TABLE 2.
Pathogenicity of chimeric HA viruses in micea
| Virus | Mean virus titer ± SD
|
Mean change in body wt (%) ± SD
|
% dead (no. dead/8 tested) | ||
|---|---|---|---|---|---|
| Nasal turbinates | Lungs | Day 5 | Day 14 | ||
| Wild type | |||||
| A/WSN-R | 5.0 ± 0.3 | 8.2 ± 0.1 | −27.4 ± 1.1 | NAb | 100 (8) |
| B/Lee-R | 4.7 ± 0.1 | 5.6 ± 0.1 | −19.3 ± 7.9 | (−11.7) | 87.5 (7) |
| Chimeric | |||||
| ANSBH | 4.0 ± 0.3 | 2.8 ± 0.3 | 2.6 ± 1.0 | 4.6 ± 1.2 | 0 (0) |
| ANTBH | 5.3 ± 0.3 | 4.9 ± 0.1 | −17.3 ± 0.7 | −8.3 ± 0.4 | 0 (0) |
| ANSTBH | 5.3 ± 0.4 | 4.6 ± 0.1 | −20.9 ± 0.3 | −6.2 ± 8.8 | 0 (0) |
| Control (PBS) | NA | NA | 2.9 ± 1.3 | 7.1 ± 0.2 | 0 (0) |
a
Mice were intranasally inoculated with virus (105 TCID50) and monitored for 14 days. Virus titers were determined as log10 TCID50/g at 3 days postinoculation and reported as means ± standard deviation (n = 3). Changes in body weight are reported as means ± standard deviations (n = 3). The data in parentheses are from one mouse. Control mice were mock inoculated with phosphate-buffered saline (PBS).
b
NA, not applicable.