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Antibiotics and Vaccine Immune Responses Study

ConditionVaccine Response Impaired
Trial statusRecruiting
Trial phasePhase 4
Trial typeInterventional
Biological sexAll
Age18-35
SponsorSouth Australian Health and Medical Research Institute

About this trial

The goal of this clinical trial is to examine immune responses to the BCG vaccine in healthy adults who have, or who have not, taken antibiotics to deplete their gut bacteria prior to vaccination.

The main question it aims to answer is: does depletion of the gut microbiota lead to impaired BCG-induced protection against specific and non-specific to challenges to the immune system?

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

18-35 years old

Provided a signed and dated informed consent form

BCG naïve (Arm 1) and BCG and YF vaccine naïve (Arm 2)

Willing to take short antibiotic course

Disqualifiers

Previous BCG vaccination

Previous YF vaccination or YFV infection (only applies to participants included in the Yellow Fever Vaccine challenge sub-study)

Evidence of TB infection (assessed through a questionnaire - IGRA to confirm if needed)

malignancies involving bone marrow or lymphoid systems, primary or secondary immunodeficiencies, HIV infection

Trial design

Design model

Parallel

Treatments tested in this trial

  • BCG vaccine

    Biological/Vaccine

    0.1ml injected intradermally over the distal insertion of the deltoid muscle onto the humerus

  • Yellow Fever vaccine

    Biological/Vaccine

    0.5ml injected subcutaneously

  • Vancomycin Oral Capsule

    Drug

    500mg every 6 hours for 3 days

  • Neomycin Oral Product

    Drug

    1000mg every 6 hours for 3 days

  • Metoclopramide (Maxolon)

    Drug

    10mg every 8 hours

  • Loperamide HCl

    Drug

    2mg tablets/capsules: 2 tablets/capsules initially, followed by 1 tablet after each loose motion, to a maximum of 8 tablets/capsules per day

Treatment groups

348 Participants
are divided into 8 treatment groups

8

Treatment groups

See each treatment group below.

Group A: Substudy 1 - BCG vaccine, antibiotics and 2nd BCG vaccineExperimental treatment 5 interventions
Group B: Substudy 1 - BCG vaccine, no antibiotics and 2nd BCG vaccineExperimental treatment 1 intervention
Group C: Substudy 1 - BCG vaccine, antibiotics and placebo vaccineExperimental treatment 5 interventions
Group D: Substudy 1 - BCG vaccine, no antibiotics and placebo vaccineExperimental treatment 1 intervention
Group E: Substudy 2 - Yellow Fever vaccine, antibiotics and BCG vaccineExperimental treatment 6 interventions
Group F: Substudy 2 - Yellow Fever vaccine, no antibiotics and BCG vaccineExperimental treatment 2 interventions
Group G: Substudy 2 - Yellow Fever vaccine, antibiotics and placebo vaccineExperimental treatment 5 interventions
Group H: Substudy 2 - Yellow Fever vaccine, no antibiotics and placebo vaccineExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Sub-study 1 BCG re-challenge

Mycobacterial load (Colony Forming Units (CFU)/mg tissue) in the skin biopsy site in BCG-vaccinated participants not exposed to antibiotics (BCG-No ABX) compared to BCG-vaccinated participants that were exposed to antibiotics (BCG-ABX)

Time frame
2 weeks post BCG challenge
2

Sub-study 2 Yellow Fever vaccine

Peak Yellow Fever viremia (viral copies/ml plasma) at day 3-7 post YFV vaccination in BCG-vaccinated participants not exposed to antibiotics (BCG-No ABX) compared to BCG-vaccinated participants that were exposed to antibiotics (BCG-ABX)

Time frame
3, 5, 7 days post YFV challenge

Secondary outcomes

1

Sub-study 1 - Bacterial load

Bacterial load (16S rRNA gene copies/g stool) in ABX participants compared to No-ABX participants

Time frame
Baseline (1-2 weeks before BCG/placebo vaccination), Day of vaccination and Day of BCG challenge
2

Sub-study 2 - Bacterial load

Bacterial load (16S rRNA gene copies/g stool) in ABX participants compared to No-ABX participants

Time frame
Baseline (1-2 weeks before BCG/placebo vaccination), Day of vaccination and Day of YFV challenge
3

Sub-study 1 - Microbiota diversity

Microbiota diversity (Shannon diversity index) in ABX participants compared to No-ABX participants

Time frame
Baseline (1-2 weeks before BCG/placebo vaccination), Day of vaccination and Day of BCG challenge
4

Sub-study 2 - Microbiota diversity

Microbiota diversity (Shannon diversity index) in ABX participants compared to No-ABX participants

Time frame
Baseline (1-2 weeks before BCG/placebo vaccination), Day of vaccination and Day of YFV challenge

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

South Australian Health and Medical Research Institute

Lead sponsor

Royal Adelaide Hospital

Collaborator

Flinders University

Collaborator

University of Sydney

Collaborator

Telethon Kids Institute

Collaborator

Centenary Institute

Collaborator

Source ClinicalTrials.gov
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