Figure 5. Heterologous immunity.

To assess for cross-protection, different strains of mice including A/J [H-2^a], B6 [H-2^b] and BALB/c [H-2^d] mice were immunized with 10³ (AS) prbc and challenged i.v. with homologous (AS) or heterologous (AJ or YM) parasites at 2, 8, or 12 weeks after vaccination. Rechallenge was performed at 12 weeks after parasite clearance. The outcome of infection was monitored by assessing parasitemia. Data for individual mice are shown. nd, not determined. ^†Animals that succumbed to infection.