Protective Efficacy of rH120-Δ5ab-gD-T/B against ILTV. (A) Humoral immune response induced by rH120-Δ5ab-gD-T/B. Serum samples were collected from the rH120-Δ5ab-gD-T/B immunized group, rH120 immunized group, and control group at 7, 14, 21, and 28 dpv. ILTV antibody titers were measured by ELISA. The data shown are measurements for each group of ten chickens. (B) Shedding of virulent ILTV in tracheal swabs was detected at 3 dpc and 7 dpc. Data presented are the means ± SD for ten chickens per group. (C) The viral genome load of virulent ILTV in tracheal tissues was detected at 3 dpc and 7 dpc. Data presented are the means ± SD for four chickens per group. The differences between groups are analyzed using ANOVA (***P < 0.001).