Pathogenicities of H5N1 HPAIVs for chickens, ducks, and mice.

<p>Eight chickens of each group were intravenously infected with 10⁶ PFU of 2 original isolates (WZ83 and WZ101) (A). Eight chickens of each group were intravenously infected with 10⁶ PFU of plasmid-derived viruses (rgWZ83, rgWZ101, rgWZ-83PB1/101M, and rgWZ-83M/101PB1) and observed for clinical symptoms every 8 hours (B). Six chickens of each group were intranasally infected with 10⁶ PFU of each virus and observed for clinical symptoms every 24 hours (C). Five ducks of each group were intranasally infected with 10⁶ PFU of rgWZ83, rgWZ101, rgWZ-83PB1/101M, or rgWZ-83M/101PB1 and observed for clinical symptoms every 12 hours (D). Three mice of each group were intranasally infected with one of 4 infectious doses (10, 10², 10³, or 10⁴ PFU) of each virus, and MLD₅₀ was calculated (E).