An article published in Nature presents a new piece of evidence to bolster the growing impression that vaccination against varicella zoster virus can provide protection against dementia, a disease not traditionally attributed to infection.
The authors draw on a natural experiment: In Wales, in the United Kingdom, eligibility for a live-attenuated zoster vaccine was determined on the basis of an exact birth date, allowing the investigators to compare groups just before versus just after the cutoff date. The comparison of closely related groups, totaling 282,541 individuals with different eligibility for zoster vaccination, showed that the probability of dementia diagnosis over a seven-year follow-up period was reduced by 3.5% in those who received zoster vaccination (absolute risk reduction, 3.5%; 95% confidence interval, 0.6% to 7.1%; and relative risk reduction, 20.0%; 95% CI, 6.5% to 33.4%). The observed effect was stronger among women than men.
The results from this Welsh cohort build on a growing body of evidence that suggests VZV vaccination can protect against dementia, including vaccination with recombinant VZV vaccines, as highlighted in an article published in Nature Medicine.