Shingles Vaccination Went With Fewer Heart Events in Korean Adults

CATEGORY: DISEASE PREVENTION

Adults who received a shingles vaccine were less likely to develop serious heart and blood-vessel problems in the years that followed, according to a study that tracked more than a million people in South Korea. Those who were vaccinated had about a 23% lower risk of a cardiovascular event overall, and the lower risk was still visible up to eight years later.¹ Because this was an observational study, it shows an association, not proof that the vaccine itself caused the difference.

Heart Failure Risk About 26% Lower After Vaccination

Compared with unvaccinated adults, people who got the shingles vaccine had roughly 23% fewer cardiovascular events of any kind. The reductions were largest for the most serious outcomes: about 26% lower risk of a major event such as a heart attack, stroke, or death from heart disease, about 26% lower risk of heart failure (when the heart can no longer pump blood effectively), and about 22% lower risk of coronary heart disease (narrowed arteries feeding the heart). The apparent benefit was strongest in the first two to three years after vaccination but remained measurable for as long as eight years.¹

Matched Records of 1,271,922 Adults Aged 50 and Older

Researchers used national health records covering 1,271,922 adults aged 50 and older, following each person from 2012 onward for a median of about six years. They compared vaccinated and unvaccinated people who were closely matched on age, sex, wealth, and lifestyle factors, so the two groups looked as similar as possible apart from the vaccine. Heart attacks, strokes, heart failure, and related diagnoses were counted from medical records over the full follow-up period, which is what makes the long time span central to the finding rather than a snapshot in time. Cardiovascular disease identified from diagnostic codes was the study’s prespecified primary outcome.¹

Shingles Can Inflame Vessels and Encourage Clots

Shingles is caused by the reactivation of the chickenpox virus, and an active infection can inflame and injure blood vessels, encourage clots to form, and place stress on the circulation—all of which can set the stage for a heart attack or stroke. The researchers propose that by preventing shingles, the vaccine may head off some of that vascular damage. This study looked at an older, live version of the vaccine (made from a weakened virus) that many countries are now replacing with a newer non-live, recombinant shot, so it remains to be seen whether the newer vaccine shows the same pattern.

Healthier People May Simply Be More Likely Vaccinated

An observational study like this cannot rule out that healthier people were simply more likely to get vaccinated, even after the careful matching. The authors say plainly that the results do not establish that the vaccine directly protects the heart, and that the pattern in this Asian population may not carry over everywhere. Still, the sheer number of people involved and the consistency across several heart conditions make the association a notable one.¹

Newer Vaccine Linked to 43% Fewer Stroke Hospitalizations

Other research points the same way, including for the newer vaccine. In a US health system study of more than 500,000 adults aged 50 and older, those who received the newer non-live shingles vaccine 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 also observational, so it shows an association rather than cause.

Key Takeaways

• In more than a million adults aged 50 and older, shingles vaccination was linked to about a 23% lower risk of cardiovascular events, with larger reductions for heart attack, stroke, and heart failure.
• The lower risk appeared strongest in the first two to three years and was still detectable up to eight years after vaccination.
• This was an observational study, so it shows an association rather than proof of cause; it also examined an older live vaccine now being replaced by a newer recombinant one.

References

1. 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
2. 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.