Figure 1: The geometric mean values of IgG titer to F1 were derived from ten serum samples per group. DV stands for dry vaccine and LV for liquid vaccine; the numbers following DV or LV represent concentration of 20, 10 and 5µg of F1 antigen in a final volume of 100µl, respectively. Standard deviation (SD) corresponding to the groups of DV20, DV10, DV5, LV20, LV10 and LV5 was 1.6, 2.1, 2.5, 1.6, 2.3 and 2.5, respectively.