The Bacillus Calmette-Guérin (BCG) vaccine is known to induce "trained immunity," a form of long-lasting reprogramming of innate immune responses.In a pilot study, BCG changed how immune cells behaved and altered biomarkers in people without Alzheimer's pathology.The next step is a large randomized trial to determine whether BCG can reduce risks of cognitive decline or Alzheimer's disease.
The bacillus Calmette-Guérin (BCG) vaccine, commonly used against tuberculosis, changed how immune cells behaved and altered markers linked to Alzheimer's disease in a pilot study involving two open-label trials.
In a year-long study, BCG vaccination induced persistent, trained immunity-like changes in cerebrospinal fluid (CSF), including enhanced innate immune responsiveness, reported Steven Arnold, MD, of Massachusetts General Hospital in Boston, and co-authors in Communications Medicine.
In participants without Alzheimer's-related pathology at baseline, the immune changes were accompanied by decreased amyloid-beta levels in CSF and increased amyloid levels in blood. This shift was not seen in participants who had Alzheimer's pathology, suggesting that the timing of BCG administration might affect early Alzheimer's dynamics and protein clearance from the central nervous system, the researchers noted.
