A novel chimpanzee adenovirus vector vaccine for protection against infectious bronchitis and Newcastle disease in chickens.

The development of effective poultry vaccines is crucial for maintaining flock health and productivity. In this study, we developed and evaluated a recombinant chimpanzee adenovirus vaccine (PAD-S1-HN) that simultaneously expresses the infectious bronchitis virus (IBV) spike subunit protein S1 and Newcastle disease virus (NDV) hemagglutinin-neuraminidase HN protein. The recombinant virus was successfully rescued in HEK293 cells, and transmission electron microscopy confirmed its typical adenoviral morphology. The expression of the IBV S1 and NDV HN proteins was validated by indirect immunofluorescence assay and western blotting. The vaccine demonstrated genetic stability over multiple passages and exhibited growth kinetics similar to those of the empty chimpanzee adenovirus vector. In animal trials, PAD-S1-HN effectively induced IBV- and NDV-specific antibodies, increased key cytokine levels, and stimulated mucosal immune responses, resulting in reduced viral loads, and alleviated clinical symptoms in vaccinated chickens. These findings indicate that the PAD-S1-HN vaccine provides strong immunogenicity and protective efficacy against IBV and NDV infections. Therefore, it presents a promising alternative to conventional vaccines, offering a novel approach for improving poultry disease management.