Figure 1

Attenuation of H7N9/AAca in mice.

Groups of eight mice were intranasally inoculated with 10⁶ EID₅₀ of H7N9/AAca or rAH/1. Three mice in each group were killed on day 3 p.i. and nasal turbinates, lungs, spleens, kidneys and brains were collected for virus titration in eggs (A). The remaining five mice were observed for weight changes over 14 days (B). The dashed line indicates the limit of detection. a, P < 0.001 compared with the corresponding value for rAH/1-inoculated animals.