Abstract: 　AIM: To analyse the humoral immune response in mice to nucleic acid vaccines ( VR1012/HG MSP1 17 for intracellular expression or VR1012/TPA/HG MSP1 17 for secretion) containing Plasmodium falciparum merozoite surface protein 1 (MSP1) 17 block gene and gene fragment of several T cell epitopes from MSA1, MSA2, RESA, IL 1 and TT. METHODS: BALB/c or C 57 BL/6 mice received three times intramuscular immunization with 200 μg/100 μl or 100 μg/100 μl of VR1012/HG MSP1 17 or VR1012/TPA/HG MSP1 17 per mouse each time. Anti HG or anti MSP1 17 antibodies were monitored by indirect ELISA. RESULTS: BALB/c and C 57 BL/6 mice immunized with 100 μg/100 μl of VR1012/HG MSP1 17 per mouse raised significantly anti HG and anti MSP1 17 antibodies, but the levels of antibodies were not high. BALB/c mice immunized with 200 μg/100 μl of VR1012/HG MSP1 17 per mouse raised higher anti HG antibodies but not anti MSP1 17 antibodies. BALB/c mice immunized with 200 μg/100 μl of VR1012/TPA/HG MSP1 17 per mouse raised low level of anti HG antibodies only. CONCLUSION: VR1012/HG MSP1 17 is more immunogenic than VR1012/TPA/HG MSP1 17.

Key words: Plasmodium falciparum, nucleic acid vaccine, merozoite surface protein 1