TABLE 1 .
Characteristics of viruses evaluated in this study
| Name | Genotype | Nadir wt (% of baseline) | Lung titer (PFU/g) |
Histopathology | |
|---|---|---|---|---|---|
| 3 dpi | 5 dpi | ||||
| rNY312 | NY312 | −0.62 | 2.6 × 103 | 2.7 × 103 | Few inflammatory foci; very rare viral antigen |
| rNY312-K627E | NY312, PB2-K627E | −0.57 | 4.1 × 103 | 3.5 × 103 | Few inflammatory foci; very rare viral antigen |
| 1918RNP | 1918RNP:NY312 | −15.9 | 7.7 × 105 | 6.5 × 105 | Moderate-marked necrotizing bronchiolitis; abundant bronchiolar viral antigen |
| 1918RNP-K627E | 1918RNP, PB2-K627E:NY312 | +0.54 | 4.4 × 104 | 2.6 × 105 | Few inflammatory foci; minimal bronchiolar viral antigen |
| VN1203RNP | VN1203RNP:NY312 | −15.7 | 4.2 × 105 | 2.6 × 103 | Moderate-marked necrotizing bronchiolitis; abundant bronchiolar viral antigen |
| S09RNP | S09RNP:NY312 | −4.93 | 5.2 × 104 | 1.4 × 102 | Focal alveolitis; predominantly alveolar viral antigen |
| S09RNP-E627K | S09RNP, PB2-E627K:NY312 | −8.06 | 9.9 × 105 | 2.3 × 105 | Mild bronchiolitis; moderate bronchiolar viral antigen |
| CA09RNP | CA09RNP:NY312 | −4.18 | 2.2 × 105 | 4.1 × 104 | Mild, focal necrotizing bronchiolitis; low levels of bronchiolar viral antigen |
| CA09RNP-E627K | CA09RNP, PB2-E627K:NY312 | −0.83 | 1.1 × 103 | 4.3 × 102 | Few inflammatory foci; very rare viral antigen |
| CA09RNP-D701N | CA09RNP, PB2-D701N:NY312 | −1.71 | 1.2 × 104 | 2.5 × 103 | Few inflammatory foci; very rare viral antigen |