Wales – January 26, 2024 — Could a simple shingles vaccine be a surprising ally in the fight against dementia? New research suggests a link between shingles vaccination and a reduced risk of cognitive decline, offering a potential new avenue for prevention and treatment.
Shingles Vaccine Linked to Lower Dementia Risk in New Study
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A study of over 300,000 people in Wales found those vaccinated against shingles had a lower incidence of mild cognitive impairment and dementia-related deaths.
- Research indicates shingles vaccination may reduce the risk of dementia by as much as 20 percent.
- The protective effect appears stronger in women than in men.
- A newer shingles vaccine, Shingrix, shows even greater potential benefits.
- The findings highlight the potential for vaccination to play a role in brain health.
The findings, published in the journal Cell, analyzed health records from more than 300,000 individuals in Wales between 2013 and 2022. Researchers from Stanford University, the Heidelberg Institute of Global Health, and Cardiff University discovered that people eligible for the live shingles vaccine (Zostavax) were less likely to develop mild cognitive impairment—an early indicator of dementia. Furthermore, those already diagnosed with dementia experienced a lower risk of death from the disease.
Could getting a shingles shot actually protect your brain? Researchers believe the shingles vaccine could potentially prevent early memory decline and slow disease progression. Because the vaccine is safe, affordable, and widely available, these findings could have significant public health implications, though further research is needed to confirm the benefits and understand the underlying mechanisms.
How the Study Worked
Researchers utilized the UK National Health Service’s phased rollout of the shingles vaccination program as a “natural experiment.” Eligibility for the vaccine was determined by date of birth, allowing for a comparison between two similar groups: those born just before and after the eligibility cutoff. This approach helped isolate the effect of the vaccine itself.
The study builds on previous work by the same research team, which initially suggested a possible link between shingles vaccination and dementia prevention. More recently, a 2024 study in Nature linked the newer Shingrix vaccine to an even more pronounced protective effect. After six years, adults over 65 who received Shingrix had a 17 percent lower risk of dementia compared to those who received Zostavax. This protective effect was even stronger in women, at 22 percent, compared to 13 percent in men.
Overall, individuals who received Shingrix demonstrated a 23 to 27 percent lower risk of developing dementia compared to those who received other common vaccines like those for flu, tetanus, diphtheria, or pertussis. While the exact mechanism isn’t fully understood, researchers theorize the vaccine may prevent the reactivation of dormant viruses—such as varicella zoster (the virus that causes shingles) and herpes simplex—which are thought to contribute to brain inflammation and the buildup of proteins associated with dementia. Another possibility is that the vaccine provides a general boost to the immune system, counteracting the age-related decline in immune function.
Ireland’s Shingles Vaccination Landscape
In July 2024, the Health Information Quality Authority (HIQA) in Ireland published a Health Technology Assessment (HTA) evaluating shingles vaccination for adults. The assessment, requested by the Department of Health following a recommendation from the National Immunisation Advisory Committee (NIAC), aimed to advise the Minister for Health on the potential inclusion of shingles vaccination in the country’s adult immunization program.
HIQA’s Chief Scientist, Dr. Conor Teljeur, stated that the HTA, which included public consultation, considered the burden of shingles disease, patient experiences, and social impacts. “Our assessment concludes that the shingles vaccine is safe and effective, but that the benefit of the vaccine decreases over time,” Dr. Teljeur said. “We found that, at the current vaccine price, adding shingles vaccination to the routine immunisation schedule for the general population aged 50 years and older would not be an efficient use of HSE resources.”
Public feedback highlighted the significant impact shingles can have on individuals, particularly those experiencing long-term complications. Currently, shingles vaccines are available in Ireland, but individuals must pay out-of-pocket. A two-dose course of Shingrix typically costs between €480 and €490 (approximately €240–€245 per dose), covering the vaccine, consultation, and administration.
The incidence and severity of shingles increase with age, with most cases occurring in people over 50. Individuals with compromised immune systems are also at higher risk of developing shingles and experiencing a more severe illness. HIQA’s assessment considered the impact of providing shingles vaccination to adults aged 50 and older, as well as those 18 and older with weakened immune systems.
Currently, this relatively expensive vaccine is not included in Ireland’s adult immunization schedule. However, the emerging evidence regarding the potential links between shingles vaccination and dementia protection or slowed progression may prompt a reevaluation of this advice in the future.
For now, the health benefits of shingles vaccines may extend far beyond protection against the painful rash itself.
