PspA-C-CPE-mediated induction of protective immunity against pneumococcal infection.

<p>Mice were nasally immunized with vehicle, PspA alone, or PspA-C-CPE (PspA; 5μg) once weekly for 3 weeks. One week after the last immunization, mice were intrarespiratory challenged with <i>S</i>. <i>pneumoniae</i> (5.0 × 10⁶ CFU/mouse), and their survival was monitored for 14 days. Survival was compared between groups by using the non-parametric Mann–Whitney <i>U</i> test. **<i>P</i> < 0.05, *<i>P</i> < 0.01. Data were collected four experiments. Vehicle, n = 35; PspA, n = 45; PspA-C-CPE, n = 59.