first is made to the host followed by a booster administration of at least one purified RSV or PIV protein or immunogenic fragment thereof, which may be adjuvanted with alum. This immunization strategy provides a safe and effective means of controlling RSV and PIV infections. The strategy leads to a stronger protective immune response than other strategies and to the induction of a more balanced Th-1/Th-2 type response than previously attained.