The invention relates to a chimeric protein comprising or consisting of, from N-terminal to C-terminal, (a) a N-terminal part of a Bordetella CyaA protein (b) a heterologous polypeptide, and (c) a C-terminal part of a Bordetella CyaA protein. The invention also relates to a polynucleotide encoding a deleted version of a Bordetella CyaA, as well as a polynucleotide encoding this chimeric protein. A composition comprising at least one chimeric protein(s) of the invention and the prophylactic and/or therapeutic uses of said composition are also part of the invention.