Identifying transcriptomic signatures of BCG-induced protection against heterologous infections in infants

BCG vaccination is usually given to provide protection against tuberculosis.

Increasing evidence suggests that it also protects against other infections, particularly in babies in countries with high rates of childhood infections and deaths. Exactly how BCG provides this non-specific protection is unclear.

In this study I will investigate whether BCG changes the activity of blood cells in newborns, and whether the pattern of these changes identifies which babies will be protected from infections (other than tuberculosis) when they are older.

To do this I will measure the levels/patterns of RiboNucleic Acid (RNA: the messenger signal that directs the creation of proteins from genes, determining the function/activity of cells) in blood collected during a study where babies were allocated at random to receive BCG at birth or at 6-weeks of age.

Blood collected at birth and day 5 from babies in three groups will be examined: 1. Babies who remained well during follow-up (21 BCG-vaccinated, 14 not BCG-vaccinated) 2. Babies who had a serious infection during follow-up (3 BCG-vaccinated, 4 not BCG-vaccinated) 3.

Babies who had a cold during follow-up (10 BCG-vaccinated, 11 not BCG-vaccinated) By comparing the RNA levels between these groups, changes caused by BCG that predict protection against later infections may be identified.

Discovering changes in blood associated with BCG’s protection against diseases other than tuberculosis will have valuable research benefits, simplifying and directing future studies.

The work could also directly help children by suggesting new interventions or diagnostic tests for babies at risk of serious infections.