Figure 4.

Vaccine efficacy in a S. pneumoniae nasopharyngeal colonization model. Mice were immunized intranasally with adjuvanted dPly or adjuvant alone (control) before they were intranasally challenged with either the pneumococcal strain 6B/CDC, 2D39 or 4/CDC. Bacterial colonies in nasal washings were counted at day 2 and at day 4 (day 6 for 4/CDC) post-challenge and expressed as log₁₀ mean CFU. Each dot represents a mouse. Dashed lines indicate the limit of detection (at 0.70); Black horizontal bars are geometric means. Statistical analyses were carried out per day with ANOVA. All significant differences, compared with the control, are shown. ***, P< 0.001, n.s., not significant.