# Research timeline and gaps: Shingles Vaccination and Dementia Prevention

Selected publication milestones, not an exhaustive history or discovery priority claim.

**1998 — 1998 SystEur reports a small randomized dementia-prevention signal for a BP regimen.** [Original PMID9802273](https://pubmed.ncbi.nlm.nih.gov/9802273/).

**2008 — 2008 HYVET lowersBP but not significant dementia over its early-terminated horizon.** [Original PMID18614402](https://pubmed.ncbi.nlm.nih.gov/18614402/).

**2016 — 2016 influenza/CKD observational protection extends beyond infection season.** [Original PMID26945371](https://pubmed.ncbi.nlm.nih.gov/26945371/).

**2018 — 2018 Taiwanese HZ/antiviral associations motivate prevention hypotheses.** [Original PMID29244265](https://pubmed.ncbi.nlm.nih.gov/29244265/).

**2019 — 2019 SPRINT separates positive MCI/composite outcomes from nonsignificant probable dementia.** [Original PMID30688979](https://pubmed.ncbi.nlm.nih.gov/30688979/).

**2020 — 2020 ASPREE aspirin finds no cognitive/dementia benefit.** [Original PMID32213642](https://pubmed.ncbi.nlm.nih.gov/32213642/).

**2022 — 2022 Welsh ordinary cohorts explicitly retain healthy-life-expectancy selection.** [Original PMID35434253](https://pubmed.ncbi.nlm.nih.gov/35434253/).

**2022 — 2022 UK overt-zoster/dementia association is null or inverse.** [Original PMID35170873](https://pubmed.ncbi.nlm.nih.gov/35170873/).

**2022 — 2022 neural cultures demonstrate VZV–HSV1 reactivation with AD-like markers.** [Original PMID35754275](https://pubmed.ncbi.nlm.nih.gov/35754275/).

**2024 — 2024 product-transition analysis reports more dementia-diagnosis-free time after RZV.** [Original PMID39053634](https://pubmed.ncbi.nlm.nih.gov/39053634/).

**2025 — 2025 Welsh birth-date natural experiment identifies a local live-vaccine causal signal.** [Original PMID40175543](https://pubmed.ncbi.nlm.nih.gov/40175543/).

**2025 — 2025 Australian eligibility design corroborates a positive diagnosis contrast.** [Original PMID40267506](https://pubmed.ncbi.nlm.nih.gov/40267506/).

**2025 — 2025 AS01-adjuvanted RSV/zoster cohorts suggest a possible immune pathway.** [Original PMID40562756](https://pubmed.ncbi.nlm.nih.gov/40562756/).

**2025 — 2025 randomized hypertension care lowers incident all-cause dementia.** [Original PMID40258956](https://pubmed.ncbi.nlm.nih.gov/40258956/).

**2026 — 2026 Canadian eligibility contrasts extend geography while separate uptake and interaction limits remain.** [Original PMID41579903](https://pubmed.ncbi.nlm.nih.gov/41579903/).

**2026 — 2026 nursing-facility RZV emulation retains residual negative-control confounding.** [Original PMID42296498](https://pubmed.ncbi.nlm.nih.gov/42296498/).

**2026 — 2026 quantitative reanalysis challenges implied causal magnitudes outside Wales.** [Original PMID42754179](https://pubmed.ncbi.nlm.nih.gov/42754179/).

## Research gaps

Resolve implausible international implied receipt effects and weak separate-survey first stages with individual-level local data.

Direct preventive efficacy of recombinant vaccination rather than ordinary vaccinee cohorts.

Biological onset versus delayed clinical diagnosis and competing-death effects.

Prespecified age/product/sex boundaries with formal interaction tests.

Separate infection suppression, heterologous immune effects and healthcare pathways.

Drug-specific clinical prevention rather than class transfer from surrogate or observational successes.

## Boundary experiment

Combine an ethically designed randomized timing/product or vaccine-encouragement comparison within clinically permitted practice with adjudicated incident dementia, active comparators and competing-death analyses. Prespecify product, age and sex, assess baseline cognition and healthcare contacts, and separately reproduce eligibility estimates using individual uptake and counterfactual complier risks. A mechanistic substudy must distinguish viral reactivation from adjuvant immunity without replacing clinical endpoints.