The present invention relates to a combination vaccine for the protection of poultry against Ornithobacterium rhinotracheale, to the use of a live over-attenuated Ornithobacterium rhinotracheale strain and a live attenuated poultry virus for the manufacturing of such a combination vaccine and to methods for the preparation of said combination vaccine and to vaccination kits for the immunization of poultry against Ornithobacterium rhinotracheale.