Shingles Vaccine Linked to Reduced dementia Risk in Major Observational Study
Cardiff, Wales – A large-scale observational study in Wales suggests a surprising benefit of the shingles vaccine: a notable reduction in dementia-related deaths among those already diagnosed with the condition. Researchers, led by Dr. Peter Geldsetzer at Stanford University, have consistently observed this protective effect across multiple international datasets, raising the possibility that the vaccine could not only prevent but also slow the progression of dementia.
The study, initially published in December, examined the health records of 7,049 Welsh seniors who had a dementia diagnosis at the start of the national shingles vaccination program. Results revealed a striking difference in outcomes. While nearly half (approximately 3,525) of the dementia patients died of dementia during the nine-year follow-up period, the rate dropped to around 30 percent among those who received the shingles vaccine. This suggests the vaccine may have slowed the disease’s progression.
“The most exciting thing about this is that this really suggests that the herpes zoster vaccine not only has preventive and delaying benefits for dementia, but also therapeutic potential for those who already have dementia,” Dr. Geldsetzer stated to Stanford Medicine.
The unique rollout of the Welsh vaccination program – offering the vaccine to all seniors nonetheless of shingles history – is cited as a strength of the study. Researchers believe this broad approach minimizes potential bias in the analysis.
The protective mechanism remains unclear. Scientists are investigating whether the vaccine’s benefits stem from a general immune system boost, reduced reactivation of the varicella-zoster virus (which causes both shingles and chickenpox), or an entirely different pathway. It is indeed also unknown if newer, more effective shingles vaccines utilizing only specific viral proteins would yield even stronger results.
Dr. Geldsetzer’s team has since reviewed health data from England, Australia, New Zealand, and Canada, finding consistent ”strong protective signal[s] for dementia” across these datasets.
The next crucial step, according to researchers, is a large-scale randomized controlled trial. This study would involve randomly assigning participants to receive either the live shingles vaccine or a placebo, offering a definitive test of the vaccine’s impact on dementia risk. “It would be a very simple,pragmatic study because we have a one-time intervention that we know is safe,” Dr. Geldsetzer explained.
Source: lpi