Fig. 3

Expression levels of FimA-specific (a) and HA2-specific (b) secretory IgA antibodies in the saliva of SD rats at week 0–8, which were immunized with 100 ug of pVAX1 (group I), 100 ug of pVAX1-HA2-fimA (group II), 100 ug of pVAX1-HA2-fimA/IL-15 (group III), 100 ug of pVAX1-HA2-fimA+CpG-ODN 1826 (10 μg) (group IV), 100 ug of pVAX1-HA2-fimA+CpG-ODN 1826 (30 μg) (group V) and 100 ug of pVAX1-HA2-fimA+CpG-ODN 1826 (50 μg) (group VI), respectively. Asterisk represents a significant difference between group V and the other groups, respectively, *P < 0.05