Antibody Repertoire of Human Polyclonal Antibodies Against Ebola Virus Glycoprotein Generated After Deoxyribonucleic Acid and Protein Vaccination of Transchromosomal Bovines.

Several Ebola vaccines and therapeutics are under clinical development. However, limited knowledge exists on the quality of antibody response generated by different Ebola vaccines. In this study, antibody repertoire induced by vaccination of transchromosomal bovine (TcB) with Ebola virus (EBOV) glycoprotein ([GP]; recombinant GP [rGP]) encoded by either deoxyribonucleic acid (DNA) or nanoparticle-based vaccine platform was analyzed using EBOV genome fragment phage display library and surface plasmon resonance (SPR)-based real-time kinetics assay to measure antibody affinity maturation to both native and partially denatured Ebola GP as well as GP containing the receptor binding domain but lacking the mucin-like domain. Immunoglobulin (IgG) obtained from rGP nanoparticle-vaccinated TcB demonstrated ~4-fold higher binding affinity compared with DNA-vaccinated TcB-induced IgG against the native rGP's. The rGP nanoparticle vaccine generated a more robust and diverse antibody immune response to the native EBOV-GP compared with the DNA vaccine, which may explain the protective efficacy observed for these antibody preparations.