Mice were challenged 2 weeks after the last immunization. They were imaged five days after they had been challenged with 10,000 Pru (Fluc) using a Xenogen in vivo imaging system. As shown in the initial experiment in Figure 7b , the numbers of luciferase expressing parasites in immunized HLA-A*1101 mice were significantly reduced compared to the numbers of parasites in unimmunized mice. Results 