Induction of PspA-specific systemic and respiratory antibody responses by intranasal immunization with PspA-C-CPE.

<p>Mice were nasally immunized with vehicle, PspA alone, or PspA-C-CPE (PspA; 5 μg) once weekly for 3 weeks. One week after the last immunization, PspA-specific serum IgG (A), nasal IgA (B), BALF IgG (C), and IgA (D) were measured by ELISA. Data are shown as mean ± SEM and are representative of two independent experiments. Vehicle, n = 4; PspA, n = 5; PspA-C-CPE, n = 5. Values were compared by using the non-parametric Mann–Whitney <i>U</i> test. *<i>P</i> < 0.01.