India needs innovative strategies to eliminate TB, Pg10

Key Highlights:

• India faces one of the world's highest Tuberculosis (TB) burdens, aiming for elimination.
• The PreVenTB trial, conducted by the Indian Council of Medical Research (ICMR) across 18 sites in India, evaluated VPM1002 and Immuvac vaccines.
• VPM1002 showed 50.4% efficacy against extrapulmonary TB (EPTB) and 64.6% efficacy in children aged 6-14 years against all TB forms.
• Immuvac demonstrated over 60% efficacy against EPTB in children aged 6-10 years.
• The trial highlighted the importance of nutritional support, as reduced vaccine efficacy was observed in individuals with low Body Mass Index (BMI).

Detailed Insights:

• Tuberculosis remains a leading infectious killer globally, with no effective vaccine for adolescents and adults despite its long history.
• The disease manifests in diverse ways, including latent infection, subclinical disease, pulmonary TB (PTB), and extrapulmonary TB (EPTB), making a single "one-shot" vaccine challenging.
• India's TB elimination goal requires a holistic strategy encompassing better detection, preventive therapy, and vaccination, moving beyond the search for a perfect solution.
• The PreVenTB trial is significant as it is the first to study vaccine efficacy against both PTB and EPTB in individuals aged six years and above under real-world conditions.
• Extrapulmonary TB is a hidden burden, often misdiagnosed, and associated with high morbidity and mortality, making a 50% reduction clinically and publicly impactful.
• The strong efficacy signal in school-age children and adolescents could pave the way for a booster-dose TB prevention strategy in India, which currently lacks one beyond infancy.

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• VPM1002, a single-dose vaccine based on a modified BCG platform, offers logistical simplicity and cost-effectiveness, crucial for large-scale deployment in India.
• India has a precedent for adopting moderately effective indigenous solutions, as seen with TrueNat, Covaxin, and rotavirus vaccines, to address urgent public health needs.
• A smarter TB strategy involves integrating moderately effective vaccines with targeted use among high-risk groups, nutritional support, and preventive therapy programs.

Key Concepts Involved:

• Tuberculosis (TB): An infectious disease caused by Mycobacterium tuberculosis, primarily affecting the lungs but capable of impacting other organs.
• Pulmonary TB (PTB): The infectious form of TB that primarily affects the lungs and is responsible for transmission.
• Extrapulmonary TB (EPTB): TB that affects organs other than the lungs, often harder to diagnose and more debilitating.
• Latent TB Infection: A state where Mycobacterium tuberculosis is present in the body without causing active disease symptoms.