FIG 5.

Chicken-to-ferret interspecies transmission efficiency. Naive ferrets were exposed to SPF chickens inoculated or infected with chicken (SCk1772) (A) or human (HK3263) (B) H7N9 virus. Ferret nasal washes were collected every other day and titrated in MDCK cells (log₁₀TCID₅₀ per milliliter) to monitor chicken-to-ferret transmission via the airborne route (A and B). Genotyping of V/K/E at PB2 residue 627 in nasal washes collected from ferrets infected by SCk1772 and HK3263 was also conducted (C).