An immunogenic fusion protein includes at least the following two peptides a) —;on the C-terminal side, a first peptide constituted of: —;the amino acid sequence of the protein S or the protein M of a human hepatitis B virus (HBV) isolate, which protein S or protein M is optionally deleted at the N-terminal end thereof, and b) —;on the N-terminal side, a second peptide constituted of: —;the sequence of amino acids of at least one transmembrane domain and the ectodomain of at least one protein of a Zika virus isolate selected from the envelope protein E or a fusion peptide including the envelope protein E and the protein prM.