Immunological Tolerance After Frequent Rabies Booster Vaccinations

Not Applicable

• Conditions: Rabies
• Interventions: Biological: Blood drawn after rabies vaccine booster vaccination

• Registration Number: NCT03729102
• Lead Sponsor: Queen Saovabha Memorial Institute

Brief Summary

To study immunological tolerance effect after frequent rabies booster vaccination

Detailed Description

Previous studies had shown lower antibody titers among those who received frequent rabies booster vaccination, compared to ones who had got primary immunization. We study immunological cells i.e., regulatory T cell, regulatory B cell, T follicular helper cell, and cytokines in those who received frequent rabies booster vaccination.

Study Timeline

• Study First Submitted: 2018-10-30
• Study First Submitted QC: 2018-11-01
• Study First Posted: 2018-11-02
• Study Start: 2020-06-04
• Status Verified: 2022-04
• Last Update Submitted: 2022-04-28
• Last Update Posted: 2022-04-29
• Primary Completion: 2023-12
• Study Completion: 2023-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Healthy adults
• Previously received rabies vaccination

Exclusion Criteria

• Had immunocompromised conditions
• Received blood or blood product within 3 months
• Received anti-malarial drugs

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Study group	Blood drawn after rabies vaccine booster vaccination	Persons who had received primary immunization and later received booster vaccination for at least 3 times
Control group	Blood drawn after rabies vaccine booster vaccination	Persons who had received primary immunization

Primary Outcome Measures

Name	Time	Method
Rabies specific regulatory T cells	Change from baseline of numbers of Rabies specific regulatory T cells before (baseline) and one month after receipt of rabies booster vaccination were compared between 2 arms	Rabies specific regulatory T cells are measured by flow cytometry method
Rabies specific regulatory B cells	Change from baseline of numbers of Rabies specific regulatory B cells before (baseline) and one month after receipt of rabies booster vaccination were compared between 2 arms	Rabies specific regulatory B cells are measured by flow cytometry method
Rabies specific T follicular helper cells	Change from baseline of numbers of Rabies specific T follicular helper cells before (baseline) and one month after receipt of rabies booster vaccination were compared between 2 arms	Rabies specific T follicular helper cells are measured by flow cytometry method

Secondary Outcome Measures

Name	Time	Method
Rabies Neutralizing Antibody Titers (RNab)	before (baseline) and one month after receipt of rabies booster vaccination	Rabies Neutralizing Antibody Titers would be represented and compared by geometric mean titers (GMTs)

Trial Locations

Locations (1)

Queen Saovabha Memorial Institute; 🇹🇭 Pathum Wan, Bangkok, Thailand