FIG. 2.

Comparison of protective effect induced by different doses of dLOS-CRM conjugate in mouse lungs challenged with the M. catarrhalis strain 25238. Mice were i.n. immunized at 1-week intervals with one to five doses consisting of 10 μl of PBS containing a mixture of 5 μg of dLOS-CRM and 1 μg of CT or were kept as naïve mouse controls. One week after last immunization, all the mice were challenged (via aerosol) with 10 ml of M. catarrhalis strain 25238 (5 × 10⁸ CFU/ml) in a nebulizer, and their lungs were collected 6 h postchallenge. Bacterial recoveries from the lungs are expressed as geometric means + SD (error bars) from eight mice. Statistical significance for comparison with naïve mouse controls: **, P < 0.01; *, P < 0.05.