Figure 7

Immunization with the combination of infectious virus and M2e-MAP. BALB/c mice were immunized twice (4 week interval) by the i.n. route with the components listed at the bottom of the figure. Dosage/injection (50 μl): M2e-MAP G39d (3 μg), ODN (3 μg), CT (0.5 μg), Vir (150–200 TCID₅₀ of PR8 for primary and of Seq14 for secondary immunization), Vir(uv) (5 μg of purified uv-inactivated PR8, <1 TCID₅₀). Plasma was collected three weeks after second immunization and pooled within groups. A. Ab titer measured by ELISA against M2e peptide (closed circles) and HeLa-M2 (open circles) in pooled plasma samples of groups of 3–4 mice from three independent vaccination experiments. Bars indicate the GMTs. The stipulated horizontal line indicates the threshold of detection of Ab titers against HeLa-M2. B, C, D. Four weeks after the second immunization, mice from two vaccination experiments were challenged by i.n. inoculation of 50 μl X31, which initiates an infection throughout the entire respiratory tract. Virus titers in nose, trachea and lung were determined three days later. Each symbol indicates the total virus titer (TCID₅₀) from an individual mouse in the nose (B), trachea (C) and lung (D). Bars indicate GMTs. The data were analyzed by non-parametric ANOVA and Dunn's Multiple Comparison Test. Statistical significance between experimental and control groups and between experimental groups is indicated by asterisks above each column and above two-sided arrows, respectively: p < 0.05 (*); p < 0.01 (**).