CPQ and infection: For adult worms, we also demonstrated that intestinal aminopeptidase activity could be markedly inhibited by the same IgG antibodies from immunoprotected goats compared with respective controls (Figures 8A, B), and that inhibition levels were correlated with the reductions in H. contortus egg numbers in faeces and infection intensity (R2 of 0.98 and 0.96 respectively; Figures 8C, D).