In vitro and ex vivo characterization of immune responses induced by tetanus and diphtheria toxoid vaccines that are produced as domestic and national products

In this thesis study, it was aimed to characterize the immune responses created by tetanus and diphtheria toxoid vaccines developed in the Gazi University Faculty of Medicine, Department of Immunology by using in vitro and ex vivo methods. These vaccines contain two different adjuvants; alum and calcium phosphate. Vaccines were administered in two different ways: subcutaneous (SC) and intraperitoneal (IP). The immune responses obtained with the developed and currently used adult type tetanus diphtheria vaccines were studied comparatively. After vaccination, mouse spleen mononuclear cells were analyzed by flow cytometry, and the amount of CD4 +, CD8 + and CD19 + cells were determined. It was found that mice in the IP-administered vaccine groups had higher CD4+ T cell and CD19+ B cell counts than the control group. The presence and concentration of IgG type anti-tetanus toxoid and anti-diphtheria toxoid antibodies were demonstrated by ELISA in vaccine administered mice both by SC and IP route. The protection and neutralizing properties of antibodies formed by vaccines containing alum adjuvant were demonstrated by the tetanus toxin challenge and diphtheria toxin in vitro neutralization tests. It was shown that the protection for tetanus toxoid was >99.9 % in both the commercial vaccine and the developed vaccine. When the neutralization capacity of anti diphtheria antibodies was evaluated, it was found that there was no difference between the commercial and the developed vaccine. Total protein amounts and Lf values of toxins used as vaccine antigen were determined. Antigenic purities were shown by SDS-PAGE and confirmed by Western Blotting. LD50 and PD50 doses for tetanus toxin determined in mice and MCD for diphtheria toxin in VERO-E6 cells were determined by MTT method.