Figure 6.

Increased Francisella tularensis (Ft)-specific antibody production is induced by inactivated Ft (iFt)-Mueller Hinton Broth (MHB) versus iFt-Brain-Heart Infusion (BHI). Mice were immunized twice at a 3-week interval with 20 µl phosphate-buffered saline (PBS) or 150 ng of iFt-BHI or iFt-MHB via the intranasal route in 20 µl PBS. Sera obtained 2 weeks postboost were analyzed for Ft-MHB-specific (A) and Ft-BHI-specific (B) IgG. Values represent mean ± SE of two independent experiments (n = 16 mice per group). *p < 0.05.