The invention concerns a fusion polypeptide comprising a plurality of conserved peptide sequences, or variants thereof, wherein at least one of the conserved sequences is conserved across: i) HCV genotypes 1a and 1b； ii) HCV genotypes 1 and 3； or iii) HCV genotypes 1 to 6； and wherein at least one of the conserved peptide sequences comprises at least part of a sequence of a non-structural protein of the HCV genotypes； including associated nucleic acid and vector sequences, and use in methods of treatment or prophylaxis, such as vaccination.
