Abstract: A compound of general formula (I): wherein R1 and R2 may be the same or different and are selected from the group consisting of hydrogen, optionally substituted C4-30 alkyl and optionally substituted C4-30 alkenyl, provided that R1 and R2 may not both be hydrogen, or R1 and R2 together with the nitrogen atom from which they depend form a saturated or unsaturated, optionally substituted heterocyclic group which may include additional heteroatoms selected from the group consisting of O, N and S, or R1 and R2 together with the nitrogen atom from which they depend form an optionally substituted lactam moiety; X1 is selected from the group consisting of OR3, SR3, NR3R?3, hydrogen, halogen, CN, C(O)NR3R?3, C(O)OR3, OSO3R3, OPO3R3, NNR3R?3, SNR3R?3, NHSR3, SSR3 and substituted alkyl; X2 is selected from the group consisting of OR4, SR4, NR4R?4, hydrogen, halogen, CN, C(O)NR4R?4, C(O)OR4, OSO3R4, OPO3R4, NNR4R?4, SNR4R?4, NHSR4, SSR4 and substituted alkyl; X3 is selected from the group consisting of OR5, SR

Abstract: DNA molecules comprising polynucleotide sequences substantially corresponding to all or a portion of the base sequence coding for an antigen of Plasmodium falciparum selected from the group consisting of the RESA antigen, the FIRA antigen, and other antigens of P. falciparum cross-reactive therewith. Such DNA molecules are capable of being expressed as polypeptide(s). Synthetic peptides or polypeptides displaying the antigenicity of all or a portion of the RESA or FIRA antigens of P. falciparum. Compositions for stimulating immune responses against P. falciparum antigens in a mammal, comprising at least one polypeptide displaying the antigenicity of the RESA or FIRA antigens of P. falciparum.