Figure 4

Protection study 1. Fourteen CD1 outbred mice per group were immunized in a prime-boost regimen with DNA and vaccinia vectors that express PY03011, PY03424 or PY03661, or a combination of vectors that express all three P. yoelii antigens. Positive control mice were immunized with DNA and vaccinia vectors that express PyCSP. Negative control mice were immunized with DNA and vaccinia vectors that do not express a P. yoelii antigen. Groups are designated (dose = 1X) or (dose = 3X) to represent the relative quantity of the DNA and vaccinia vectors that they received. The mice were challenged with 300 P. yoelii sporozoites and evaluated for parasitaemia by examining Giemsa-stained blood smears.