The shingles vaccine may deliver far more than protection against a painful rash – new research suggests it could actually slow down the aging process itself. A groundbreaking study from the University of Southern California Leonard Davis School of Gerontology, published in the Journals of Gerontology, reveals that adults aged 70 and older who received the shingles vaccine showed measurably slower biological aging compared to their unvaccinated peers, even when accounting for numerous health and demographic factors.
Understanding Biological Age vs. Calendar Age
Most people think of aging in simple terms – how many birthdays they’ve celebrated. But scientists increasingly recognize that chronological age tells only part of the story. Biological age measures how well your body actually functions: the health of your organs, the integrity of your DNA, the effectiveness of your immune system, and the level of inflammation coursing through your tissues.
Two 70-year-olds might look dramatically different on the inside. One could possess the cardiovascular system, cognitive function, and cellular health of someone a decade younger, while another might show signs of accelerated wear and tear. These differences in biological aging predict everything from disease risk to lifespan far more accurately than the number on your driver’s license.
Research Associate Professor Jung Ki Kim and AARP Professor of Gerontology Eileen Crimmins analyzed data from more than 3,800 participants in the nationally representative U.S. Health and Retirement Study. All participants were aged 70 or older in 2016, when researchers collected comprehensive biological measurements from venous blood samples, flow cytometry analyses, DNA methylation studies, gene expression profiling, and standardized physical assessments.
The team examined seven distinct domains of biological aging: inflammation levels, innate immunity (the body’s general defenses), adaptive immunity (responses to specific pathogens), cardiovascular function, neurodegeneration markers, epigenetic aging (changes in how genes are expressed), and transcriptomic aging (alterations in gene activity). They also calculated a composite biological aging score integrating these multiple dimensions.
The Inflammaging Connection: A Key to Understanding
The study’s most striking findings centered on inflammation, specifically, a phenomenon scientists call “inflammaging.” This refers to the chronic, low-grade inflammation that gradually increases with age and contributes to virtually every age-related disease, from cardiovascular conditions and diabetes to cognitive decline and frailty.
According to the research published in the Journals of Gerontology, vaccinated individuals demonstrated significantly lower inflammation scores compared to unvaccinated participants. This reduction wasn’t trivial – inflammation measurements showed substantial improvements that persisted even after controlling for socioeconomic status, education levels, smoking history, existing chronic conditions, and influenza vaccination patterns.
Professor Kim explained that the vaccine may impact biological aging by preventing reactivation of the varicella-zoster virus that causes shingles. Anyone who has had chickenpox, which includes approximately 95 percent of Americans over age 40-carries this virus dormant in their nerve cells for life. When the immune system weakens with age or stress, the virus can reactivate, causing not just the characteristic painful rash but also triggering widespread inflammatory responses throughout the nervous system.
By keeping the virus suppressed, the shingles vaccine may reduce this constant inflammatory burden. Over years and decades, this reduction in background inflammation could translate into meaningful differences in how organs age, how tissues repair themselves, and how the immune system maintains its vigilance against other threats.
Molecular Clocks Show Slower Ticking
Beyond inflammation, the USC researchers discovered that vaccinated participants exhibited slower epigenetic and transcriptomic aging, two sophisticated measures of how our cells change over time at the molecular level. Epigenetic changes involve chemical modifications to DNA that alter which genes are turned on or off without changing the underlying genetic code itself. Scientists have developed “epigenetic clocks” that can predict biological age with remarkable accuracy by examining these patterns.
Transcriptomic aging refers to changes in gene expression, which genes are actively producing proteins and in what quantities. As we age, these patterns shift in predictable ways that contribute to declining cellular function. The study found that shingles vaccination correlated with slower rates of change in both these fundamental aging processes.
Perhaps most remarkably, these benefits appeared to persist over time. When researchers analyzed how long ago participants had received their vaccines, they found that even those vaccinated four or more years prior to blood collection still showed slower epigenetic, transcriptomic, and overall biological aging compared to unvaccinated individuals. This suggests the vaccine’s effects on aging aren’t merely temporary responses to recent immunization but may represent lasting changes in how the body manages inflammation and maintains cellular health.
The timing analysis revealed interesting nuances. The anti-aging signals appeared strongest within three years of vaccination for molecular markers like epigenetic and transcriptomic aging, while inflammation benefits emerged more prominently after four or more years. This temporal pattern suggests complex, multi-stage mechanisms through which the vaccine influences aging biology.
Beyond Shingles: Vaccines as Longevity Interventions
The USC findings align with an emerging body of research suggesting that adult vaccinations may offer health benefits extending far beyond their primary disease-prevention targets. Recent studies have documented associations between shingles vaccination and reduced risks of several age-related conditions.
Research presented at IDWeek 2025 analyzed health records from over 174,000 adults across 107 U.S. health systems and found that shingles vaccination correlated with dramatically lower risks: 50 percent reduction in vascular dementia, 27 percent decrease in blood clots, 25 percent lower incidence of heart attack or stroke, and 21 percent reduction in all-cause mortality. These findings, though not yet published in peer-reviewed journals, suggest the vaccine’s impact extends throughout the cardiovascular and neurological systems.
According to research from Stanford Medicine published in Nature and Cell, the shingles vaccine may not only prevent or delay dementia diagnoses but also slow disease progression in those already experiencing cognitive decline. A study examining Welsh health records found that among people living with dementia, those who received the shingles vaccine showed a 29.5 percentage point reduction in deaths attributed to dementia over nine years compared to unvaccinated individuals.
These diverse benefits likely share common mechanisms. Chronic viral reactivation and the inflammation it triggers affect multiple organ systems simultaneously. By dampening this inflammatory burden, the vaccine may provide system-wide protective effects that manifest differently depending on individual vulnerabilities and genetic predispositions.
Zostavax vs. Shingrix: Questions for Future Research
An important caveat concerns which vaccine was studied. The USC research examined Zostavax, the older single-dose live-attenuated shingles vaccine recommended for people 60 and older. In 2017, it was largely replaced by Shingrix, a newer two-dose recombinant vaccine that demonstrates significantly higher effectiveness, over 90 percent protection against shingles compared to Zostavax’s 51 to 70 percent efficacy.
Whether Shingrix produces similar or even enhanced anti-aging effects remains unknown. The newer vaccine triggers a more robust immune response, which could theoretically amplify beneficial effects on inflammation and biological aging. Alternatively, different mechanisms of action between the two vaccines, live-attenuated versus recombinant protein might produce distinct biological consequences.
Professor Crimmins emphasized that while the findings are compelling, further research using longitudinal designs and randomized controlled trials will be necessary to definitively establish causation. The current study’s cross-sectional design cannot completely rule out the possibility that healthier people with lower baseline inflammation simply prove more likely to seek vaccination, even after accounting for measured confounders.
Practical Implications for Healthy Aging
Despite these methodological limitations, the consistency and magnitude of the associations, combined with supporting evidence from multiple independent studies, suggest real biological effects worth taking seriously. For individuals considering whether to get vaccinated, the potential anti-aging benefits represent a significant additional incentive beyond shingles prevention alone.
The Centers for Disease Control and Prevention recommends that adults aged 50 and older receive two doses of Shingrix vaccine, spaced two to six months apart. The vaccine is covered by Medicare Part D and most private insurance plans, though out-of-pocket costs can reach several hundred dollars for uninsured individuals.
Shingles itself represents far more than a temporary inconvenience. The painful rash can last weeks and, in approximately 10 to 18 percent of cases, leads to postherpetic neuralgia, chronic nerve pain persisting months or years after the rash heals. Older adults face higher risks not only of developing shingles but also of experiencing these debilitating long-term complications.
Given that anyone who has had chickenpox remains at risk for shingles, and that risk increases substantially after age 50, vaccination offers multiple layers of protection: preventing acute illness, reducing chronic pain complications, and potentially, as the new research suggests, slowing fundamental aging processes that drive age-related disease across multiple organ systems.
The Bigger Picture: Vaccines and Healthy Aging
The USC study contributes to a paradigm shift in how we think about adult immunization. For decades, vaccines were viewed primarily as tools for preventing acute infectious disease. The emerging evidence suggests they may represent powerful interventions in the aging process itself, modulating immune function, reducing chronic inflammation, and potentially extending not just lifespan but healthspan: the years lived free from disability and chronic disease.
Professor Kim noted that vaccines could play a role in promoting healthy aging by modulating biological systems beyond infection prevention. This perspective opens new research directions exploring whether other common adult vaccines, influenza, pneumococcal, COVID-19 – might offer similar anti-aging benefits through related mechanisms.
The concept isn’t entirely surprising when viewed through the lens of inflammaging. Vaccines work by training the immune system, and a well-trained immune system responds more appropriately to threats, mounting robust responses when needed while avoiding the excessive, chronic activation that drives inflammatory aging. By preventing specific viral reactivations and infections, vaccines reduce the inflammatory burden that accelerates aging across multiple biological systems.
As global populations continue aging, with projections suggesting 1.5 billion people over age 65 by 2050, identifying interventions that promote healthy aging becomes increasingly urgent. If widely accessible vaccines can meaningfully slow biological aging while preventing painful diseases, they represent extraordinarily cost-effective public health tools with potential to reduce both individual suffering and societal healthcare burdens.
The convergence of evidence from multiple studies across different populations and research designs suggests we may be witnessing the early recognition of vaccines’ role as longevity interventions, a role that could transform how we approach preventive medicine for aging populations worldwide.
Primary Study Citation: Jung Ki Kim, Eileen M. Crimmins, “Association between shingles vaccination and slower biological aging: Evidence from a U.S. population-based cohort study,” The Journals of Gerontology: Series A (2026). DOI: 10.1093/gerona/glag008
