FA4-EGFP provided efficient protection against lethal challenge. The SPF chickens inoculated with FA4-EGFP were challenged at 21 dpi with the lethal dose of FAdV-4. The clinical symptoms and mortality of the challenged chickens were monitored daily, and the liver, spleen, kidney, and cloacal swabs were collected for viral titration at the indicated time points. A Percent of survival for the challenged chickens. B The representative gross lesion in the heart and liver from the challenged control chickens (a) and the challenged chickens previously inoculated with FA4-EGFP (b). Viral shedding in cloacal swabs from the challenged chickens. C Viral loads in the liver (D), spleen (E), and kidney (F) tissues from the challenged chickens.