Fig. 2. Mean nasal wash viral titer of wild-type and CVVs in ferrets.

Three ferrets per group were inoculated with 10⁶ PFU or EID₅₀ of virus (grey bars, wild-type virus; black bars, CVV). Nasal washes were collected on alternate days p.i. Mean titers for each group are shown as log₁₀ EID₅₀/ml + standard deviation (SD) with the exception of H7N9 viruses which are shown as log₁₀ PFU/ml. The limit of detection was 1.5 log₁₀ EID₅₀/ml or 1 log₁₀ PFU/ml. *, p < 0.05 between wild-type and CVV groups.