Cattle and rabbits immune response against beta and epsilon Clostridium perfringens toxins induced by six commercial vaccines in Brazil

The antibody response against beta and epsilon toxins of Clostridium perfringens was evaluated in cattle vaccinated with six commercial clostridial vaccines. Groups of six calves (6-7 months old) were vaccinated with each vaccine (T2 to T7), on days 0 and 42, with the recommended dose and route. Saline solution (T1) and a standard toroid vaccine (T8) were used as negative and positive controls, respectively. On days 0, 42 and 56 post-vaccination (PV), blood samples were collected for antibody titration. Vaccines, as well as controls, were also injected into 8 rabbits each, on days 0 and 21, using half of the dose recommended for cattle. Rabbits were bled on day 35. Rabbit sera were rested as a pool per vaccine and cattle sera were tested individually against beta and epsilon toxins, by the serum neutralization test in mice. The vaccine T2 had antibody titers of 22.6 and 5.6 IU/ml and T4 had 11.2 and 7.0 IU/ml against beta and epsilon toxins in rabbits, respectively. The standard toroid had a titer of 45.2 IU/ml against both toxins. In cattle, mean antibody titers against beta toxin on days 42 and 56 PV induced by T2 (1.15 and 8.0 IU/ml) were similar to those induced by the standard toroid (2.02 and 10.3 IU/ml). T4 titers (0.73 and 4.54 IU/ml), were lower (P < 0.05) than those obtained with the standard toroid, but similar to T2 titers. On day 42, the standard toroid had a mean titer (0.97 IU/ml) against epsilon toxin significantly higher (P < 0.05) than that obtained,vith T4 (0.15 IU/ml) but similar to T2 mean titer (0.42 IU/ml). On day 56 T2 resulted in a significantly higher titer (4.27 IU/ml) (P < 0.05) than that induced by T4 (0.68 IU/ml), bur similar to the standard control (4.98 IU/ml). The other vaccines, as well as the saline solution, did not elicit antibody responses, neither irt rabbits nor in cattle. T2 induced antibody titers against C. perfringens beta and epsilon toxins similar to those induced by the standard toroid and higher than those induced by T4.