Proper conformational arrangement of the E2 molecules of bovine viral diarrhoea-mucosal disease virus (BVD-MDV) is crucial to obtain an effective recombinant vaccine candidate against the disease. In this study, we characterised a new molecule composed of two distinct sequences of the E2 glycoprotein of BVD-MDV and the Fc fragment of human immunoglobulin (BVDE2Fc). The chimaeric protein was expressed in mammalian cell lines of different species by adenoviral transduction and purified by immobilised metal-affinity chromatography. The N-glycans were profiled by HPLC, and the BVDE2Fc immunogenicity was assessed in male mice. The antigen-antibody reactions were evaluated by ELISA. The MDBK cell line was selected from among five for the final production of BVDE2Fc. After purification to over 90%, the N-glycan profile showed neutral and complex oligosaccharides. The mouse immunisation induced a strong humoral response, which produced antibodies able to attach to conformational epitopes on E2 molecules, while the Fc fragment barely contributed to the immune response. Additionally, BVDE2Fc attached to antibodies from bovine sera positive to distinct BVD-MDV subtypes, whereas the loss of BVDE2Fc structure during the deglycosylation process considerably diminished those interactions. These results demonstrate that the structure of E2 molecules arranged in tandem and attached to an Fc fragment could represent a viable design for future vaccine candidates against BVD-MD.

Recently, Fowl Adenovirus (FAdV) cases have been reported in many countries worldwide. FAdV is a contagious agent associated with inclusion body hepatitis (IBH) and hydropericardium syndrome (HPS) in chickens. It belongs to the Aviadenovirus genus of the family Adenoviridae. The virus is classified into five species (A to E) and further divided into 12 serotypes. Depending on the serotypes, they have diverse characteristics of virus that can either be pathogenic or nonpathogenic strain. From the viewpoint of epidemiological as well as vaccine development, it is very important to detect FAdV strains. Previous studies have been conducted on molecular research, but the continuity of this study in Malaysia has been limited. This study aims to identify the serotype classification of five Malaysian FAdV isolates obtained from field outbreaks during 2017-2019. In this study, polymerase chain reactions (PCR) were conducted based on Hexon gene. Results from the nucleotide sequence analysis discovered that the five isolates showed high similarity with FAdV-8b strains. High bootstrap values in phylogenetic analysis supported the clustering of the Malaysian FAdVs isolates into FAdVs species E. Consequently, the result of this study contributed important information on the epidemiology and culminated in the importance of control strategies against FAdV infection in Malaysia.