Older Adults Vaccinated Against Shingles Have Lower Dementia Risk, A New Study Says

On a crisp autumn morning in Toronto, Maria Santos, an energetic 68-year-old retiree, awaits her routine check-up. Unlike many of her friends, who often lament memory lapses and cognitive confusion, Maria feels sharp and spry, crediting her vitality to a simple decision made years ago: receiving the shingles vaccine. Recent evidence suggests she may not be alone in her fortuitous choice. A study published in The Lancet has unveiled compelling links between shingles vaccination and a reduced risk of dementia among older adults.

The Vaccine Beyond Shingles

With the rise of studies connecting medical interventions to broader health benefits, the shingles vaccine, primarily known for preventing herpes zoster, has drawn increasing scrutiny. Research indicates that vaccination may not only mitigate shingles but could also provide protective effects against serious conditions such as cardiovascular diseases and cognitive decline.

“There’s a fascinating trend in recent years,” says Dr. Pascal Geldsetzer, a lead researcher and assistant professor at Stanford University. “We have found correlations suggesting that vaccination can lead to a significant reduction in dementia risk.” In his study, he and his team analyzed nearly 230,000 health records of older adults in Ontario, Canada. The results confirm a protective relationship that had long been suspected.

The Study: Methodology and Findings

Launched in September 2016, Ontario’s shingles immunization program offered the live-attenuated single-dose herpes zoster vaccine—Zostavax—to adults aged between 65 and 70. Through this program, researchers categorized participants into three pivotal groups:

• Individuals born before January 1, 1945, and ineligible for the vaccine.
• Individuals born in 1945, eligible for the vaccine from September through December 2016.
• Individuals born between January 1, 1946, and September 15, 1951, who qualified for the vaccine for approximately 15.5 months.

The study, which ran over 5.5 years, revealed that those eligible for the shingles vaccine experienced a two-percentage-point decrease in their likelihood of being diagnosed with dementia. Comparatively, in provinces lacking a shingles vaccination program, new dementia diagnoses were markedly more common within the same birth cohorts.

Causal Insights and Broader Implications

Dr. Geldsetzer expresses optimism in what the study reveals: “For the first time, we now have evidence that likely shows a cause-and-effect relationship between shingles vaccination and dementia prevention,” he stated. “These protective effects are significantly larger than those from current pharmacological approaches.”

Interestingly, the protective effect was observed more prominently in women than in men. “This could be linked to differences in immune response or how dementia manifests,” adds Geldsetzer. Women generally display stronger antibody responses to vaccinations, further complicating the understanding of sex-related discrepancies in dementia prevalence.

Expert Opinions and Cautions

Peter Gliebus, MD, chief neurologist at the Marcus Neuroscience Institute, approaches the study’s findings with cautious optimism. “While the results are promising, they are not definitive,” he stated. “Dementia is a complex, multi-faceted condition. Any potential intervention that could delay its onset warrants further exploration.”

Highlighting the study’s implications, Gliebus observed, “The herpes zoster vaccine may lower dementia risk by preventing reactivation of the varicella zoster virus, which has been associated with neuroinflammation. This vaccine might enhance overall neuroimmune health, reducing systemic inflammation in the process.”

Dr. David Cutler, a family medicine physician from Santa Monica, emphasized the complexities surrounding the application of the results. “It’s worth noting that Zostavax is no longer used in the United States; the newer recombinant Shingrix vaccine is in place,” he cautioned. “We cannot assume that the findings would hold across different vaccines or demographics.”

Holistic Health Strategies

While promising, the research underscores that shingles vaccination should complement a holistic approach to health, especially in aging populations. Cutler elaborates on this point: “Managing blood pressure, achieving a healthy weight, and engaging in regular exercise are also critical for cognitive function and overall aging.”

He believes the shingles vaccine could enhance an extensive list of preventative measures for cognitive decline. “It is uncertain whether the mere avoidance of shingles or direct effects of the vaccine might provide these cognitive benefits,” he added, highlighting the need for further research.

A Cultural Shift?

As media narratives continue to frame vaccination as a pivotal element of public health, societal attitudes are evolving. Maria Santos reflects on her decision, stating, “I just wanted to stay healthy, to enjoy my grandchildren and travel. If it helps with my memory, that’s a bonus!”

The potential link between the shingles vaccine and reduced dementia risk represents an exciting avenue for medical research, with implications transcending traditional vaccine narratives. As studies continue to unfold, the overarching message remains clear: simple preventative measures could hold the key to longer, healthier lives, filled with cherished memories rather than the shadows of cognitive decline.

Source: www.medicalnewstoday.com