FIG 5.

Vaccine efficacy in an NTHi nasopharyngeal colonization model. Mice were immunized intranasally with LT-adjuvanted PE, PilA, or PE-PilA or adjuvant alone (control) before they were intranasally challenged with NTHi strain 3224A. Bacterial colonies in nasal washings were counted on day 1 and day 2 postchallenge and expressed as the mean number of log₁₀ CFU. Each symbol represents a mouse. The dashed line indicates the limit of detection; the black horizontal bars are geometric means. Statistical analyses were carried out by two-way ANOVA. Groups were compared to each other over time (Tukey adjusted). P was <0.001 for the PE and PE-PilA groups versus the control group, P was equal to 0.9937 for the PilA group versus the control group, and P was equal to 0.4239 for the PE group versus the PE-PilA group. Representative results of 1 out of 4 experiments with either the 3224A or the 3219C NTHi strain are shown.