The Immunogenicity of the C Fragment of Tetanus Neurotoxin in Production of Tetanus Antitoxin

The demand of tetanus antitoxin (TAT) as tetanus treatment in developing and underdeveloped countries is still great since it is relatively easy to achieve and affordable. However, there are still issues in the preparation of highly effective TAT with tetanus toxoid (TT) as the immunogen. The tetanus toxin native C-fragment (TeNT-Hc) retains many properties and it is a very promising candidate for the development of tetanus human vaccine. In this study, we tested the immunogenicity of TeNT-Hc in the preparation of tetanus antibodies, by TeNT-Hc alone or in different combinations with TT. The antibody titers and components in horse serum or plasma in different groups were analyzed and compared with those immunized by the conventional TT and it showed comparability with the results of traditional methods. The plasma efficacy and in vivo tetanus toxin neutralization were also tested. After two stages of immunizations, the average potency in plasma of all groups reached more than 1,000 IU / mL except that in group 4. In group 5, the first two basic immunizations with TT and the subsequent immunizations with TeNT-Hc, it showed slightly higher antibody titers and potency. This study demonstrated that TeNT-Hc is a safe, effective, and yet easy-to-produce low-cost immunogen and suitable for TT replacement in tetanus antitoxin production.