Vaccination of calves against Cooperia oncophora with a double-domain activation-associated secreted protein reduces parasite egg output and pasture contamination

Vlaminck J., Borloo J., Vercruysse J., Geldhof P., Claerebout E., 2015. Vaccination of calves against Cooperia oncophora with a double-domain activation-associated secreted protein reduces parasite egg output and pasture contamination.

International Journal for Parasitology 45, 209-213; doi: 10.1016/j.ijpara.2014.11.001

Two vaccination trials were performed to test a protein purified from the small intestinal parasite Cooperia oncophora as a vaccine antigen against this parasite. In a first experiment, calves were vaccinated three times with ASP, and subsequently challenged with an artificial infection of C. oncophora infective larvae. Vaccinated calves shed 91 % less worm eggs in their faeces than control calves, indicating that the vaccine was highly effective in experimental conditions.

Therefore, the vaccine antigen was further evaluated under field conditions. Calves were immunised as described above, followed by a natural challenge infection on pasture. Worm egg counts in the vaccinated animals were strongly reduced during the entire grazing period, resulting in a lower infectivity of the pasture and a reduction of 81.6 % in total numbers of C. oncophora worms in the vaccinated group at the end of the grazing season.

Taken together, these results highlight the protective capacity of the tested antigen and the possibility of controlling C. oncophora infections through vaccination.