An immunogenic fusion protein includes at least, on the C-terminal side, a first peptide composed of the S protein deleted of the transmembrane domain thereof located at the N-terminal end thereof, of a hepatitis B virus (HBV) isolate, and on the N-terminal side, a second peptide composed of the transmembrane domain and of the ectodomain of at least one envelope protein of a hepatitis C virus (HCV) isolate. A hybrid nucleic acid molecule encoding the fusion protein, and a vector including the hybrid nucleic acid molecule, a subviral particle including the fusion protein, an immunogenic composition including at least the fusion protein, or at least the hybrid nucleic acid molecule, or at least the subviral particle, and a cell line for the production of the fusion protein, or of the hybrid nucleic acid molecule, or of the subviral particle are described.