Effect of herpes zoster vaccination on dementia occurrence: A quasi-experimental study in Australia.

Michael Pomirchy, Christian Bommer, Fabienne Pradella, Felix Michalik, Ruth Peters, Pascal Geldsetzer

Abstract readPreprint

In one paragraph

Article in medRxiv : the preprint server for health sciences, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

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0citing papers in PubMed

–field-weighted citation impact

1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

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0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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Updated by
Herpes Zoster Vaccination and Dementia Occurrence.2025

5 · Who and what money

Authors and funding

6 authors.

Michael PomirchyDivision of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, California, USA.

Christian BommerDivision of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, California, USA.

Fabienne PradellaDivision of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, California, USA.

Felix MichalikDivision of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, California, USA.

Ruth PetersAgeing and Neurodegeneration, Neuroscience Research Australia, Sydney, Australia.

Pascal GeldsetzerDivision of Primary Care and Population Health, Department of Medicine, Stanford University, Stanford, California, USA.ORCID 0000-0002-8878-5505

Funding

The impact of clinical interventions for sepsis in routine care and among detailed patient subgroups: A novel approach for causal effect estimation in electronic health record dataDP2AI171011 · NIAID · STANFORD UNIVERSITY · PI Pascal Geldsetzer · 2022 to 2026

$2.4M

The effect of antihypertensive and statin therapy on dementia incidence: a novel analytical approach in large electronic health record datasets with long follow-up times and minimal loss to follow-upR01AG084535 · NIA · STANFORD UNIVERSITY · PI Pascal Geldsetzer · 2024 to 2026

$2.2M

NIAID NIH HHS DP2 AI171011NIA NIH HHS R01 AG084535

6 · The paper itself

Abstract

Importance: Taking advantage of a natural experiment in Wales, our group has recently provided evidence that herpes zoster (HZ) vaccination appears to prevent or delay dementia. Exploiting a similar natural experiment in Australia, this present study investigated the effect of HZ vaccination on dementia occurrence in a different population and health system setting. Objective: To determine the effect of HZ vaccination on the probability of receiving a new diagnosis of dementia in the future. Design Setting and Participants: In Australia, starting on November 1 2016, live-attenuated HZ vaccination was provided for free to individuals aged 70 to 79 years of age through primary care providers. Thus, those whose 80 Exposure: Eligibility for HZ vaccination based on one's date of birth. Main outcome: New diagnoses of dementia as recorded in primary care electronic health record data. Results: As expected, in our sample of 101,219 patients, individuals born just before versus shortly after the date-of-birth eligibility threshold (November 2 1936) for HZ vaccination were well-balanced in their past preventive health services uptake and chronic disease diagnoses. There was an abrupt increase of 16.4 (95% CI: [13.2 - 19.5], p < 0.001) percentage points in the probability of ever receiving HZ vaccination between patients born shortly before versus shortly after the date-of-birth eligibility threshold. The eligibility rules of the HZ vaccination program, thus, created comparison groups just on either side of the date-of-birth eligibility threshold who were likely similar to each other, except for a large difference in their probability of receiving the intervention (HZ vaccination) of interest. Drawing on a sample of 18,402 patients, we find that eligibility for HZ vaccination (i.e., being born shortly after versus shortly before November 2 1936) decreased the probability of receiving a new dementia diagnosis over 7.4 years by 1.8 percentage points (95% CI: [0.4 - 3.3], p = 0.013). Being eligible for HZ vaccination did not affect the probability of taking up other preventive health services (including other vaccinations), nor the probability of being diagnosed with other common chronic conditions than dementia. Conclusions and Relevance: Corroborating our quasi-experimental findings from Wales in a different population, this study provides important evidence on the potential benefits of HZ vaccination for dementia because its quasi-experimental design allows for conclusions that are more likely to be causal than those of more commonly conducted associational studies.

Identifiers

PMID38978672

DOI10.1101/2024.06.27.24309563

PMCPMC11230318

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