FIG. 9.

B. pertussis colonization in trachea and lung following intranasal infection. Six mice were immunized with four doses of 5 × 10⁸ CFU of either IEM101 or IEM101(pNIR-tcf). At day 70, mice were challenged intranasally with 10⁶ CFU of BP18323. Fourteen days after challenge, the mice were sacrificed and colonization in lungs and tracheas was determined. Results are expressed as geometrical means of bacterial counts. Values are significantly different, with a P of <0.03. NS, values not significantly different.