ICMR to begin study to evaluate BCG booster dose for kids, adolescents

CHENNAI: Scientists at ICMR’s National Institute for Research in Tuberculosis in Chennai plan to initiate a study on BCG booster dose for kids and adolescents, who are household contacts of tuberculosis patients. The study aims to understand whether a booster BCG dose would prevent development of tuberculosis among them. For this, more than 9,000 children will be enrolled across seven sites in India.

The primary aim of this study is to assess the efficacy of BCG re-vaccination compared to oral chemoprophylaxis in preventing tuberculosis (TB) in household contacts aged 6-18 years. Children will be randomized into 2 study groups: BCG and  Oral chemoprophylaxis.

Bacille Calmette Guerin (BCG) vaccine is one of the most widely used vaccines in the world to reduce risks of natural tuberculous infection. The efficacy of BCG vaccination in newborns is well known and has a documented protective effect against meningitis and disseminated TB in children.

However, there is considerable uncertainty on BCG revaccination. It is known that BCG revaccination enhances immune responses, but it is yet to be established if BCG revaccination can help prevent TB disease in household contacts.

“The study is designed as a multicenter randomized controlled trial with two groups of healthy household contacts aged 6-18 years receiving either the BCG vaccine or oral chemoprophylaxis. They will be followed up for 24 months to compare the incidence of TB disease in each arm. This study will demonstrate the effect of BCG revaccination in comparison to oral chemoprophylaxis on the incidence of mycobacterium tuberculosis disease in healthy household contacts, aged 6-18 years,” Dr C Padmapriyadarsini, Director, NIRT told Mint.

“ICMR has held one round of talk with the health ministry and another meeting is scheduled for next week. As of now, there is no reported data of how many children develop TB in this age group and how many die due to the disease,” Dr C Padmapriyadarsini said.

“All children will be household contacts of microbiologically confirmed pulmonary TB patients. Contacts of Multidrug-resistant (MDR) TB adults will also be included in the study. Both C-Tb skin test positive and negative children will be included. Similarly, both well-nourished and malnourished children will be included. All children will be followed up for 24 months post recruitment and the incidence of TB (all forms) will be compared between the groups. TB will be diagnosed as per the National TB Elimination Program (NTEP) and Latent TB infection (LTBI) will be based on the C-TB skin test results.

Scientists are aiming to start the study as early as possible as they are waiting for fund release. They have targeted to complete the study by 2025 to match the health ministry’s deadline of TB elimination target by 2025.