Fig 7. Lethal challenge experiments.

Mice previously vaccinated were challenged intranasally with a lethal dose of 5x10⁴ PFU of influenza A/PR/8/34 virus. A) Weight change and B) Clinical score over the course of the disease. Mice were weighted and followed daily for two weeks. In graphs A and B are presented the mean values of each group with standard error. C) Survival curves of mice immunized with rVHSV-HA and rIHNV-HA and challenged with influenza. D) Disease severity. Each box represents one mouse and the severity of its disease when clinical signs were detected for more than 24h. Black indicates severe (maximum clinical score from 5 to 7), dark gray: moderate (3–4), light gray: mild (1–2) and white indicates that the mouse did not show any clinical sign for more than 24h.