Immune Determinants in the Acquisition and Maintenance of Antibody to Hepatitis B Surface Antigen in Adults After First-Time Hepatitis B Vaccination.

Global implementation of a birth-dose hepatitis B (HB) vaccine has significantly reduced the prevalence of hepatitis B virus (HBV) carriers. Durable and sufficient titers of antibodies to hepatitis B surface antigen (anti-HBs) are desirable for vaccinees to gain resistance to HBV exposure. However, the existence of primary nonresponders and vaccinees who lost anti-HBs over time remains a challenge for the strategy of HBV elimination. We thus aim to clarify the mechanisms of acquisition and maintenance of vaccine-induced anti-HBs in healthy adults. We retrospectively analyzed the vaccination records of 3,755 first-time HB-vaccinated students and also traced the acquired antibody transition of 392 first-time vaccinees for 10 consecutive years. To understand the cellular and humoral immune response, we prospectively examined peripheral blood from 47 healthy first-time HB-vaccinated students, 62 booster-vaccinated health care workers, and 20 individuals who maintained their anti-HBs. In responders, a significant increase of follicular helper T (Tfh) cells, activated plasmablasts, and plasma cells was observed in first-time-vaccinated but not booster-vaccinated persons. We also discovered memory B cells and antibody-secreting cells were more abundant in individuals who maintained anti-HBs. According to vaccination records, higher anti-HBs antibody titer acquisition was related to the longer term maintenance of anti-HBs, the level of which was positively correlated with prevaccination levels of serum interferon-γ and related chemokines. The second series of vaccination as a booster provided significantly higher anti-HBs antibody titers compared to the initial series. Conclusion: Coordinated activation of Tfh and B-cell lineages after HB vaccination is involved in the acquisition and maintenance of anti-HBs. Our findings support the rationale of preconditioning the immune status of recipients to ensure durable vaccine responses.