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GC#6-74 Biomarkers of Protective Immunity Against TB in the Context of HIV/AIDS in Africa
Tuberculosis (TB) is a major health problem, disproportionally affecting the developing world. It is estimated that one third of the global population is infected with the tubercle bacillus. None of the current control measures consider the enormous latent reservoir of TB that keeps perpetuating the epidemic.
The goal of our GCGH project is to identify biomarkers with prognostic potential, which will be crucial for designing and testing improved vaccines that protect people with latent infection from developing TB disease.
Sophisticated molecular and immunological tools will be used to study (i) immune responses against the tubercle bacillus during natural infection in endemic populations in Africa, (ii) the impact of progressive HIV-1 infection and its treatment in immunity against TB as well as (iii) immune responses evoked by vaccination with BCG and novel TB vaccine candidates. This will enable the identification of biomarkers needed to facilitate and optimize the development of new TB vaccines.
Background of problem – Tuberculosis
TB is a major health problem especially in low income countries. Each year it is estimated that more than 8 million people develop TB with over 2 million deaths. Based on tuberculin skin-test surveys it is estimated that one third of the global population is already latently infected with Mycobacterium tuberculosis (Mtb). Typically, only 1 in 10 infected individuals will develop TB disease during lifetime, but with progressive HIV-1 coinfection the risk increases about 8% per year. In Africa, HIV-1 has been the single most important factor in determining the increased incidence of TB in the past 10 years.
Despite major efforts to implement effective treatment strategies for TB patients and the widespread use of the vaccine Bacille Calmette-Guérin (BCG) in young infants, none of the current TB control measures appear to address the issue of the enormous reservoir of latent TB that keeps perpetuating the epidemic. From a public health point of view the development of novel TB interventions, in particular post-exposure vaccines that will eradicate latent TB, are expected to be very cost-effective in global TB control and will complement current treatment strategies.