Comparative evaluation of antibody response in rabbits vaccinated with toxoid

Aim: To compare the newly formulated enterotoxaemia vaccine having oil and alum adjuvants, with presently available toxoid and alum precipitated vaccines. Materials and Methods: Three types of enterotoxaemia vaccines, namely toxoid (TV), alum precipitated (APV) and alum precipitated oil adjuvant vaccine (AOV) were prepared using a highly toxigenic strain of Clostridium perfringens type D procured from Division of Biological Standardization, IVRI, Izatnagar. Humoral immunity generated in rabbits with these vaccines was then quantified using indirect enzyme-linked immunosorbent assay (ELISA) and mice neutralization test (MNT). Results: Out of three enterotoxaemia vaccines tested, alum precipitated oil adjuvant vaccine produced higher and persistent antibody titre for more than 45 days without any booster dose and did not produce any untoward reactions at the injection site. Alum precipitated vaccine elicited better and persistent immune response than toxoid vaccine though it was less than alum precipitated oil adjuvant vaccine. In MNT, alum precipitated and alum precipitated oil adjuvant vaccines showed protection at th th 45 day of post vaccination while toxoid vaccine showed only up to 28 day. Conclusion: Results of the study unfolded the synergistic role of adjuvants in the induction of better and persistent immune response and also indicated the superiority of alum precipitated oil adjuvant vaccine over the currently available toxoid and alum precipitated enterotoxaemia vaccines.