Effect of immunization with the combination of Vaxfectin and MCSP DNA on protection achieved against <i>in vivo</i> challenge with <i>P. yoelii</i> sporozoites.

<p>C57BL/6 mice were immunized with the indicated DNA vaccine or irradiated sporozoites as described in the Methods section. Two weeks after the final immunization, mice were challenged with 5×10³<i>P. yoelii</i> 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 (horizontal lines). The MCSP/Vaxfectin or irradiated sporozoite groups differed significantly from any other group (p<0.002), but not from each other (p>1.000).