An immunogenic complex comprising i) an
amino acid sequence of an N-terminal region of a group B
Streptococcus surface protein selected from the group consisting of: a first
amino acid sequence having at least 98%, such as 99%, identity to SEQ ID NO: 16 and a length of 172 amino acids to 178 amino acids; a second
amino acid sequence having at least 98%, such as 99%, identity to SEQ ID NO: 18 and a length of 167 amino acids to 173 amino acids; and a third amino acid sequence consisting of SEQ ID NO: 20; and ii) a capsular
polysaccharide, is provided. An immunogenic product, a vaccine, and the immunogenic complex, the immunogenic product or the vaccine for use in a method of preventing or treating a group B
Streptococcus infection, are also provided.