Figure 3.

Protective capacity of CTB-Fim2. Groups of animals were immunized (a) intraperitoneally or (b) intranasally three times with PBS, CTB (IN only), rFim2, BpFim2, or CTB-Fim2 every 12 days followed by IN challenge with 5 × 10⁷ UFC of the Tohama I strain of B. pertussis. At 8 days postinfection, animals were killed and lung samples were collected for UFC counting. Each point represents the mean (± standard error) of 8 animals (**P < 0.001 versus PBS; ***P < 0.0001 versus PBS, CTB, and rFim2).