Routine vaccines may cut dementia risk—experts have a startling hypothesis on how

New studies suggest several routine vaccines may be linked to a lower risk of dementia.

Shingles vaccination shows one of the strongest associations, with flu, RSV, Tdap, pneumococcal, hepatitis A/B, typhoid, and BCG vaccines also under review.

Researchers think the benefit may come from trained immunity, in which vaccines create lasting epigenetic changes in innate immune cells.

If confirmed, the finding could help explain a brain-health benefit of vaccination and point to new ways to prevent or delay dementia.