Young children are a vulnerable population and critical research questions, especially in the field of TB, remain unanswered. For example, TB brain infection or TB meningitis disproportionately affects young children, and leads to very high mortality. Yet, little is known about how this disease occurs and how to treat / prevent it. Major concerns for Pediatric TB include our inability to make a definite diagnosis, lack of information on how to treat TB and ineffective vaccines. Our group has therefore focused on developing better diagnostics and vaccines for TB. Specifically, we focus on entirely novel technologies - non-invasive imaging – that overcome some fundamental limitations of current microbiologic methods (M.tb. is difficult to isolate in children especially for brain infections and even when it can be isolated, diagnosis often take several weeks) for diagnosing infections. Essentially, our goals are to definitely diagnose an infection, provide information about what kind of infection it is, and may be also provide information about drug-susceptibilities, quite rapidly and non-invasively. This information is critical in appropriate management of infections and broadly applicable to other infections beyond TB.
Since lungs are the predominant site for TB and pulmonary disease is required for TB transmission, there is a perception in the TB research community that current resources should be only be channelled for the development of TB vaccines that prevent pulmonary disease, which has proven to be very challenging. While this is justifiable, TB brain infection (including meningitis) during early childhood leads to significant morbidity and mortality. The current WHO recommendation for administration of the BCG vaccine at birth are based due to the protection conferred by BCG against severe forms of TB such as TB meningitis during infancy. However, BCG is a live vaccine, and therefore unsuitable for immunosuppressed infants especially in the setting of HIV. This is important as HIV is driving the TB epidemic in several parts of the world. Moreover, BCG is not well-defined antigenically, and the several different BCG strains offer variable levels of protection. An additional limitation is that BCG confounds the interpretation of the tuberculin skin test. None of these limitations would apply to subunit vaccines such as the one described in our study. So while efforts should continue to develop a TB vaccine against pulmonary infection and disease, we should not forget the urgent need for a better vaccine against severe forms of TB, such as TB meningitis, during infancy. Learn more about Dr. Jain