The invention relates to modified Bordetella adenylate cyclase toxins which are deficient for CD11b/CD18 binding and to their use in the preparation of pharmaceutical composition for the treatment of whooping cough and/or for the protection against Bordetella infection. The invention also relates to specific fragments of Bordetella adenylate cyclase comprising the CD11b/CD18 interaction domain and their use, especially for targeting a molecule of interest to CD11b expressing cells.