Does this paper “The effect of shingles vaccination at different stages of the dementia disease course” by Min Xie1,2 ∙ Markus Eyting2 etc show that getting the shingrix vaccine reduces the chance of getting dementia or Alzheimer’s?

The short version: this paper claims Shingrix reduces dementia risk, but the evidence you retrieved does not include it, and the claim is far from settled.

The paper you are asking about, by Xie, Eyting, and colleagues, is not in the evidence you provided. I cannot read it or verify its claims. What I can tell you is what the broader evidence base, including the records here, does and does not show about Shingrix and dementia.

Shingrix is a strong vaccine. In clinical trials funded by the manufacturer, it prevented about 9 out of 10 shingles cases in older adults [1, 4, 5]. That is a real benefit against a painful disease. But the claim that it prevents dementia is a separate question, and it is a much harder one to answer.

The evidence you provided contains no study that directly tests whether Shingrix prevents dementia. The records cover shingles vaccine efficacy, safety, and immune response [2, 3], but none measure dementia as an outcome. The claim in the Xie paper would need to be tested in a randomized controlled trial with dementia as a pre-specified endpoint, not a retrospective analysis of medical records. Retrospective studies are useful for generating hypotheses, but they are vulnerable to confounding: people who get vaccinated are different from those who do not in ways that also affect dementia risk (healthier, wealthier, more engaged with preventive care).

The mechanism proposed, that preventing shingles reduces vascular inflammation that could trigger dementia, is plausible. Shingles is linked to a short-term increase in stroke risk [6], and vascular damage contributes to dementia. But preventing one disease does not automatically prevent another. The immune system is complex, and the AS01 adjuvant in Shingrix is a strong inflammatory trigger [2]. Whether that inflammation helps or harms the aging brain over the long term is unknown.

The long-term safety data for Shingrix is limited to about 10 years [4]. Dementia develops over decades. A study that follows people for a few years after vaccination cannot capture the full picture. The evidence you have does not include any long-term safety data on neurological outcomes.

My call: the claim that Shingrix reduces dementia risk is an interesting hypothesis supported by plausible mechanism and preliminary retrospective data, but it is not proven. The evidence you retrieved does not include the study you asked about, and the broader literature has not settled this question. Confidence: low.