Generation and evaluation of anti-SARS-CoV-2 RBD-S chicken IgY antibodies for passive immunisation research

Coronaviruses (CoVs) cause severe respiratory diseases and continue to pose a significant worldwide health threat. Antibodies that specifically target the structural proteins of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) are crucial for immunological research, development of diagnostic assays, and evaluation of immune responses. Avian egg yolk immunoglobulin Y (IgY) represents a novel approach that has attracted considerable interest due to its strong immunological response, scalability, and excellent safety profile. The study involved generating SARS-CoV-2 receptor-binding domain (RBD)-specific spike (S) IgY antibodies by immunising laying hens with a synthetic RBD epitope. IgY antibodies were extracted from egg yolks using optimised purification methods and subsequently characterised for yield, purity, and antigen specificity. The purified IgY preparations were evaluated and verified for specificity and binding affinity to the target antigen using indirect enzyme-linked immunosorbent assay (ELISA), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), conventional Western blotting, and automated Jess Western blot analysis. The produced antibodies exhibited targeted recognition of the antigen and were effectively purified with commendable yield and purity, highlighting their potential as a cost-effective, scalable, and dependable source of primary antibodies for immunological research and diagnostic applications. Additional research, including virus-neutralisation and in vivo efficacy assessments, is needed to explore their potential for passive immunisation and various biomedical applications.