Fig. 4: AdC68-G and DNA vaccines protected Syrian golden hamsters from lethal NiV Malaysia challenge.

Survival (a–c) and weight change (d–f) of Syrian hamsters challenged with the NiV Malaysia strain. Viral loads in the hamster lungs, brain, and spleen at 5 d.p.i. quantified by quantitative PCR with reverse transcription (qRT–PCR) (g) and live virus titration (h). i Lung tissue sections were stained with hematoxylin and eosin (HE). Marked bronchointerstitial pneumonia with inflammatory cell infiltration or necrosis (black arrows), hemorrhage (yellow arrows), vasculitis (green arrows), and fibrous exudation (blue arrows) in the lung tissue of control animals. No pathology was observed in vaccinated animals. j Lung tissue sections were stained with an antibody against the NiV N antigen, which was visible as red‒brown staining (IHC). No immunoreactivity was found in vaccinated animals, whereas multifocal immunoreactivity could be found in the lung tissue of control animals. k Spleen tissue sections were stained with hematoxylin and eosin (HE). Loss of normal splenic architecture, with lymphocyte necrosis (white circles) and decreased lymphocyte numbers in white pulp (white arrows); the asterisk indicates the central artery. l Spleen tissue sections were stained with an antibody against the NiV N antigen, and red‒brown color indicates immunolabeled mononuclear or multinucleated cells. Data are presented as the group mean ± SEM. Two-tailed unpaired Student’s t tests were conducted to compare differences between two experimental groups. **p < 0.01, ***p < 0.001, ****p < 0.0001. Error bars indicate 95% confidence intervals. L.O.D. represents the limit of detection. Bar scale, 50 µm.