CATEGORY: DISEASE PREVENTION
Adults who received a shingles vaccine had about a 23% lower risk of a serious heart or blood-vessel event in the years that followed, in a study tracking more than a million people in South Korea. The lower risk was still visible eight years out.1 Nobody handed out the vaccine for research purposes; investigators watched who happened to receive it. That makes the finding an association, not proof the vaccine caused the difference.
The Biggest Gaps Showed Up in the Worst Outcomes
Vaccinated adults had roughly 23% fewer cardiovascular events of any kind than unvaccinated ones. The gaps widened for the most serious outcomes: about 26% lower risk of a major event, meaning a heart attack, a stroke or a death caused by heart disease; about 26% lower risk of heart failure; and coronary heart disease about 22% lower. Heart failure is when the heart can no longer pump blood effectively. Coronary heart disease is narrowing of the arteries feeding the heart. The apparent benefit peaked in the first two to three years after vaccination and stayed measurable for as long as eight years.1
1,271,922 Records, Matched Pair by Pair
National health records covering 1,271,922 adults aged 50 and older supplied the data, with follow-up running from 2012 onward for a median of roughly six years. Vaccinated and unvaccinated people were closely matched on age, sex, wealth and lifestyle factors, so the two groups looked as alike as possible apart from the shot itself. Heart attacks, strokes, heart failure and related diagnoses were counted from medical records across the entire follow-up window. The length of that window is what makes the finding more than a snapshot in time. Cardiovascular disease identified from diagnostic codes was the study’s prespecified primary outcome.1
A Virus That Inflames Blood Vessels
Shingles comes from the chickenpox virus reactivating. An active infection can inflame and injure blood vessels, encourage clots to form, and put stress on the circulation, all of which can set the stage for a heart attack or stroke. Preventing shingles, the researchers propose, may head off some of that vascular damage. One caveat sits in the vaccine itself. This study looked at an older, live version made from a weakened virus, and many countries are now replacing it with a newer non-live recombinant shot.
Healthier People May Simply Be Likelier to Get Vaccinated
Careful matching cannot rule that out. The authors say plainly that their results do not establish that the vaccine protects the heart directly, and that a pattern found in this Asian population may not carry everywhere. The sheer number of people involved and the consistency across several heart conditions still make the association a notable one.1 Research on the newer vaccine points the same way. Among more than 500,000 adults aged 50 and older in an American health system, those who received the non-live shot had about a 28% lower risk of being hospitalized for a heart attack and about a 43% lower risk of hospitalization for stroke.2 That study was observational too.
Key Takeaways
- Shingles vaccination tracked with about 23% lower risk of cardiovascular events across more than a million adults aged 50 and older, with larger gaps for heart attack, stroke and heart failure.
- The association was strongest in the first two to three years and still detectable eight years on.
- This is observational evidence rather than proof of cause, and the vaccine studied was an older live one now being replaced by a recombinant version.
References
- Lee S, Lee K, Oh J, et al. Live zoster vaccination and cardiovascular outcomes: a nationwide, South Korean study. European Heart Journal. 2025;46(30):2991–3002. link
- Rayens E, Sy LS, Qian L, et al. Adjuvanted recombinant zoster vaccine is effective against herpes zoster ophthalmicus, and is associated with lower risk of acute myocardial infarction and stroke in adults aged ≥50 years. Clinical Infectious Diseases. 2025;81(5):e441–e445. link.