BALB/c mice were immunized and challenged as indicated in Figure 1. Tissues were then harvested 7 days post-challenge, fixed with paraformaldehyde, paraffin embedded, sectioned, and stained with H&E. In this figure we show lung samples of a normal un-immunized and un-challenged mouse (A), a PBS-immunized and challenged mouse (B), a mouse immunized with iFt alone and challenged (C) and a mouse immunized with iFt plus CTB and challenged (D). All samples are at 20X magnification. Reduced tissue pathology was observed in the iFt plus CTB-immunized mice.