Formulation of HBs antigen in Montanide ISA266 shows superiority to commercial HBsAg vaccine in the induction of humoral immune responses

Aim: In the present study, a new formulation of HBsAg vaccine was developed and compared with a commercial peer. Background: Vaccination of hepatitis B infection has been an unavoidable affair since the 1980s, though it has numerous limitations such as inefficacy in the induction of cellular immune responses. To address these limitations, research on novel formulations is necessary to develop a superior formulation with the potency of induction of both cellular and humoral immune responses. Methods: HBsAg was formulated in oil-in-water adjuvant Montanide ISA-266 (5 μg/dose) using homogenizer. Balb/C mice were then immunized three times at days 0, 14, and 28 with HBsAg/Montanide ISA-266 or HBsAg/alum with proper control groups. Two weeks after the last immunization, immunological parameters including IL-2, IL-4, TNF-α, IFN-γ, total IgG and IgG1/IgG2a isotypes were assessed by ELISA. Results: The results demonstrated that the formulation of HBsAg with Montanide ISA-266 enhanced humoral immune responses versus the commercial vaccine and control groups. No significant difference in terms of Th1 pattern was found between HBsAg/Montanide ISA-266 and the commercial vaccine. Conclusion: Formulation of HBsAg with an oil-based adjuvant may be useful for the induction of a more potent humoral immune response compared to the commercially available HBV vaccine.