The vaccine is called Shingrix, and despite being one of the most effective vaccines ever developed, nearly two-thirds of adults over 50 have not received it. Only about 36 percent of eligible adults have gotten their two doses, leaving tens of millions of people exposed not just to the agonizing pain of shingles, but potentially to dementia, heart attacks, and strokes — risks that emerging research now links to the varicella-zoster virus lurking in their nerve cells. Consider a 55-year-old woman who had chickenpox as a child and assumes shingles is something only elderly people get.
She does not realize the CDC now recommends Shingrix for everyone 50 and older, or that a Stanford study published in March 2025 found vaccinated adults were 20 percent less likely to develop dementia over the following seven years. She is part of the age group with the lowest vaccination rate — just 24 percent — and she may not know the vaccine is now free under most insurance plans. This article breaks down why so many people are skipping this vaccine, what the latest science says about its surprising benefits for brain and cardiovascular health, who qualifies, what it costs, and what the side effects actually look like in practice. If you or someone you care for is over 50 and has not had this conversation with a doctor, the research suggests it is worth having soon.
Table of Contents
- Why Are Most Adults Over 50 Still Skipping the Shingles Vaccine?
- What Does Shingles Actually Do to the Body and Brain?
- The Dementia Connection — What the Stanford Study Found
- Heart Attacks, Strokes, and Biological Aging — The Broader Health Case for Shingrix
- Who Should Not Get Shingrix — and Who Needs It Most
- Racial Disparities in Shingles Vaccination Demand Attention
- What Comes Next — The Evolving Science of Shingles and Neurodegeneration
- Conclusion
- Frequently Asked Questions
Why Are Most Adults Over 50 Still Skipping the Shingles Vaccine?
The simplest explanation is that many people do not know they are eligible. Until 2017, the CDC recommended shingles vaccination starting at age 60, not 50. When Shingrix replaced the older Zostavax vaccine and the recommended age dropped by a decade, the message did not reach everyone. Adults in their 50s — the group that arguably has the most years of protection to gain — have the lowest vaccination rate of any eligible cohort at roughly 24 percent. Cost was another major barrier until recently. Before 2023, Medicare Part D beneficiaries could face significant copays for Shingrix, and some paid the full retail price of nearly $400 for both doses out of pocket.
The Inflation Reduction Act changed that by eliminating cost-sharing for vaccines under Medicare Part D starting in January 2023, and the result was dramatic: a 46 percent increase in shingles vaccinations covered by the program, according to a study published in JAMA in May 2024. For people with private ACA-compliant insurance, the vaccine is also covered at no cost when administered in-network. Then there is the side-effect problem. Shingrix is a strong adjuvanted vaccine, and the first dose in particular can cause soreness at the injection site, fatigue, muscle pain, and headaches lasting a day or two. Some people who tolerate the first dose well enough simply never return for the second. This is a mistake. The two-dose series is what delivers the vaccine’s remarkable effectiveness — 97 percent protection against shingles for adults aged 50 to 69 — and a single dose does not provide the same durable immunity.
What Does Shingles Actually Do to the Body and Brain?
Shingles is not just a painful rash. The varicella-zoster virus, the same virus that causes chickenpox, remains dormant in nerve tissue for decades and can reactivate when the immune system weakens with age, stress, or illness. When it does, it causes a blistering rash that typically wraps around one side of the torso or face, accompanied by burning, stabbing nerve pain. About one in three Americans will develop shingles in their lifetime, and the risk increases sharply after 50. The complication that keeps pain specialists up at night is postherpetic neuralgia, a condition where the nerve pain persists for months or even years after the rash has healed. It affects roughly 10 to 18 percent of shingles patients and is more common in older adults.
The pain can be severe enough to interfere with sleep, daily activities, and mental health. However, if the virus reactivates near the eye — a condition called herpes zoster ophthalmicus — it can cause permanent vision loss. These are not rare edge cases. They are well-documented complications that the vaccine was specifically designed to prevent. What has caught the attention of researchers in neurology and dementia care, though, is growing evidence that varicella-zoster reactivation may contribute to neurodegeneration. The virus can trigger inflammation in blood vessels and nerve tissue, and this inflammatory cascade appears to have downstream effects on the brain. This is where the vaccine story becomes about far more than avoiding a rash.
The Dementia Connection — What the Stanford Study Found
In March 2025, researchers at Stanford Medicine published findings showing that adults who received the shingles vaccine were 20 percent less likely to develop dementia over the next seven years compared to unvaccinated adults. This was not a small or speculative study. It drew on large-scale health records and controlled for the kinds of confounding variables — age, overall health, socioeconomic status — that can muddy observational research. The most striking finding was the reduction in vascular dementia specifically, with vaccinated adults showing a 50 percent lower risk. Vascular dementia is the second most common form of dementia after Alzheimer’s disease and is driven by impaired blood flow to the brain, often from small strokes or chronic vascular inflammation.
The connection makes biological sense: varicella-zoster virus has been shown to infect blood vessel walls and trigger inflammation that can contribute to clot formation and vessel damage. By preventing viral reactivation, the vaccine may be interrupting one of the pathways that leads to this type of cognitive decline. For families already navigating dementia care, this research raises an uncomfortable question: could a widely available vaccine have reduced someone’s risk, and was the opportunity missed? It is important to note that this research does not prove the vaccine prevents dementia — no randomized controlled trial has tested that specific hypothesis yet. But the association is strong enough that neurologists and geriatricians have begun incorporating the conversation into routine cognitive health discussions. For adults over 50 who have not yet developed dementia, vaccination may be one of the more actionable steps available, alongside blood pressure management, exercise, and hearing correction.
Heart Attacks, Strokes, and Biological Aging — The Broader Health Case for Shingrix
The benefits extend beyond the brain. Research published by the Infectious Diseases Society of America found that shingles-vaccinated adults had a 27 percent lower risk of blood clots, a 25 percent lower risk of heart attack or stroke, and a 21 percent lower risk of death from any cause. These are large effect sizes for a single intervention, and they suggest that the chronic low-grade inflammation caused by latent varicella-zoster virus may be doing more systemic damage than previously understood. A February 2026 study added another dimension, finding evidence that the shingles vaccine may slow biological aging and reduce markers of chronic inflammation. Biological age — measured through epigenetic clocks and inflammatory biomarkers — can diverge significantly from chronological age, and interventions that slow biological aging are of intense interest to longevity researchers.
The shingles vaccine was not designed with this goal in mind, but the data suggest it may be achieving it as a secondary effect. The tradeoff worth acknowledging is that these cardiovascular and aging benefits are still emerging from observational data, not randomized trials. It is possible that people who get vaccinated are also more likely to engage in other health-promoting behaviors, and that some of the observed benefit reflects this “healthy user” effect rather than the vaccine itself. Researchers have attempted to control for this, but no observational study can eliminate it entirely. Still, the consistency of findings across multiple independent studies, populations, and health outcomes makes a compelling case that something real is happening beyond simple prevention of a rash.
Who Should Not Get Shingrix — and Who Needs It Most
Shingrix is recommended for all immunocompetent adults aged 50 and older, including those who have already had shingles, those who received the older Zostavax vaccine, and those who are not sure whether they ever had chickenpox. The CDC also recommends it for adults 19 and older whose immune systems are compromised by disease or medical treatment, including people undergoing chemotherapy, organ transplant recipients on immunosuppressive drugs, and those living with HIV. However, there are situations where the vaccine should be delayed or avoided. People who are currently experiencing a shingles outbreak should wait until the rash has fully resolved. Those who have had a severe allergic reaction to any component of Shingrix should not receive it. Pregnant individuals should defer vaccination.
And people with moderate to severe acute illness — not a minor cold, but something requiring medical attention — are generally advised to wait until they recover before getting vaccinated. One warning that deserves more attention: the gap between doses matters. The CDC recommends the second dose two to six months after the first. Some people delay the second dose well beyond this window, either because they forgot, because side effects from the first dose were unpleasant, or because of scheduling difficulties. While a delayed second dose is still better than no second dose, the immune response is optimized within the recommended timeframe. If you or a family member received only one dose of Shingrix months or years ago, it is worth calling your doctor’s office rather than assuming the window has closed — you do not need to restart the series.
Racial Disparities in Shingles Vaccination Demand Attention
The overall vaccination rate of 36 percent is troubling, but the racial breakdown is worse. Among adults 60 and older, White adults have a vaccination rate of about 38.6 percent, while Black adults reach only 18.8 percent and Hispanic adults 19.5 percent — roughly half the rate. These gaps are not explained by differences in shingles risk.
They reflect longstanding disparities in healthcare access, provider recommendation patterns, pharmacy availability in underserved communities, and trust. For dementia caregivers in Black and Hispanic communities, where Alzheimer’s and vascular dementia rates are already disproportionately high, these vaccination gaps carry a double burden. If the shingles vaccine truly reduces dementia risk by 20 percent and cuts vascular dementia risk in half, then communities with the lowest vaccination rates are also missing out on one of the few available interventions that might reduce their elevated dementia burden. Community health centers, faith-based health programs, and culturally competent outreach campaigns have shown promise in narrowing these gaps for other vaccines, and similar approaches are needed for Shingrix.
What Comes Next — The Evolving Science of Shingles and Neurodegeneration
The next several years are likely to bring clearer answers about the relationship between viral infections and dementia. Researchers are investigating whether other common viruses — herpes simplex, Epstein-Barr, cytomegalovirus — may contribute to neurodegeneration through similar inflammatory mechanisms. If the pattern holds, we may be entering an era where vaccination becomes a recognized pillar of dementia prevention, alongside the lifestyle interventions and amyloid-targeting therapies that currently dominate the conversation. For now, the practical takeaway is straightforward.
Shingrix is 97 percent effective at preventing shingles in adults 50 to 69 and 91 percent effective in adults over 70, with protection lasting at least seven to ten years. It is free under Medicare Part D and most private insurance plans. And the emerging evidence linking it to reduced risks of dementia, cardiovascular events, and even biological aging makes the case for vaccination stronger than it has ever been. The science will continue to evolve, but waiting for perfect certainty while a well-studied, highly effective, and now cost-free vaccine sits on pharmacy shelves is a gamble that the data increasingly argues against.
Conclusion
The shingles vaccine is one of the most effective and underused tools in preventive medicine for adults over 50. With only 36 percent of eligible adults vaccinated, and rates dropping below 25 percent for those in their 50s and below 20 percent in Black and Hispanic communities, millions of people are missing out on protection that goes far beyond preventing a painful rash. The emerging links between Shingrix and reduced risks of dementia, heart attack, stroke, blood clots, and even accelerated aging have transformed what was once a straightforward pain-prevention vaccine into something that looks increasingly like a cornerstone of healthy aging. If you are caring for someone with dementia or cognitive decline, or if you are over 50 yourself, bring this up at the next medical appointment.
Ask specifically about Shingrix, confirm insurance coverage, and schedule both doses within the recommended two-to-six-month window. For those on Medicare Part D, the vaccine has been free since 2023. For those with private insurance, in-network administration should carry no cost-sharing. The side effects are real but temporary — a sore arm and a tired day are a small trade for years of protection against shingles, its complications, and potentially against cognitive and cardiovascular decline.
Frequently Asked Questions
Do I need the shingles vaccine if I have already had shingles?
Yes. The CDC recommends Shingrix for adults 50 and older regardless of whether they have had shingles before. The virus remains in your nerve tissue and can reactivate more than once. Vaccination after an episode reduces the risk of recurrence.
I got the old Zostavax vaccine years ago. Do I still need Shingrix?
Yes. Zostavax, a live vaccine that was discontinued in the United States in 2020, provided weaker and shorter-lasting protection. The CDC recommends that anyone who received Zostavax get the two-dose Shingrix series for stronger, more durable immunity.
Is the shingles vaccine really free now?
For Medicare Part D enrollees, yes — the Inflation Reduction Act eliminated out-of-pocket costs for all Part D-covered vaccines starting in January 2023. For adults with ACA-compliant private insurance, Shingrix is covered with no cost-sharing when given by an in-network provider. Without insurance, the retail price is approximately $395.80 for both doses.
Can the shingles vaccine actually prevent dementia?
A large Stanford study published in March 2025 found a 20 percent lower risk of dementia and a 50 percent lower risk of vascular dementia among vaccinated adults over seven years of follow-up. These are observational findings, not proof of causation, but the association is strong and biologically plausible. Randomized trials have not yet been conducted to confirm this specific benefit.
What are the side effects of Shingrix?
The most common side effects are pain and swelling at the injection site, fatigue, muscle aches, and headaches, typically lasting one to three days. These are signs of a strong immune response, not illness. Serious side effects are rare. Some people find the first dose produces more noticeable side effects, which can deter them from returning for the second dose — but completing the series is essential for full protection.
I am under 50 but have a weakened immune system. Can I get Shingrix?
Yes. The CDC recommends Shingrix for adults 19 and older who are immunocompromised, including those on immunosuppressive therapy, chemotherapy, or living with conditions like HIV that weaken the immune system. Talk to your doctor about the timing relative to any treatments you are receiving.
