A new study suggests the shingles vaccine may offer significant heart protection in addition to preventing its signature painful rash. Researchers in South Korea analyzed over a decade of health records from more than 1.2 million people aged 50 and older.

They discovered that vaccinated individuals had a 23% lower risk of developing major heart problems. This included a reduced likelihood of stroke, heart failure, and coronary artery disease, with the protective benefits lasting for up to eight years.

The positive effect on heart health was not uniform across all groups. People under 60 saw the greatest benefit, likely due to a stronger immune response, and the effect was also more pronounced in men and those with unhealthy lifestyle habits.

Shingles is caused by the reactivation of the chickenpox virus. Because the infection itself can lead to blood vessel damage and inflammation, researchers hypothesized that preventing it with a vaccine would also lower the associated cardiac risks.

The study’s lead author noted that the vaccine appears to help reduce heart disease risk even in people without known factors. This suggests the shot’s benefits extend beyond its primary purpose of preventing the shingles virus.

However, the study has limitations. It used a live vaccine, whereas the U.S. primarily uses Shingrix, a more effective non-live version. Furthermore, the research was conducted on a single ethnic group in Asia.

Experts say that while the findings are promising, further studies including a more diverse population are needed. This would help confirm whether the significant heart-protective benefits apply to all ethnic groups.