A Welsh birthdate cutoff linked shingles vaccination to fewer new dementia diagnoses, then to fewer dementia-related deaths among people already diagnosed, but the later estimate was imprecise and neither study makes the vaccine a dementia treatment.
A natural experiment involving more than 280,000 Welsh adults found that shingles vaccination cut new dementia diagnoses by 20% over seven years. Months later, the same researchers found something even stranger: the apparent benefit extended to people who already had dementia, who were less likely to die from the disease.
The Long View