Figure 9. Protective efficacy of different vaccine constructs in C57BL/6 mice challenged with transgenic P. berghei expressing P. falciparum CSP.

C57BL/6 mice were immunized with 5 µg of the indicated DNA vaccine as described in the Methods section. Two weeks after the final immunization, mice were challenged with 5×10³ transgenic P.berghei sporozoites, and parasite-specific rRNA levels in the liver were determined by quantitative RT-PCR on samples obtained 48 hours post challenge. All results were normalized against the expression of actin. Results indicate the copy numbers from individual mice (closed squares) and the mean from the 5 mice in each group (lines). ** Compared to hMfCSP/Vaxfectin p<0.001. *Compared to hMfCSP/Vaxfectin p<0.05. No other differences among groups were statistically significant.