Comparative Immunogenicity of a High-Dose Hepatitis B Virus (HBV) Vaccine with Rapid Immunization vs. Standard Schedule in HBV Vaccine-Naïve Adults Aged 25-55 in China

The 20 mu g (0-1-6 month) hepatitis B virus (HBV) vaccination is widely recommended for HBV vaccine-na & iuml;ve immune adults in China. However, suboptimal protective responses may occur due to dose-series incompletion. We aim to investigate the immunogenicity of a 60 mu g HB vaccine with a 0-2 month series among HBV vaccine-na & iuml;ve immune adults aged 25-55 to assess potential alternative approaches for HB immunization. A two-center randomized controlled trial was carried out. Participants were randomly allocated to either the 20 mu g (0-1-6 month) or the 60 mu g (0-2 month) regimen. Blood samples were collected eight weeks after the final injection to measure the antibodies. A total of 583 adults (289 in the 20 mu g regimen and 294 in the 60 mu g regimen) were included. The seroprotection rates (SPRs) were 97.23% and 93.54% in the 20 mu g and 60 mu g regimens, respectively (p = 0.0261), and the geometric mean concentrations were 600.76 mIU/mL and 265.68 mIU/mL, respectively (p < 0.0001). The immunogenicity of the 60 mu g regimen decreased significantly with age, particularly in adults aged 40 and older. The 60 mu g regimen may be beneficial for adults under 40, especially those with poor compliance or in urgent need of immunization.