Pathological and parasitological protection in goats immunised with recombinant cathepsin L1 and challenged with Fasciola hepatica

Fluke burdens, faecal egg output and hepatic damage were assessed in goats immunised with recombinant cathepsin L1 (rCL1) plus Quil A (n = 7) or Quil A alone (control; n = 7) and challenged with Fasciola hepatica. There were no significant differences in fluke burdens (56 ± 26 vs. 92 ± 53), average fluke length (20.9 ± 3.0 vs. 21.0 ± 3.4 mm) or faecal egg output (525 ± 533 vs. 758 ± 677.8 eggs per gram at 17 weeks post-infection) between vaccinated and infected control groups, respectively, but high individual variability was evident. Morphometric and histopathological studies showed reduced hepatic damage in the vaccinated group compared to the infected control, but high individual variability was also recorded. Further vaccine trials in goats should be carried out using a larger number of animals to evaluate rCL1 as a vaccine for fasciolosis in goats.