Table 2.
Viral Titers in the Respiratory Tract of PR8/PB2-PspA Virus–Immunized Mice Challenged With NC Virusa
| Immunization | Viral Titer, Mean (SD), log10 PFUs/g |
|
|---|---|---|
| Nasal Turbinates | Lungs | |
| Medium | 6.3 (0.4) | 6.1 (0.3) |
| PR8/PB2-GFP virus | 6.0 (0.4) | 4.0 (1.4)b |
| PR8/PB2-PspA virus | 5.9 (0.4) | 3.7 (1.3)c |
Abbreviations: GFP, green fluorescent protein; NC, A/New Caledonia/20/99; PFUs, plaque-forming units; PspA, pneumococcal surface protein A; SD, standard deviation.
a Mice were intranasally immunized 3 times with the indicated agents (50 µL) and challenged with NC virus (50 µL) 2 weeks after the final vaccination. Nasal turbinates and lungs were harvested from mice (n = 6) 3 days after challenge and subjected to virus titration by use of plaque assays in AX4/PB2 cells. Statistically significant differences in the viral titers compared with the medium (control) group were assessed using 1-way analysis of variance followed by a Dunnett test.
b P < .05.
c P < .01.