SEMINAR: Boosting immune resilience to newborn sepsis with the pathogen-agnostic effects of BCG

The newborn period, or the first 30 days of life, is the most vulnerable time in the human lifespan with sepsis, or severe infections, a leading cause of newborn death. Globally, over 3 million newborns are diagnosed with sepsis each year, and up to 19% of them die. Vaccines have worked miracles in reducing mortality in later childhood by focussing on the pathogen – in other words, one vaccine for one microbial threat. Unfortunately, there are too many different pathogens that infect newborns, making specific vaccines for each one not feasible. Thankfully, emerging evidence suggests that boosting immune resilience to many pathogens at once is possible. For example, research done by the Bandim Health Project in Guinea Bissau showed that Bacille Calmette Guerin (BCG), the vaccine against tuberculosis, reduces newborn mortality even when no tuberculosis is present. We identified how BCG, within days of being given, boost levels of newborn white blood cells that fight a wide range of invading pathogens. Our current work is focussed on optimizing this effect, as it does not work for all newborns. Early findings suggest that this relates to the metabolic state of the newborn. We anticipate that insight into the underlying mechanisms that ‘license’ BCG to work will offer opportunities to make BCG work for all - immune equity in action.