FIG. 3.

Comparison of resistance to superinfection in WT and IL-5^−/− mice. Worm burdens in infected WT and IL-5^−/− mice were determined after perfusion. Mice received a primary infection (group A; four WT and six IL-5^−/− mice) primary and secondary infections (group B; five WT and five IL-5^−/− mice), or a secondary infection (group C; six WT and six IL-5^−/− mice). Resistance to reinfection was observed in both WT (61.4% ± 4.1%) and IL-5^−/− (53.6% ± 10.2%) mice in group B. Data are expressed as means ± standard errors. An asterisk indicates P < 0.05 compared with groups receiving a challenge infection alone.