One of the largest studies of its kind has found compelling evidence linking shingles vaccination to a lower risk of dementia, offering hope in the fight against one of the world’s fastest-growing health threats.
Experts examine health records of more than 280,000 individuals in Wales, UK, found that those who received the vaccine for the varicella zoster virus, which causes shingles, had a 20% lower risk of developing dementia over a seven-year span compared to those who were not vaccinated.
The findings, published in Nature, originated from what scientists refer to as a “natural experiment” resulting from Wales’ vaccination policy in 2013. That year, the Zostavax vaccine was offered to individuals aged 79 but excluded those who had just turned 80 due to logistical issues. This unintended age difference created a unique opportunity for researchers to examine two similar groups.
This is an important finding,” remarked one of the lead authors of the study. “The magnitude of the protective effect, especially among women, is impressive and indicates that shingles vaccination may be an effective strategy for lowering the risk of dementia.
Shingles occurs when the varicella zoster virus, which remains inactive in nerve cells after a childhood chickenpox infection, becomes reactivated. Experts suggest that preventing this reactivation could help lessen brain inflammation, a recognized factor associated with cognitive decline and dementia.
Although the older Zostavax vaccine has been discontinued in numerous countries due to the introduction of the more effective Shingrix vaccine, recent findings indicate that Shingrix may have an even greater protective effect against dementia. Additionally, a separate study published in Nature Medicine last year revealed that individuals who received Shingrix experienced up to a 23% lower risk of developing dementia compared to those who were vaccinated with Zostavax.
Considering the increasing impact of dementia around the world—affecting 57 million individuals globally in 2021, as reported by the WHO—experts indicate that the consequences are significant.
The experts concluded that “given our significant effect sizes and the relatively low price of the zoster vaccine, if these results are genuinely causal, the zoster vaccine would prove to be much more effective and cost-efficient in preventing or delaying dementia compared to current pharmaceutical treatments.”
With almost 10 million new dementia cases identified annually, especially in low- and middle-income nations, experts are urging for additional research to validate these results and possibly revise global vaccination approaches.
