Evaluation of the efficacy of a Clostridium perfringens type A toxoid vaccine for pigs using a toxin challenge model and under field conditions

The objective of the trials was to test the efficacy of a Clostridium perfringens type A toxoid vaccine with a toxin challenge model and under field conditions according to Regulation (EU) 2019/6.15 gilts were vaccinated twice at 5 and 2 weeks before the 1st and once more 2 weeks before the 2nd parturition. Antibodies against the alpha and beta2 toxins were determined in the serum and colostrum of gilts and in the serum of piglets. At 2 days of age (after 1st parturition), piglets were challenged intra-abdominally with an alpha and beta2 toxin-containing supernatant of a heterologous Clostridium perfringens type A strain. The piglets were examined clinically and euthanized animals pathologically after the challenge.In a field trial, 18 gilts were vaccinated twice with the same vaccine. Antibodies against the toxins in serum and colostrum of gilts were determined and mortality and incidence of diarrhea in piglets up to 26 days of age were monitored.The vaccination elicited antibodies against the alpha and beta2 toxins, which were transferred to the offspring by the uptake of colostrum. Piglets were significantly protected from clinical signs and mortality by the antibodies after receiving an intra-abdominal toxin challenge. A 3rd vaccination at 2 weeks before 2nd farrowing led to a further significant increase of antibodies in colostrum of the second parity sows and in serum of the piglets compared to basic vaccination. Vaccination under field conditions resulted in a significant increase of antibodies and a significant reduction in the incidence of diarrhea in piglets.</p