Each patient will be vaccinated with 5-10 mL of P. vivax-infected red blood cells containing approximately 1 × 10^8 Plasmodium parasites. After vaccination, the onset and duration of peripheral parasitemia and the infection rate will be observed. Once the infection rate reaches 0.1%, 10-30 mL of venous blood will be drawn, tested, and frozen to preserve the blood with parasitemia (to ensure that except for P. vivax, all other parameters meet the blood donation standards), which will be used to vaccinate subsequent patients.