Examining how antibiotics affect immune responses to vaccines
A Human Experimental Medicine Study to Assess Whether the Gut Microbiota Regulates Specific and Non-specific Immune Responses to Vaccination
This study tests how taking antibiotics affects the immune response to vaccines in healthy adults aged 18-35.
Quick facts
| Phase | Phase 4 |
|---|---|
| Study type | Interventional |
| Enrollment | 348 (estimated) |
| Ages | 18 Years to 35 Years |
| Sex | All |
| Sponsor | South Australian Health and Medical Research Institute Academic / other |
| Locations | 1 site (Adelaide, South Australia) |
| Trial ID | NCT06148025 on ClinicalTrials.gov |
What this trial studies
This clinical trial investigates the impact of gut microbiota depletion through antibiotics on immune responses to the BCG vaccine in healthy adults aged 18-35. It consists of two sub-studies: the first assesses the immune response to a BCG challenge after antibiotic treatment, while the second evaluates the response to a Yellow Fever vaccine. Participants are randomized to receive either antibiotics or a placebo before vaccination, followed by a re-challenge with the BCG vaccine or Yellow Fever vaccine. The study aims to determine if antibiotic-induced changes in gut bacteria affect vaccine efficacy.
Who should consider this trial
Good fit: Ideal candidates are healthy adults aged 18-35 who are BCG and Yellow Fever vaccine naïve and willing to participate in the study procedures.
Not a fit: Patients with previous vaccinations for BCG or Yellow Fever, or those with certain health conditions that contraindicate vaccination, may not benefit from this study.
Why it matters
Potential benefit: If successful, this study could enhance our understanding of how gut health influences vaccine responses, potentially leading to improved vaccination strategies.
How similar studies have performed: While the specific approach of this study is novel, previous research has indicated that gut microbiota can influence immune responses, suggesting potential for success.
Eligibility criteria
Show full inclusion / exclusion criteria
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 taking corticosteroids or other immunosuppressive agents and haematopoietic stem cell transplant recipients * People who have had a haematopoietic stem cell transplant * Individuals with history of severe allergic reactions to egg or chicken proteins * Pregnant or breastfeeding or planning to become pregnant * History of renal disease/insufficiency * Tattoo obscuring BCG vaccination site(s) * Any history of severe allergic reaction or anaphylaxis to vaccination or antibiotics * People with chronic serious underlying illness * Have received any prescribed oral or intravenous antibiotic in the 28 days prior to study visits 1 and 4 (including isoniazid, rifampicin, streptomycin and ethambutol as these particular antibiotics have activity against M. bovis)
Where this trial is running
Adelaide, South Australia
- South Australian Health and Medical Research Institute — Adelaide, South Australia, Australia (Recruiting)
Study contacts
- Principal investigator: Simone Barry — Royal Adelaide Hospital
- Study coordinator: David Lynn
- Email: david.lynn@sahmri.com
- Phone: +61 8 8128 4053
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.