Search

18 May 2016 Biomarker study provides insight into TB disease risk in young children

18 May 2016 - 21:30

A team of scientists from the South African Tuberculosis Vaccine Initiative (SATVI) at the University of Cape Town, in collaboration with multiple international research groups, have made a discovery that enhances understanding of how the Bacille Calmette-Guérin (BCG) vaccine stimulates our immune systems to protect against tuberculosis (TB).

A team of scientists from the South African Tuberculosis Vaccine Initiative (SATVI) at the University of Cape Town, in collaboration with multiple international research groups, have made a discovery that enhances understanding of how the Bacille Calmette-Guérin (BCG) vaccine stimulates our immune systems to protect against tuberculosis (TB). The main finding was that the immune systems of different groups of infants respond differently to the BCG vaccine, implying that different mechanisms of protection against TB may exist within a population. Mechanisms underlying the distinct responses were described, and included differences in innate immune cell numbers.


TB remains one of the world’s major killer diseases, infecting 9.6 million people and killing 1.5 million in 2014. The only available vaccine, Bacillus Calmette-Guérin (BCG), is very safe and protects against severe TB disease in babies and should therefore be given to newborns. However, the vaccine’s protection against lung disease, which spreads the bacterium, is variable and mostly poor. Control of the TB epidemic is unlikely without a new vaccine that would prevent lung disease effectively. The research team, funded by the NIH, EDCTP, European Commission, Bill and Melinda Gates Foundation and Aeras, set out to learn more about how BCG may protect against TB.


Professor Willem Hanekom, the principal investigator, said: “The study results have important implications for new vaccine development, as we would have to take into account that the vaccine may work through distinct mechanisms in different persons from the same population.” The team used advanced techniques to measure gene expression, cell types and their function in the blood of BCG vaccinated healthy infants to identify differences that could predict the development of TB disease in those not protected by the vaccine. They showed that some of the infants who got sick from TB later on had a stronger T cell response to the vaccine in presence of elevated levels of anti-inflammatory monocytes, which may be involved in the pathogenesis of tuberculosis.

Read Scientific Abstract. Click here.