Characterization of antigen adjuvant interactions in polyacrylate adjuvanted vaccines

SPA09 is a polyacrylate-based clinical stage vaccine adjuvant that was found to exert a strong adjuvant effect on various vaccine antigens including recombinant cytomegalovirus glycoprotein B (CMV-gB). For the characterization of antigen-adjuvant interactions, which is a regulatory requirement and an important piece of information for the understanding of adjuvant mechanism of action, we developed a set of orthogonal techniques, comprising thermal analyses, biolayer interferometry and agarose gel migration assays. Here we apply these techniques to study the interaction between SPA09 and two recombinant proteins from the Sanofi new vaccine portfolio, CMV-gB and the Staphylococcus aureus chaperone protein, PrsA, that we used as model antigens. We believe that the techniques developed for this work could be useful to study the interactions between adjuvants and vaccine antigens in general and could be broadly applicable for the characterization of adjuvanted vaccine products.