Evaluation of cytokine pattern of diphtheria-tetanus vaccine in laboratory animal model

Due to universal vaccination program, the prevalence of many dangerous diseases among infants and adults has been significantly reduced. In order to obtain appropriate strategies for regulating immune responses that lead to increased vaccine efficacy, here we investigated the pattern of immune response following diphtheria-tetanus vaccine administration in mice model. Diphtheria (D) and tetanus (T) monovalent and divalent (DT) vaccines have been separately formulated in the presence and absence of adjuvant (aluminum phosphate gel). Each vaccine has been injected for 5 times in Balb/c mice.  Two weeks after the last injection, the spleen of the mice was removed and the spleen cells were exposed to the selected antigens and the levels of Interleukin 4 (IL-4) and IFN- ɤ (Interferon gamma) were measured in cell culture supernatant. According to our results, the levels of IL-4 was significantly increased in mice receiving adjuvant vaccines compared with the non-adjuvant and control groups, while this increase was not significant for IFN-Ƴ. This results mentioned that the orientation of immune responses is more towards T helper 2 responses (Th2), which could be related to the nature of the antigen, the vaccine formulation strategy and the percentage of antigen uptake in the alum gel.