An interventional study of BCG Danish in Tuberculosis, sponsored by University of Oxford. Active, not recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-24.
Sponsored by University of Oxford · Not applicable, Interventional, and Other
The purpose of this study is to:
It will involve 36 previously BCG-vaccinated participants. Bronchoscopies will be performed 14 days post-challenge to measure BCG recovered from bronchial samples. Blood tests will be taken to look at potential immunological markers of immunity.
Worldwide Tuberculosis (TB) remains the leading cause of death from an infectious disease. Key research priorities include the development of effective vaccine strategies.
Currently, the only licensed vaccine against TB is BCG (Bacille Calmette-Guérin) injected under the skin (intradermal). This works well as a single dose vaccination against TB in childhood but is often ineffective in adults. Previous studies have investigated the benefit of booster doses of intradermal BCG; although these have not shown a clear benefit in reducing the risk of getting a TB infection there is emerging evidence that it may reduce its duration. Certain groups of people are at a higher risk of infection with Mycobacterium tuberculosis, the bacterium that causes TB. An important risk group are those with Diabetes Mellitus, who are at an increased risk of both becoming infected and dying from the disease. The reason for this is not clear, however differences in the immune response to Mycobacteria are thought to be important. Strategies to improve protection of high risk groups including those with Diabetes are needed to reduce the global burden of TB.
Localised immune responses can differ to those seen systemically. Vaccine studies in other infectious diseases have shown that altering the route of administration can improve protection from disease. There is also evidence from animal studies that breathing in BCG as a fine mist (aerosol) can make the vaccine more effective than BCG injections. Previous clinical trials in our group (TB041 and TB044) and a current study (TB043) recruited healthy volunteers and showed that aerosol inhaled BCG can be safely administered. It has also been shown that BCG given this way can elicit immunological responses not seen in the systemic blood compartment. Vaccination with BCG through the respiratory tract therefore offers an important alternative to intradermal vaccination, which has the potential to be a more effective route for a boosting vaccine.
This study will provide data on the immune response to booster vaccination with BCG. The investigators will compare how these responses differ between routes of vaccine delivery (aerosol inhaled BCG versus intradermal vaccination), and also explore how the immune response to revaccination differs in adults with Type 2 diabetes (T2DM). The investigators will use the findings to explore the potential benefits of aerosol vaccination and to investigate differences in the immune responses in diabetic individuals to understand how the investigators can improve protection against TB in this high risk group.
It will involve a total of 36 previously BCG-vaccinated participants; 12 healthy volunteers will receive boosting vaccination with aerosol BCG, while a further 12 healthy volunteers will receive a boosting vaccination with intradermal BCG. The investigators will perform washings from the lungs (bronchoscopies) 14 days after BCG vaccination to measure immunological and bacterial responses. A further 12 previously BCG-vaccinated, healthy adult volunteers with T2DM will receive a boosting vaccination with intradermal BCG. The investigators will take blood samples from all volunteers to explore the immune response to BCG and to develop markers to understand who has developed a protective immune response to TB.
1,417 studies on the registry are indexed under Tuberculosis; 208 are open to participants now.
This study's planned enrollment of 36 is below the median of 150 across 952 interventional studies indexed under Tuberculosis.
Browse Tuberculosis studies →University of Oxford is the lead sponsor of 794 studies on the registry; 117 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Group A or B Specific Exclusions:
A1: 6 historically BCG-vaccinated volunteers without type 2 diabetes will receive 2-8 X 10\^5 cfu intradermally injected BCG. A2: 6 historically BCG-vaccinated volunteers without type 2 diabetes will receive 1 x 10\^5 cfu intradermally injected BCG. All Group A volunteers will have a bronchoscopy 14 days post challenge.
Biological: BCG Danish
B1: 6 historically BCG-vaccinated volunteers without type 2 diabetes will receive 2-8 X 10\^6 cfu aerosol inhaled BCG. B2: 6 historically BCG-vaccinated volunteers without type 2 diabetes will receive 1 X 10\^6 cfu aerosol inhaled BCG. All Group B volunteers will have a bronchoscopy 14 days post challenge.
Biological: BCG Danish
C1: 6 historically BCG-vaccinated volunteers with confirmed type 2 diabetes will receive 2-8 X 10\^5 cfu intradermally injected BCG. C2: 6 historically BCG-vaccinated volunteers with confirmed type 2 diabetes will receive 1 X 10\^5 cfu intradermally injected BCG. All Group C volunteers will not have a bronchoscopy.
Biological: BCG Danish
BCG Danish 1331 is on the WHO list of pre-qualified vaccines and has a well-defined side effect profile. BCG is licensed for delivery via the intradermal route. It is not licensed for delivery via the aerosol route.
Intradermal vs. aerosol BCG in non-type 2 diabetics
To compare the immunological response of BCG re-vaccination by the aerosol inhaled route to the intradermal route in healthy historically intradermally BCG-vaccinated volunteers. This will be measured using laboratory markers of innate and adaptive immunity, which may include ex-vivo ELISpot and ELISAs, RNA sequence analysis and intracellular cytokine staining of blood. This will also be measured using flow cytometry, ELISA and cytokine staining of BAL samples. This will be achieved by blood test done at each follow up visit and bronchoscopy to retrieve BAL sample at Day 14 visit for non- diabetic volunteers.
Time frame: Up to day 168
Intradermal (in type 2 diabetics) vs intradermal (in non-type 2 diabetics)
To compare the immunological response of BCG re-vaccination by the intradermal route in historically intradermally BCG-vaccinated volunteers with Type 2 Diabetes and non-diabetic healthy adults. This will be measured using laboratory markers of innate and adaptive immunity, which may include ex-vivo ELISPOT and ELISAs, RNA sequence analysis and intracellular cytokine staining of blood. This will be achieved through the blood test done at each follow up visit.
Time frame: Up to day 168
Intradermal or aerosol BCG re-vaccination safety in healthy volunteers
To describe the safety of intradermal or aerosol BCG as a BCG re-vaccination in healthy UK Volunteers. This will be measured using actively and passively collected data on adverse events and detailed participant symptom profiles throughout the study duration.
Time frame: Up to day 168
Examination of immunological and microbiological markers
To examine immunological and microbiological markers that correlate with increased protection from M.tb infection. This will be measured using laboratory markers of innate and adaptive immunity, which may include the Mycobacterial Growth Inhibition assay on PBMC/serum and on BAL cells, ex-vivo ELISpot and ELISAs, RNA sequence analysis and intracellular cytokine staining of blood. This will also be measured using flow cytometry, ELISA, cytokine staining and other exploratory immunology or microbiology assays on blood or respiratory samples. This will be achieved through blood test and swabs at each follow up visits and bronchoscopy at Day 14.
Time frame: Up to day 168
This study is active, not recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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University of Oxford