USP45 and brucellosis: We hypothesized that the co‐administration of immunomodulatory cytokines and antigens would boost the immunogenicity of the fusion protein (romp25–Usp45) and the efficacy of our constructed vaccine when Usp45 was expressed as an omp25 secretion factor of B. abortus in the future in vivo study on the topic of vaccination against brucellosis.