Role of BCG as Booster Vaccination

Study Overview
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Brief Summary
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The BCG (bacillus Calmette-Guerin) vaccine is used for the protection against tuberculosis. Apart from it's protective effect against tuberculosis BCG vaccine has been shown to have non-specific effects on the innate immune system and is in epidemiological studies associated with reduced mortality due to infectious diseases. Several studies have shown that BCG can boost the effect of other vaccines. The present study aims to investigate the boosting effect of BCG on the response to typhoid fever vaccine (TFV) and to assess the non-specific effects of BCG on the innate immune system at early timepoints by vaccinating volunteers with either TFV alone or BCG followed by TFV 14 days later. The study hypothesis is that when BCG is given 14 days before typhoid fever vaccine a better vaccination result in terms of antibody production will be accomplished against typhoid fever due to the effects of BCG on the innate immune system.

Official Title
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Role of BCG Vaccination as Booster on Salmonella Typhi Vaccine

Conditions
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BCG Vaccination

Intervention / Treatment
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* Biological: BCG
* Biological: TFV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers Exclusion Criteria: Born in Salmonella typhi endemic country Pregnancy Oral medication except anticonceptive drugs Previous vaccination with BCG and/or TFV

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: TFV alone<br>Typhim Vi | Biological: TFV<br> <br> * Other names: Typhim Vi;|
| Experimental: BCG+TFV<br>BCG (SSI, Denmark) followed after 14 days by Typhim Vi | Biological: BCG<br> <br> * Other names: BCG vaccine (SSI, Denmark);Biological: TFV<br> <br> * Other names: Typhim Vi;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| anti-salmonella typhi Vi antigen antibody titer 2 weeks post TFV | anti-salmonella typhi Vi antigen antibody titers at 2 weeks after TFV will be compared between TFV only and TFV after BCG groups. | 2 weeks | 
| anti-salmonella typhi Vi antigen antibody titer 3 months post TFV | anti-salmonella typhi Vi antigen antibody titers at 3 months after TFV will be compared between TFV only and TFV after BCG groups. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in ex vivo cytokine responses | Ex vivo cytokine response to unrelated antigens | 0, 1 and 4 days; 2 weeks, 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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BCG, Salmonella, Trained immunity, Non-specific effect vaccines