Figure 2. Aerosol transmission of H9N2 and H3N2 viruses.

Ferrets were inoculated i.n. with 10⁶ TCID₅₀ of RGWF10 or RGMemphis98 virus. Twenty-four hours later, one naïve ferret was added to each infected ferret to serve as direct contact, and another ferret was placed into an adjacent cage separated by a wire mesh to serve as aerosol contact. Nasal washes were collected daily and were titrated in MDCK cells. (A) RGWF10 infected and direct contacts. (B) RGWF10 aerosol contacts. (C) RGMemphis98 inoculated and direct contacts. (D) RGMemphis98 aerosol contacts.