AIM: To construct the recombinant Lactococcus lactis as oral delivery vaccination against malaria. METHODS: The C-terminal 19-ku fragments of MSP1 (MSP-119) of Plasmodium yoelii 265-BY was expressed in L lactis and the recombinant L lactis was administered orally to BALB/c and C57BL/6 mice. After seven interval vaccinations within 4 wk, the mice were challenged with P. yoelii 265-BY parasites of erythrocytic stage. The protective efficacy of recombinant L. lactis was evaluated. RESULTS: The peak parasitemias in average for the experiment groups of BALB/c and C57BL/6 mice were 0.8± 0.4% and 20.8±26.5%, respectively, and those of their control groups were 12.0±0.8% and 60.8±9.6%, respectively. None of the BALB/c mice in both experimental group and control group died during the experiment. However, all the C57BL/6 mice in the control group died within 23 d and all the vaccinated mice survived well. CONCLUSION: The results imply the potential of recombinant L lactis as oral delivery vaccination against malaria. AIM: To construct the recombinant Lactococcus lactis as oral delivery vaccination against malaria. METHODS: The C-terminal 19-ku fragments of MSP1 (MSP-119) of Plasmodium yoelii 265-BY was expressed in L lactis and the recombinant L lactis was administered After seven vaccinations within 4 wk, the mice were challenged with P. yoelii 265-BY parasites of erythrocytic stage. The protective efficacy of recombinant L. lactis was evaluated. RESULTS: The peak parasitemias in average for the experiment groups of BALB / c and C57BL / 6 mice were 0.8 ± 0.4% and 20.8 ± 26.5% respectively, and those of their control groups were 12.0 ± 0.8% and 60.8 ± 9.6% respectively. However, all the C57BL / 6 mice in the control group died within 23 d and all the vaccinated mice survived well. CONCLUSION: The results imply the potential of recombinant L lactis as oral delivery va ccination against malaria.