The century-old Bacillus Calmette-Guérin (BCG) vaccine has been administered to billions of people around the world in an effort to erase tuberculosis, the dreaded and once-widespread bacterial lung disease.
Doctors have long noticed a possible connection between the jab and reduced risk of another dreaded disease: Alzheimer’s.
Now, according to researchers based at Massachusetts General Hospital and Harvard University in the United States, there is a “potential biological explanation” for what the team says were “previously observed associations”.
The jab “changed how immune cells behaved, including in the fluid surrounding the brain and spinal cord, and altered markers linked to Alzheimer’s disease”, the researchers say in a paper published recently in the journal Communications Medicine following two decades of research.
The BCG vaccination alters the brain’s immune response to leave people less likely to develop the debilitating neurodegenerative disease, according to the scientists.
The findings hint at unseen connections between the brain and the immune system that could pave the way for more treatments for other conditions.
“The immune system and the brain may be far more connected than we once thought,” says study senior author and Mass General Brigham Neuroscience Institute Interdisciplinary Brain Center managing director Prof Dr Steven Arnold.
“Although more research is needed, these findings suggest they may also influence biological processes involved in brain ageing and neurodegenerative disease,” says study lead author Dr Mark Weinberg. – dpa
