Fig. 1.
Respiratory droplet transmissibility of H3N2 and H5N1 viruses. Three ferrets were inoculated with 104 FID50 of Pan99 (A), Vic75 (B), HK486 (C), or 106 EID50 of HK213 (D), and nasal washes were collected from each ferret on alternating days for at least 5 days p.i. (Left). Twenty-four hours after inoculation, a naive ferret was placed in each of the adjacent cages with adjoining perforated walls that only allowed transfer of virus between ferrets through the air. Nasal washes were collected from the contact ferrets on alternating days for at least 7 days p.c. (Right). Solid, dotted, and hatched bars each represent a separate ferret pair. The limit of virus detection was 101.5 EID50/ml.