The Th2-skewed antibody profile in B6.TLR9−/−(OR) mice together with the inability of B6.TLR9−/−(OR) immune sera to affect primary parasitemia levels caused the impression that TLR9 liganding assists in the generation of a protective antibody profile essential for the acquisition of anti-malaria immunity. The gene discussed is TLR9; the disease is parasitic infectious disease.