Old TB vaccine tested for brain health clues in seniors

This small pilot study tested whether a single dose of the BCG vaccine, commonly used against tuberculosis, could change markers in the blood and spinal fluid related to brain health and the immune system in older adults. It enrolled 20 participants, some with normal thinking and some with mild memory problems, to see if the vaccine was safe and caused measurable biological changes. The main goal was to gather initial data on how the body and brain respond to BCG, not to treat or prevent a specific disease.