RecruitingPhase 4

Antibiotics and Vaccine Immune Responses Study

Australia348 participantsStarted 2023-11-23

Plain-language summary

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?

Who can participate

Age range

18 Years – 35 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * 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 * Willing to undergo a punch biopsy (Arm 1) * Willing to have up to 7 blood samples and 3 stool samples collected over 5-7 months * Not pregnant or intending to get pregnant for the duration of the study (a pregnancy test will be offered to females) Exclusion Criteria: * Previous BCG or YF vaccination * Previous YF infection * Evidence of latent TB infection (LTBI) (assessed through a questionnaire) (IGRA to confirm if needed) * People with contraindications for BCG vaccination: * malignancies involving bone marrow or lymphoid systems, primary or secondary immunodeficiencies, HIV infection * moderate/severe skin disease including eczema, dermatitis or psoriasis * requiring immunosuppressive drugs or other immune modifying drugs e.g. corticosteroids, non-biological immunosuppressants, biological agents (such as monoclonal antibodies against tumour necrosis factor (TNF)-alpha) * People with contraindications to YF vaccination: * History of thymus disease, including myasthenia gravis, thymoma, thymectomy, DiGeorge syndrome, thymic damage from chemoradiotherapy or graft-versus-host disease * YF vaccination is contraindicated in immunocompromised individuals, including individuals who have HIV infection, primary immunodeficiencies (including inherited IFNAR1 deficiency), or are ta…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Sub-study 1 BCG re-challenge

Timeframe: 5 years

Sub-study 2 Yellow Fever vaccine

Timeframe: 5 years

Trial details

NCT IDNCT06148025

SponsorSouth Australian Health and Medical Research Institute

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2027-10-01

Contact for this trial

David Lynn

+61 8 8128 4053 david.lynn@sahmri.com

View on ClinicalTrials.gov More Vaccine Response Impaired trials