Importance of Vaccine Adjuvants: A Comparative Study of Antibody Acquisition Rates and Levels Before and After Adjuvant Change in the Hepatitis B Vaccine

Objective Hepatitis B (HB) is a significant global public health concern, and the World Health Organization has emphasized the importance of HB vaccination programs. Currently, there are only two commercially available HB vaccines in Japan: HEPTAVAX^®-II and Bimmgen^®. Antibody acquisition and maintenance are crucial for HB vaccinations. Methods In this study, we used a modified version of HEPTAVAX^®-II (mpHBV) with a doubled aluminum-to-phosphate ratio of the adjuvant aluminum hydroxyphosphate sulfate to assess the vaccine's antibody acquisition rate and antibody levels six months post-vaccination compared to conventional HEPTAVAX^®-II. Patients A total of 741 second-year students from Showa University School of Medicine, Dentistry, and Pharmacy were included in this study. Results The antibody acquisition rate (≥10 mIU/mL) for mpHBV was 84% (321/382) with a confidence interval (CI) of 0.803-0.877, while that for HEPTAVAX^®-II was 68.5% (246/359) with a CI of 0.637-0.734. The geometric mean titer (mIU/mL) for mpHBV was 55.0 mIU/mL with a CI of 46.9-64.5, while that for HEPTAVAX^®-II was 24.1 mIU/mL CI 20.7-28.2. Both the antibody acquisition rate and geometric mean titer were significantly higher for mpHBV than for HEPTAVAX^®II. Conclusion The adjuvant-modified HB vaccine was effective in maintaining vaccine antibody acquisition rates and levels. Adjuvants are important for antibody acquisition and maintenance during vaccine production.