Vaccines May Slow Dementia: A Welsh Natural Experiment Sparks New Hope

A 2013 Welsh, age-based shingles-vaccine rollout created a natural experiment showing people offered the vaccine were about 20% less likely to develop dementia, with some data suggesting vaccines might also slow progression in those already with dementia. Across multiple vaccines (influenza, BCG, shingles, and others) there are growing links to lower dementia risk, likely via trained immunity that broadens immune protection. While promising, dementia vaccines face past trial failures and require coordinated, long-term research and funding before they can become a widespread preventive strategy.