A field trial of oil adjuvanten trivalent Actinobacillus pleuropneumoniae vaccine.

The trivalent vaccine of A. pleuropneumoniae serotype 1, 2 and 5 (AP3V) was prepared in the oil-in-water type adjuvanten form. At an SPF farm, the vaccinated pigs were observed for their antibody response, finishing rate, and lung lesions at the time of slaughter and for injection scars. The CF titers against serotype 1, 2 and 5 started to rise after the second injection, showed the highest titer at 30 days after injection and then gradually decreased in vaccinated pigs. The finishing rate in the vaccinated group was 91.6% and that in the control group immunized with commercial vaccine was 60%. The lungs in the control pigs showed severe pneumonia with hyperemia, pleural adhesion and abscess. In contrast, vaccinated pigs showed slight pneumonia. Injection scars were not observed in vaccinated pigs 100 days after the second injection. In conclusion, the pigs immunized with AP3V were sufficiently protected against A. pleuropneumoniae infection and the trial proved to be satisfactory in the safety of the vaccine under field conditions.