Figure 2.

Vi-polysaccharide and Vi-conjugate vaccines provide equal protection against infection with Vi+ S. Typhimurium. (A) Colony forming units (CFU) in the spleen of C57Bl/6 mice immunized i.p with 2 µg Vi-PS, Vi-CRM₁₉₇, Vi-TT or PBS mice, then infected for 72 hours with 1x10⁵ CFU Vi+ S. Typhimurium TH177 14 days later. Data pooled from 2 experiments with n = 4 mice/group. (B) Spleen CFU of immunized i.p with either 4 µg of Vi-PS or Vi-TT at day 0, or 2 µg each vaccine at both day 0 and 35 (boost groups), then infected with 1x10⁵ CFU TH177 day 41, for 72 hours. Data pooled from 2-3 experiments with n = 2 or 4 mice/group. *p≤0.05, **p≤0.01, ***p≤0.005 and ****p≤0.001 by Kruskall Wallace one-way ANOVA with Dunn’s multiple comparisons between groups (two-tailed).