Figure 4

Antibody responses in mice. Serum IgG responses to SaoA (A) or to Eno (B) and vaginal IgA responses to SaoA (C) or to Eno (D) were measured by ELISA. The data represent reciprocal antibody titers in sera from ten mice orally immunized with attenuated Salmonella carrying either pS-SaoA, pS-Eno, pS-SE, or pYA3493 (empty vector) and PBS 3 weeks after the first immunization and 2 weeks after boosting. Serum and vaginal wash obtained from individual mice were serially diluted to obtain titers, starting from either 1:50 or 1:10. Error bars represent variation between mice. ns not significant, *P < 0.05; ***P < 0.001. No antibody responses were detected to antigen tested in mice immunized with only PBS or in pre-immune sera from vaccinated mice. ELISA was performed twice with identical results.