Heart Patients Given This Vaccine Were 66% Less Likely to Die

The shingles vaccine may do more than prevent shingles. A large new study EurekAlert finds that people with heart disease who got vaccinated had nearly half the rate of serious cardiac events within a year, compared with those who did not.

The study, which will be presented at the American College of Cardiology Annual Scientific Session (ACC.26) in New Orleans at the end of March, analyzed health records for more than 246,000 U.S. adults with atherosclerotic heart disease between 2018 and 2025. Using the TriNetX database, researchers matched 123,411 people who had received at least one dose of the shingles vaccine — Shingrix or Zostavax — with an equal number who had not been vaccinated, then tracked outcomes between one month and one year later.

The vaccinated group showed lower risk across every measure studied. They were 46% less likely to suffer a major adverse cardiac event — heart attack, stroke, or cardiovascular death — 66% less likely to die from any cause, 32% less likely to have a heart attack, 25% less likely to have a stroke, and 25% less likely to develop heart failure.

Those numbers are large. Dr. Robert Nguyen, a resident physician at the University of California, Riverside, and the study lead author, said the reductions are comparable to what you would expect from quitting smoking. He framed the findings as the latest in a series of consistent signals: the vaccine keeps showing up as protective against heart events, and the effect appears stronger in higher-risk populations.

The biology connecting shingles to cardiovascular risk has a plausible mechanism. The varicella-zoster virus, which causes both chickenpox and shingles, can trigger blood clot formation near the brain and heart when it reactivates. Preventing the infection with a vaccine avoids that inflammatory and thrombotic cascade. Nguyen noted that a prior study, published in 2025, found a 23% reduction in cardiovascular events among generally healthy adults vaccinated against shingles, with benefits lasting up to eight years. That prior work, by Lee et al. in the European Heart Journal, analyzed 1.27 million participants.

This study adds the piece that was missing: a large, matched cohort of people who already had established cardiovascular disease. That is the group where the risk reduction appears most dramatic — which makes intuitive sense, since people with existing disease have more to gain from avoiding an additional insult.

One caveat: the study only tracks outcomes during the first year after vaccination. Researchers adjusted for demographics, health conditions, and some socioeconomic factors, but people who choose to get vaccinated may also have healthier behaviors in ways that are hard to fully account for. The study will be presented as a poster at ACC.26 on March 30 — it has not yet been published in a peer-reviewed journal, which means the full dataset has not undergone independent scrutiny.

The CDC already recommends the shingles vaccine for adults 50 and older and for younger adults with weakened immune systems. These data support that recommendation and may expand the calculus around who should get vaccinated — not just to avoid a painful rash and nerve pain, but because the cardiovascular protection appears real and clinically meaningful.

If the findings hold up to peer review, the public health implication is significant: an existing, widely-used vaccine with a well-understood safety profile might be a cardiovascular intervention hiding in plain sight.