Enhanced protective immunity of inactivated AI H9N2 vaccine by co-administration ofS. entericaserovar Typhimurium expressing chIFN-a and chIL-18. (A) Mortality of AIV H9N2-challenged chickens. Groups of chickens were administered S. enterica serovar Typhimurium expressing chIFN-α and chIL-18 (109 and 1011 cfu/chicken) and vaccinated with inactivated AIV H9N2 three days later. Vaccination was performed twice at 7-day intervals. Seven days after booster vaccination, chickens were intra-tracheally infected with AIV H9N2 (1010.83 EID50/bird). Graphs show the proportion of surviving chickens on days p.i. (B) Clinical severity of AIV H9N2-challenged chickens. Chickens immunized with inactivated AIV H9N2 vaccine were challenged with AIV H9N2 virus and clinical severity scored daily. (C and D) Feed and water intake of AIV H9N2-challenged chickens recorded daily after AIV H9N2 challenge of inactivated AIV H9N2-vaccinated chickens. Data show the average feed (C) and water (D) intake obtained from eight chickens per group.
Rahman et al. BMC Veterinary Research 2012 8:105 doi:10.1186/1746-6148-8-105