Binding domains from Plasmodium vivax and Plasmodium falciparum erythrocyte binding proteins

A pharmaceutical composition comprising a pharmaceutically acceptable carrier and an isolated cysteine-rich binding domain polypeptide derived from the P. falciparum 175 kDa sialic acid binding protein of SEQ ID NO:

• 4, wherein said cysteine-rich binding domain polypeptide consists of an amino acid sequence of about 50 to about 616 residues comprising cysteine residues that are in substantially similar relative positions as positions of cysteine residues in an amino acid sequence of a P. vivax Duffy Antigen binding protein of SEQ ID NO:
• 2, in an amount sufficient to induce a partial protective immune response that reduces the severity of infection by Plasmodium falciparum merozoites in an organism.

A method of inducing a partially protective immune response to Plasmodium falciparum merozoites in a patient, the method comprising administration to the patient of an immunologically effective amount of a pharmaceutical composition comprising a pharmaceutically acceptable carrier and an isolated cysteine-rich binding domain polypeptide derived from a P. falciparum 175 kDa sialic acid binding protein of SEQ ID NO:4 wherein the cysteine-rich binding domain polypeptide consists of an amino acid sequence of about 50 to about 616 residues comprising cysteine residues that are in substantially similar relative positions as positions of cysteine residues in an amino acid sequence of a Duffy Antigen binding protein of P. vivax of SEQ ID NO:2, wherein the partially protective immune response reduces the severity of infection by P. falciparum.

A method of inducing a partially protective immune response to Plasmodium vivax merozoites in a patient, the method comprising administration to the patient of an immunologically effective amount of a pharmaceutical composition comprising a pharmaceutically acceptable carrier and an isolated cysteine-rich binding domain polypeptide derived from a P. vivax Duffy Antigen binding protein of SEQ ID NO:2, wherein the P. vivax cysteine-rich binding domain polypeptide consists of an amino acid sequence of about 50 to 325 residues comprising cysteine residues in substantially similar relative positions as positions of cysteine residues present in a P. falciparum 175 kDa sialic acid binding protein of SEQ ID NO:

• 4, and wherein the partially protective immune response reduces the severity of infection by P. vivax.

A method of inducing a partially protective immune response to Plasmodium falciparum merozoites and Plasmodium vivax merozoites in a patient, the method comprising administration to the patient of an immunologically effective amount of a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a combination of an isolated first cysteine-rich binding domain polypeptide derived from the P. falciparum 175 kDa sialic acid binding protein of SEQ ID NO:4, wherein the first cysteine-rich binding domain polypeptide consists of an amino acid sequence of about 50 to about 616 residues, and an isolated second cysteine-rich binding domain polypeptide derived from P. vivax Duffy Antigen binding protein of SEQ ID NO:2, wherein the second cysteine-rich binding domain polypeptide consists of an amino acid sequence of about 50 to about 325 residues, and wherein the first cysteine-rich binding domain polypeptide comprises cysteine residues that are in substantially similar relative positions as positions of cysteine residues present in the amino acid sequence of the second cysteine-rich binding domain polypeptide, and wherein the partially protective immune response reduces the severity of infection by P. falciparum and P. vivax.