Using Inflammation as a Framework to Assess Hepatitis B Vaccine Immunity 2259206

Abstract Introduction Infection with hepatitis B virus (HBV) remains a major global health concern despite being vaccine-preventable for nearly four decades. Although vaccination has significantly reduced disease burden, a subset of individuals fails to develop adequate protection and are classified as non-responders. Methods A longitudinal study evaluated hepatitis B vaccine responses in individuals with or without prior vaccination. Participants received either a 3-dose alum-adjuvanted or 2-dose CpG-adjuvanted vaccine, with a subset receiving a booster. ELISA analyzed blood samples collected on days 1, 8, and 30 to quantify anti-HBs titers, classified as high (≥50 mIU/mL), moderate (10—50 mIU/mL), or low (≤10 mIU/mL). Antibody avidity was measured using a modified ELISA with a chaotropic agent to assess binding strength. Results Age significantly affected vaccine responses. In the booster group, participants under 50 had higher baseline titers, while in the de novo group, younger individuals showed stronger early responses though final titers were similar across ages. Among hypertensive participants, older adults showed slower but steady antibody increases, surpassing younger participants by week 4. Avidity remained stable across both vaccine groups, indicating that prior vaccination increased antibody quantity but not binding strength, which plateaued early. Conclusion Immune recall among previously vaccinated individuals was variable. Although boosters produced a faster antibody rise, a higher proportion of non-responders suggests that prior vaccination does not always ensure lasting protection. Hypertension also shaped vaccine response: while hypertensive individuals achieved early seroconversion, their antibody levels plateaued at lower magnitudes, suggesting impaired immune sustainment possibly linked to vascular inflammation or endothelial dysfunction.Overall, these findings highlight the need for personalized vaccination strategies for individuals with hypertension or advanced age. Funding Source Research reported in this abstract was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number AI158617. Additionally, supported by Hevolution/AFAR New Investigator Award Topic Categories Vaccines and Immunotherapy (VAC)