Most
vaccines require adjuvants for
antigen stabilization and immune potentiation.
Aluminum-based adjuvants are the most widely used adjuvants for human
vaccines. Previous reports demonstrated the preservation of
antigen conformation and other
antigen characteristics after recovery from adjuvanted
Hepatitis B and
human papillomavirus vaccines. In this study, we used a combination of various physiochemical and immunochemical methods to analyze
hepatitis E vaccine antigen quality attributes after recovery from adjuvants. All biochemical and biophysical methods showed similar characteristics of the p239
protein after recovery from adjuvanted
vaccine formulation compared to the
antigen in
solution which never experienced adsorption/desorption process. Most importantly, we demonstrated full preservation of key
antigen epitopes post-recovery from adjuvanted
vaccine using a panel of murine
monoclonal antibodies as exquisite probes. Antigenicity of p239 was probed with a panel of 9 mAbs using competition/blocking ELISA, surface plasmon resonance and sandwich ELISA methods. These multifaceted analyses demonstrated the preservation of
antigen key
epitopes and comparable
protein thermal stability when adsorbed on adjuvants or of the recovered
antigen post-dissolution treatment. A better understanding of the
antigen conformation in adjuvanted
vaccine will enhanced our knowledge of
antigen-adjuvant interactions and facilitate an improved process control and development of stable
vaccine formulation.