Systemic Inflammation and the Persistence of Vaccine-Induced Hepatitis B Immunity in Healthcare Workers.

BACKGROUND The long-term persistence of hepatitis B surface antigen (anti-HBs) levels varies among individuals, and the role of systemic inflammation remains unclear. This study evaluated the relationship between anti-HBs antibody levels and systemic inflammatory markers in healthcare workers. MATERIAL AND METHODS This longitudinal observational study with a retrospective component included 583 healthcare workers who underwent routine occupational health screening between 2023 and 2025. Anti-HBs levels at 2 time points were analyzed together with C-reactive protein (CRP) level, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, and systemic inflammation response index. Nonparametric and correlation analyses were performed. RESULTS Anti-HBs levels decreased significantly between baseline and follow-up (Hodges-Lehmann estimate: -23.00 mIU/mL, 95% CI: -27.60 to -18.93; P<0.001). No significant associations were observed between antibody levels and sex, smoking status, or the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, and systemic inflammation response index. In contrast, CRP positivity was associated with lower anti-HBs levels at the second measurement; however, no association was observed between CRP and longitudinal change in anti-HBs levels. Higher anti-HBs levels were observed among physicians and healthcare workers in the very high occupational biological-risk group, whereas age showed a weak negative correlation with antibody levels. CONCLUSIONS CRP showed a weak cross-sectional association with lower anti-HBs levels at the second measurement, whereas no association was observed between CRP or the other inflammatory indices and longitudinal change in anti-HBs levels. Therefore, the present findings do not establish systemic inflammation as a determinant of longitudinal antibody persistence. Further longitudinal studies are required to determine whether systemic inflammatory markers have clinical utility in post-vaccination immunity monitoring.