Figure 1.
BALB/c mice infected with low doses of Leishmania major induced a protective response to the disease. Groups of mice (n = 6–10 per group) were infected in the left hind footpad with 1 × 102 (□), 1 × 103 (○), 1 × 104 (+), 1 × 105 (▪) or 1 × 106 (•) L. major, and C57BL/6 mice were also infected with 1 × 106 parasites (◊) as a control for the protective response. The weekly measurements of footpad thickness represent the average score ± standard error of the mean (SEM) of at least six mice per group. *P<0·001 for the group of mice infected with 1 × 102 L. major compared to mice infected with 1 × 106 parasites 10 weeks postinfection, based on Dunnett's t-test.