Figure 1

Clinical signs of challenge with H5N1 virus A/VN/1203/04 in ferrets. 6 ferrets (donors) were infected with 1 × 10^2.6 EID50/ml (low dose) of virus and 6 other donors were infected with 1 × 10^3.6 EID50/ml of virus. For each challenge dose, the donor animals were divided into two groups; blood was collected on days 2 and day 6 post-infection from one of these groups and on days 4 and day 10 post-infection (or the day before animal died) from the other group. At these time points about 2 ml of freshly collected blood was transfused into its appropriate recipient. (A). Survival of ferrets after challenge. Ferrets (donors) were inoculated with either low dose or high dose of the virus and animal survival was recorded up to 12 days post-challenge. (B) Ferrets (recipients) were transfused with blood collected from donor animals on days 2, 4, 6, and 10 post-infection, or on the day the donor animal died; survival was recorded up to 12 days post-transfusion.