Figure 2.

The protective efficacy of formalin-inactivated H5N1 virus immunization is weakened during CHS. After CHS/TN and immunization, all the mice were challenged with PBS-diluted H5N1 virus (50 PFU). (a) The mortality of each group (n = 6 per group) was observed for 14 days after viral challenge. (b) Viral loads in the lungs at indicated days postinfection (n = 3 per group) were estimated by real-time PCR. Shown are representative results from three independent experiments. Statistically significant differences between the control and treated groups are indicated by ***(P < 0.001) and *(P < 0.05), respectively. (c) Representative lung sections from each group were stained with H&E. Solid arrows indicate interstitial oedema and inflammatory cellular infiltration about blood vessels, open triangles indicate dropout of mucous epitheliums and inflammatory cellular infiltration in bronchioles, open arrows indicate congestion, and solid triangles indicate thickening of the alveolar walls (scale bar = 100 μm).