Objective: This study evaluated a novel trivalent inactivated FAdV vaccine containing antigens from FAdV-4, 8b, and 11. Methods: An SD1356-like FAdV-8b strain, representing newly emerging variants in Asia and the Middle East, was included as an immunogen. Prior to vaccination-challenge trials, pathogenicity of FAdV-4, 8b, and 11 was assessed in chickens via oral, intramuscular, and intravenous routes. These models were used to determine the minimum protective dose.Cross-neutralization assays were performed using sera from monovalent vaccinations for each serotype. Duration of immunity was evaluated in specific pathogen-free chickens following a single vaccine dose. Results: Intravenous challenge produced the highest mortality across all serotypes, including the relatively low-pathogenic FAdV-11. A vaccine dose of 107.0TCID50 /bird induced strong neutralizing antibody responses and provided complete protection against virulent strains.Sera showed no cross-neutralization between heterologous serotypes, emphasizing the necessity of multivalent formulations. Protective antibody titers were maintained up to 78 weeks of age. Conclusions and Relevance: The trivalent vaccine provides effective protection against predominant FAdV-4, 8b, and 11 strains. These findings support the use of multivalent vaccines to achieve broad and sustained immunity against emerging FAdV infections in poultry.

The rapid detection and differentiation of major respiratory viruses, such as avian influenza, infectious bronchitis virus, Newcastle disease virus, infectious laryngotracheitis virus, and avian metapneumoviruses within an infected poultry flock, are crucial for timely control measures. Effective disease management mandates identifying the etiologic agent and differentiating between similar pathogens in the early stages of infection. The traditional methods of virus detection include virus isolation, virus neutralization, and hemagglutination inhibition assays. Molecular-based methods, such as quantitative real-time polymerase chain reaction (PCR), have also become a standard. Future diagnostic concepts focus on advances in point-of-care testing that can be applied directly on-site in poultry plants, such as biosensing and lateral flow tests, which are becoming prominent in avian diagnostics. Portable PCR assays, such as loop-mediated isothermal amplification, are also becoming popular. In addition, artificial intelligence, particularly those using deep-learning techniques, is increasingly being integrated into early disease detection. This comprehensive review examines the history of diagnostic methodologies that have supported these efforts for decades and discusses future concepts and trends in the field.

Newcastle disease (ND), infectious laryngotracheitis (ILT) and avian metapneumovirus (aMPV) can be similar making it critical to quickly differentiate them. Herein, we adapted pre-existing molecular-based diagnostic assays for NDV and ILTV, and developed new assays for aMPV A and B, for use under synchronized thermocycling conditions. All assays performed equivalently with linearity over a 5 log 10 dynamic range, a reproducible (R 2 > 0.99) limit of detection of ≥ 10 target copies, and amplification efficiencies between 86.8%– 98.2%. Using biological specimens for NDV and ILTV showed 100% specificity. Identical amplification conditions will simplify procedures for detection in diagnostic laboratories.