Supporting Information

Files in this Data Supplement:

Fig. 1. Titers of A/mallard/Vietnam/16D/03 (H5N1) virus shed during the course of infection. Two mallard ducks were inoculated with 10⁶ 50% egg infectious doses (EID₅₀) of A/mallard/Vietnam/16D/03 (H5N1) influenza virus, and 4 hours later two contact ducks were placed in the cage with the inoculated ducks. The ducks were observed over a period of 21 days. Tracheal and cloacal swabs were collected every other day, beginning on day 3 after inoculation. The figure shows the viral titers detected on the indicated days. Titers from the two inoculated birds and the two contact birds were averaged for the day-3 time point. Both of the contact birds and one inoculated bird died on day 4 after inoculation.

Fig. 2. Sequence data chromatograms of the hemagglutinin (HA) gene of A/VN/3046/04. The original stock virus and virus isolated from ducks at day 7 and day 11 after infection of A/VN/3046/04 was sequenced by using H5 specific primers. (A) The original stock virus. (B) Virus isolated on day 7 after infection. (C) Virus isolated on day 11 after infection. The original stock virus HA sequence shows base peaks under peaks. By day 7 after infection, the minor base peaks are becoming more dominant in the virus mixture (two bases indicated by asterisks). By day 11 after infection, the minor constituent of the stock virus mixture becomes the dominant sequence.