Figure 1.
Mean antisporozoite antibody titers of C3H, B6, and BALB/c mice immunized with WSN/PfB1. Immunofluorescence titers of the pooled sera of each group of mice were determined at the times indicated. After receiving the immunizing doses (indicated by arrows), the mice were bled monthly. Most mice received a first i.n. dose of 3 × 105 pfu followed 2 weeks later by the same i.n. dose and a third i.p. injection of 10 μg of the purified virus (C3H mice, •; B6, ▿; BALB/c, ▾). Two BALB/c mice received a single immunizing dose of WSN/PfB1 (□). B6 control mice received a single immunizing dose of WSN ▪.