Public Health.

Background: Using a unique natural randomization, we have recently provided evidence from Welsh electronic health record data that herpes zoster (HZ) vaccination caused a reduction in new dementia diagnoses over a seven-year period. This study aimed to determine whether eligibility for HZ vaccination also caused a reduction in deaths due to dementia in England and Wales over a nine-year follow-up period.

Methods: Adults who had their 80 birthday shortly before September 1 2013 were ineligible for free HZ vaccination and remained ineligible for life, whereas those who had their 80 birthday shortly after September 1 2013 (i.

The effect of herpes zoster vaccination at different stages of the disease course of dementia: Two quasi-randomized studies.

The varicella zoster virus, a neurotropic herpesvirus, has been hypothesized to play a role in the pathophysiology of dementia, such as through neuroinflammatory processes or intracerebral vasculopathy. Using unique natural experiments, our group has previously found that live-attenuated herpes zoster (HZ) vaccination reduced the incidence of new diagnoses of dementia in both Wales and Australia. To inform further research and ultimately clinical care, it is crucial to understand at which stage of the disease course of dementia the HZ vaccine has its effect.

The effect of herpes zoster vaccination on the occurrence of deaths due to dementia in England and Wales.

Background: The United Kingdom (UK) has used date of birth-based eligibility rules for live-attenuated herpes zoster (HZ) vaccination that have led to large differences in HZ vaccination coverage between individuals who differed in their age by merely a few days. Using this unique natural randomization, we have recently provided evidence from Welsh electronic health record data that HZ vaccination caused a reduction in new dementia diagnoses over a seven-year period. Based on this, we hypothesized that HZ vaccination may have slowed the dementia disease process more generally and, thus, already reduced deaths with dementia as their underlying cause even though the UK's HZ vaccination program commenced as recently as September 2013.

Causal evidence that herpes zoster vaccination prevents a proportion of dementia cases.

The root causes of dementia are still largely unclear, and the medical community lacks highly effective preventive and therapeutic pharmaceutical agents for dementia despite large investments into their development. There is growing interest in the question if infectious agents play a role in the development of dementia, with herpesviruses attracting particular attention. To provide causal as opposed to merely correlational evidence on this question, we take advantage of the fact that in Wales eligibility for the herpes zoster vaccine (Zostavax) for shingles prevention was determined based on an individual's exact date of birth.