Humoral immune responses. Five-week old female BALB/c mice were immunized with PBS, vector-only strain, and Salmonella secreting Brucella L7/L12. Humoral responses in serum and vaginal washes were measured on 14th day post-immunization. A Serum IgG response, IgA response in vaginal washes, and serum IgG1 and IgG2a were demonstrated. *Indicates significant difference compared to PBS control (P < 0.05). Probability values were depicted. B The IgG responses at 21st day post-immunization were measured against purified L7/L12 antigen, Brucella whole cell lysate and Salmonella whole cell lysate were conducted. ***Indicates the significant difference against the PBS control (P < 0.05).