NEW MATERIAL: Polypeptide having the immunogen determinant from the first flanking region of Plasmodium surface protein and that from the second flanking region thereof and containing the immunogen determinant less than all of repeating immunogen determinants from a repeating domain during this period or containing the same at all.

EXAMPLE: Polypeptide represented by formula.

USE: Maralia vaccine.

PROCESS: A DNA fragment encoding the flanking region of Plasmodium surface protein synthesized by a known method is introduced into the DNA fragment encoding the N-terminal amino acid sequence of carrier protein and a developing vector having a synthetic DNA linker. Subsequently, E.coli is transformed by the vector to synthesize the designated polypeptide.