MedTrace Logo

Study of the Cellular Response Induced After Vaccination Against the Hepatitis B Virus

NCT06876467 · Status: RECRUITING · Type: OBSERVATIONAL · Enrollment: 115

Last updated 2026-04-23

No results posted yet for this study

Summary

296 million people worldwide are infected with the hepatitis B virus (HBV), despite the existence of an effective prophylactic vaccine. Current treatments (nucleoside analogues and pegylated interferon-α) do not prevent chronic hepatitis B (CHB) patients from developing liver fibrosis or hepatocellular carcinoma.

Vaccination is the best way to prevent HBV infection. The first generation of plasma-based vaccines, introduced in the 1980s, has now been superseded by protein vaccines, which are the only ones authorized in France. They are safe and effective. After an initial series of three out of four doses, protective levels of antibodies to the HBV surface antigen (anti-HBsAg; ≥10 IU/mL) are achieved in over 95% of infants, children and young adults.

HBV antigen (Ag)-specific CD4+ and CD8+ T lymphocytes play a major role in the control of HBV infection, contributing to viral clearance and the pathophysiology of acute hepatitis B. However, during HBC, these HBV-specific T cells develop a dysfunctional phenotype and become 'exhausted'. T lymphocytes directed against surface protein antigens (HBsAg) are the most affected by depletion mechanisms - these disappear completely in chronically infected patients, suggesting an important role for these T lymphocytes in infection control. Interestingly, recent studies of rare patients undergoing functional recovery from chronic infection following antiviral treatment have shown a re-emergence of T lymphocytes directed against HBsAg, confirming the importance of these cells in controlling viral replication. Although the protection induced by hepatitis B vaccination has mainly been attributed to the humoral response, a few studies have documented the presence of HBsAg-specific T lymphocytes. These could contribute to the maintenance of a long-term post-vaccination humoral response. The aim of this study is therefore to determine the frequency of healthy individuals receiving HBV vaccination who have a detectable HBsAg-specific T-cell response post-vaccination. We will also study the potential correlation between the frequency of HBsAg-specific T lymphocytes and the level of serum anti-HBsAg antibodies, and we will finely characterize the functional phenotype of these cells using cutting-edge methods and technologies (spectral cytometry, sequencing of mRNA and TCRs). These data will contribute to a better understanding of the biological mechanisms associated with HBV vaccine-induced protection.

Conditions

  • Hepatitis B Vaccination
  • Immune Response
  • T Cells

Interventions

OTHER

Evaluation of cellular response

detection of HBsAg-specific T lymphocytes by spectral cytometry

Sponsors & Collaborators

  • Assistance Publique - Hôpitaux de Paris

    lead OTHER

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2025-08-11
Primary Completion
2028-12-11
Completion
2028-12-11

Countries

  • France

Study Locations

More Related Trials

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT06876467 on ClinicalTrials.gov