These compelling findings, emerging from research presented at the American College of Cardiology’s Annual Scientific Session (ACC.26), underscore a potentially transformative role for the shingles vaccine beyond its primary function of preventing herpes zoster. The study, which meticulously analyzed data from a vast cohort of over 246,822 adults across the United States already diagnosed with atherosclerotic heart disease, suggests that the protective effects of the vaccine extend significantly to cardiovascular health, particularly in a population already at elevated risk. A Significant Reduction in Cardiovascular Risk The research revealed a profound reduction in major adverse cardiac events (MACE) among vaccinated individuals. Specifically, those who received at least one dose of the shingles vaccine (either Shingrix or Zostavax) were 46% less likely to experience a MACE within a year of vaccination compared to their unvaccinated counterparts. This category encompasses severe outcomes such as heart attacks, strokes, and death. Delving deeper into specific cardiovascular events, the study reported a 32% reduction in the risk of heart attack, a 25% reduction in the risk of stroke, and a 25% reduction in the risk of heart failure. Perhaps most strikingly, the vaccinated group exhibited a 66% lower likelihood of all-cause mortality during the observed timeframe. These statistics represent a substantial protective effect, comparable to the benefits derived from major lifestyle interventions such as quitting smoking, as noted by the study’s lead author, Robert Nguyen, MD, a resident physician at the University of California, Riverside. "This vaccine has been found over and over again to have cardioprotective effects for reducing heart attack, stroke and death," Dr. Nguyen stated. "Looking at the highest risk population, those with existing cardiovascular disease, these protective effects might be even greater than among the general public." This observation highlights the particular relevance of these findings for patients already navigating the complexities of heart disease, for whom every reduction in risk can significantly impact their quality of life and longevity. Understanding Atherosclerotic Heart Disease Atherosclerotic heart disease, the focus of this study, is a chronic and progressive condition caused by the buildup of plaque within the arteries. This plaque, composed of cholesterol, fatty substances, cellular waste products, calcium, and fibrin, hardens and narrows the arteries, restricting blood flow to vital organs like the heart and brain. It is the underlying cause of conditions such as coronary artery disease, peripheral artery disease, and cerebrovascular disease, leading to heart attacks, strokes, and other serious cardiovascular events. Individuals with this diagnosis are inherently at a higher baseline risk for future cardiac incidents, making any preventative measure particularly valuable. The Shingles Vaccine: A Dual-Purpose Preventative Tool The Centers for Disease Control and Prevention (CDC) currently recommends the shingles vaccine for adults age 50 years and older, as well as younger individuals with weakened immune systems. The vaccine targets the varicella-zoster virus, which is responsible for chickenpox during its initial infection. Years, or even decades, after the initial chickenpox infection, the virus can reactivate, causing shingles (herpes zoster) – a painful rash often accompanied by severe, long-lasting nerve pain known as postherpetic neuralgia. The emerging evidence suggests that the vaccine’s benefits extend beyond merely preventing this painful rash. Earlier research has established a crucial link between acute shingles infections and an increased risk of cardiovascular events. The inflammatory response triggered by the reactivated virus can lead to systemic inflammation, endothelial dysfunction (damage to the lining of blood vessels), and hypercoagulability (an increased tendency for blood to clot). This inflammatory cascade can promote the formation of blood clots near the brain and heart, elevating the risk of heart attacks, strokes, and venous thromboembolism. By preventing the shingles infection itself, the vaccine effectively preempts this inflammatory surge, thereby mitigating the associated cardiovascular risks. Rigorous Methodology and Robust Data To conduct this large-scale analysis, researchers leveraged TriNetX, an extensive federated research network that aggregates de-identified medical records from millions of Americans across various healthcare organizations. The study cohort comprised adults aged 50 years or older diagnosed with atherosclerotic disease between 2018 and 2025. The analysis involved two meticulously matched groups, each containing 123,411 individuals. One group consisted of patients who had received at least one dose of either the Shingrix or Zostavax vaccine. The control group consisted of an equal number of unvaccinated individuals. Crucially, both groups were carefully balanced across a wide array of demographic factors, including age, sex, race, ethnicity, and socioeconomic status. Furthermore, researchers adjusted for numerous underlying health conditions and comorbidities, such as diabetes, hypertension, hyperlipidemia, chronic kidney disease, and history of smoking, ensuring that the comparison was as robust as possible. This meticulous matching process helps to minimize confounding variables and strengthen the validity of the observed associations. The researchers focused on heart-related outcomes that occurred between one month and one year after the date of vaccination for the vaccinated group, and within the equivalent timeframe for the unvaccinated control group. This specific window allowed for the observation of both acute and short-to-medium-term protective effects. A Growing Body of Evidence and Broader Implications These findings add significant weight to a burgeoning body of research indicating that the shingles vaccine may offer broader health benefits beyond its primary indication. While the current study focused on individuals with existing heart disease, a previous study published in 2025 indicated that shingles vaccination was linked to a 23% reduction in cardiovascular events in generally healthy adults, with benefits that could potentially last up to eight years. The current research, therefore, suggests that these cardioprotective effects are not only real but potentially amplified in populations already compromised by cardiovascular disease. The implications for public health and clinical practice are substantial. For physicians, particularly cardiologists and primary care providers, these results provide a compelling additional reason to recommend the shingles vaccine to their eligible patients, especially those with diagnosed atherosclerotic heart disease. The conversation around vaccination can now extend beyond preventing a painful rash to actively safeguarding cardiovascular health. From a public health perspective, the findings reinforce the critical role of vaccination in preventing disease and reducing healthcare burdens. In an era where vaccine hesitancy and misinformation pose significant challenges, studies like this offer concrete, data-driven evidence of vaccine efficacy and wide-ranging health advantages. "Vaccines are one of the most important medicines we have to prevent disease," Dr. Nguyen emphasized. "Sometimes patients are unsure about whether they should get a vaccine or not, particularly in an age of disinformation. These results provide another reason for them to elect to get the vaccine." Limitations and Future Directions While the study presents robust evidence, it is important to acknowledge certain limitations inherent in observational research. The analysis primarily tracked outcomes during the first year after vaccination, meaning the long-term effects beyond this period require further investigation. Although previous research suggests longer-lasting benefits, specific data for patients with pre-existing heart disease beyond one year would be valuable. One common challenge in observational studies is the potential for "healthy user bias." It is plausible that individuals who choose to get vaccinated may also be more health-conscious overall, engaging in other healthier behaviors, such as adhering to medication, maintaining a balanced diet, or exercising regularly. While the researchers made considerable efforts to adjust for a wide range of health and socioeconomic factors (including problems related to housing and economic circumstances, social environment, employment status, education, and literacy), it is still possible that some unmeasured confounding factors could influence the observed benefits. Despite these limitations, the study’s exceptionally large sample size, meticulous matching, and rigorous statistical approach provide strong evidence of a meaningful association between shingles vaccination and a significant reduction in cardiovascular risk. Future research could include randomized controlled trials, if ethically feasible, to further establish causality. Additionally, studies exploring the precise biological mechanisms through which the vaccine confers cardioprotection, as well as analyses across more diverse populations and longer follow-up periods, would further enrich our understanding. The presentation of the study, titled "Herpes Zoster Vaccination and Risk of Cardiovascular Events in Patients with Atherosclerotic Cardiovascular Disease," is scheduled for Monday, March 30, at 12:30 p.m. CT / 17:30 UTC in Posters, Hall E, at the American College of Cardiology’s Annual Scientific Session. This pivotal research adds a powerful new dimension to the understanding of vaccine benefits, positioning the shingles vaccine not just as a defense against a painful viral infection, but as a critical tool in the ongoing battle against cardiovascular disease, especially for those most vulnerable. Post navigation A lost disease emerges from 5,500-year-old human remains
