SAFETY AND IMMUNOGENICITY OF INACTIVATED FOWL ADENOVIRUS SEROTYPE 8B ISOLATE FOLLOWING DIFFERENT INACTIVATION TIME INTERVALS IN BROILER CHICKENS

Document Type : Original Articles

Authors

1 Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

2 Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

3 Department of Veterinary Laboratory Diagnosis, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

4 Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

10.22092/ari.2024.364493.2985

Abstract

In recent years, much attention has been focused on the development of inactivated fowl aviadenovirus (FAdV) vaccines in the poultry industry against inclusion body hepatitis (IBH) outbreak. It was the objective of this study to determine the safety and immunogenicity of inactivated FAdV vaccine following different inactivation time intervals in commercial broiler chickens. FAdV isolate, UPM1137 was treated with binary ethyleneimine (BEI) at 20 hours (h), 24h, 28h, 32h and 36h. All treated isolates were furthered tested for safety test in specific pathogen free (SPF) chicken embryonated eggs (CEE) followed by safety and immunogenicity trial in SPF chickens. Based on the current findings, it was demonstrated that the isolate treated at 20h, 24h and 28h induce more than 80% mortality in SPF CEE, while, no mortality was recorded for isolate treated at 32h and 36h. In SPF chickens, neither clinical signs, nor gross and histological lesions were recorded throughout the trial after inoculated with isolate treated at 32h and 36h. The isolate treated at 32h and 36h are completely inactivated and safe in commercial broiler chicken. Based on ELISA findings, chickens vaccinated with inactivated FAdV at 32 hours (h) (group B) induce high antibody response compared to that inactivated FAdV at 36h (group A) at day 14 and 28pi. At day 28pi, mean antibody titer for booster groups in group A and B were significantly high (p < 0.05) compared to the control group. It showed that both FAdV vaccine using inactivated inoculum at 32h and 36h are safe and immunogenic in broiler chickens typically at day 28pi following booster vaccination. It was concluded that the optimal period of FAdV inactivation was 32 hours and highly suitable to be used for future vaccine formulation.

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