Body weight changes and lung virus titers in mice infected with H9N2 viruses.

<p>A) Groups of 4 mice were inoculated intranasally with 10⁷ EID₅₀ of QA23ML-3 Egg (black squares) or QA23 PP (open squares) viruses. Body weight and clinical signs of disease were monitored for 14 dpi. Data presented correspond to average body weight changes in each group with corresponding standard deviations. †, one mouse infected with the QA23ML-3 Egg was humanely sacrificed due to severe disease signs. B) Virus titers in lung homogenates of mice (4/group) infected with 10⁷ EID₅₀ of the WT702, QA23CkA10 PP, QA23 PP and QA23ML-3 Egg viruses as indicated. E627 and K627 correspond to the encoded amino acid position 627 in PB2.