Vaccine potential of recombinant cathepsin L1H against Fasciola gigantica infection in goat.

Cathepsin L1H has been identified as a potential vaccine candidate against fasciolosis. The present study was conducted to evaluate the immunoprophylactic efficacy of recombinant proFgCatL1H (rproFgCatL1H) antigen in goats subsequently challenged with the parasite. Immunization of goats with 200 µg of rproFgCatL1H formulated in Montanide™ ISA 61 VG conferred statistically significant reduction in worm recovery compared with both the infected control and adjuvant control groups, corresponding to reductions of 37.55 % and 34.07 %, respectively (p < 0.05). A negative correlation was observed between worm burden reduction and serum IgG levels (OD₄₅₀), measured both at the time of infection and at the study endpoint, although the association was not statistically significant. Scanning Electron Microscopy (SEM) analysis of adult F. gigantica recovered from vaccinated goats demonstrated pronounced tegumental damage, characterized by extensive swelling, surface erosion, and the presence of cell-like structures adhering to the tegumental surface. These findings suggest that the recombinant protein rproFgCatL1H holds promise as a potential vaccine candidate for the control of fasciolosis in goats.