Moreover, no differences in fluke burdens, fecal egg counts, humoral response (specific IgG1 and IgG2), and cell-mediated immune response (IFN-γ production) were reported in calves challenged with F. hepatica after single or trickle infection (48, 57, 75) suggesting that reinfections do not induce protection. The gene discussed is IFNG; the disease is infection.