NCT06876467: HBVax

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

Not yet recruiting Last updated 14 March 2025

What this trial tests

trial testing Evaluation of cellular response in Hepatitis B Vaccination in 115 participants. Not yet recruiting.

Timeline

1 April 2025

Primary endpoint
1 July 2028

1 July 2028

Quick facts

Lead sponsor	Assistance Publique - Hôpitaux de Paris
Status	Not yet recruiting
Study type	OBSERVATIONAL
Enrollment	115
Start date	1 April 2025
Primary completion	1 July 2028
Estimated completion	1 July 2028

Drugs / interventions tested

• Evaluation of cellular response

Conditions studied

• Hepatitis B Vaccination — all drugs for Hepatitis B Vaccination →
• Immune Response — all drugs for Immune Response →
• T Cells — all drugs for T Cells →

Sponsor

Assistance Publique - Hôpitaux de Paris — full company profile →

Who can join

18 and older, any sex, with Hepatitis B Vaccination or Immune Response. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

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 The first generation of plasma-based vaccines, introduced in the 1980s, has now been superseded by protein vaccines, which are the only ones authorized in France.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.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.