Immunological Insights into Healthy Aging: The Impact of BCG Vaccination

Maintaining a robust immune system is key to healthy aging. This thesis explores how the immune system changes with age and proposes ways to counteract it. The first part showed that individuals from Tanzania and the Netherlands experience immune aging differently, partially due to diet. We identified multiple molecules linked to a stronger immune system in old age and showed that immune aging differs for men and women. 
The second part focused on counteracting immune aging by inducing “trained immunity”: the immune system's memory of past exposures resulting in a better response to future threats, even if they differ from the original. BCG vaccination is a safe way to induce trained immunity. Our studies identified a natural compound that improves BCG’s effect and a common osteoporosis medication that suppresses it. Overall, this work provides new insights into promoting a healthy immune system in older adults.