TABLE 2.

Virus titers in the respiratory tracts of ferrets inoculated with NL602, NL602/PB2-627K, NL602/PB2-677G, and NL602/PB2-701N viruses

TissueVirus titer (log10 TCID50/g tissue)a
3 days p.i.7 days p.i.
NL602NL602 627KNL602 677GNL602 701NNL602NL602 627KNL602 677GNL602 701N
NT6.9 ± 0.3 (3/3)7.2 ± 0.6 (3/3)6.8 ± 0.5 (3/3)6.7 ± 0.6 (3/3)4.4 ± 0.7 (2/3)ND6.8 (1/3)4.9 ± 1.3 (3/3)
Trachea5.0 ± 0.7 (3/3)4.4 ± 1.0 (3/3)5.3 ± 0.5 (2/3)5.1 ± 1.0 (3/3)2.4 (1/3)NDND2.1 (1/3)
Lung5.6 ± 0.9 (3/3)5.4 ± 0.7 (2/3)4.8 ± 0.3 (2/3)4.9 ± 1.1 (3/3)1.5 (1/3)NDNDND
  • a Geometric mean titers of positive samples ± standard deviations are given, and the numbers of positive animals are indicated in parentheses. ND, not detected. The detection levels for nasal turbinates (NT), trachea, and lung were <1.5, <1.5, and <1 log10 TCID50/g tissue, respectively.