Adsorption of recombinant poxvirus L1-protein to aluminum hydroxide/CpG vaccine adjuvants enhances immune responses and protection of mice from vaccinia virus challenge

► Biophysical characterization of the orthopoxvirus L1 vaccine antigen is presented. ► L1-protein adsorbed to Alhydrogel generated better IgG responses than non-adsorbed. ► Addition of CpG to Alhydrogel significantly enhances the anti-L1 antibody responses. ► L1 adsorbed to Alhydrogel resulted in better protection from vaccinia challenge. ► Vaccine formulation design is key to maximize vaccine immunogenicity and protection.