Last updated on May 22nd, 2025 at 01:15 pm

A new study from South Korea shows that the shingles vaccine reduces various cardiovascular events by 23%. Thus, the vaccine not only prevents painful and disfiguring shingles but also reduces the risk of long-term diseases like dementia and heart attacks.

These studies don’t show that the shingles vaccine itself prevents dementia or heart attacks, but it prevents the disease that probably increases the risk of these outcomes.

This post will examine this new research and determine if it provides solid evidence for the shingles vaccine reducing cardiovascular events.

Shingles and the vaccine

One of the complications of contracting chickenpox, caused by the Varicella zoster virus (VZV), a herpesvirus, is that the body’s immune system does not destroy the virus. Once the symptoms of chickenpox disappear, the virus hides (it does not do this consciously, it’s a virus) in the dorsal root ganglion, a bundle of nerve fibers at the bottom of the spinal column. The virus hangs out there, hidden from the body’s immune system.

We are unsure why it does this, but it may be an evolutionary adaptation to survive until later, when it can reproduce and reinfect the victim.

Even though the body generated an immune response to the original zoster virus infection, several years or decades after the initial infection, the adaptive immune response against the virus wanes or disappears. Due to other unknown factors, possibly stress or other infections like COVID-19, the Varicella zoster virus “moves” along the nerve bundles and begins a secondary infection with much more serious consequences to the individual.

This second infection is called herpes zoster, more commonly known as shingles. This infection usually happens when the patient is older than 50, although it can happen at any time, occasionally even in young adults. 

Even though the same virus causes chickenpox and shingles, shingles was given a different name, herpes zoster, probably because it was originally thought to be caused by a similar, but unrelated virus. However, herpes zoster is not a formal name based on biological binomial nomenclature. We now know that the virus Varicella zoster causes both chickenpox and shingles.

Shingles is an entirely unpredictable disease. It appears at random points in time in response to unknown causes. Once shingles appear, they can be painful, depending on the location of the outbreak. It can cause blindness, disfigurement of the infected area, permanent pain, and other conditions.

Shingles can be treated with antiviral drugs, but only if the infection is recognized and treated within 24-72 hours, a time frame that might not allow most individuals to get to their doctor. The initial symptoms may appear like acne or other skin conditions, which many people might ignore. After 72 hours, the disease has to run its painful and dangerous course. Shingles pain may last for weeks, months, or even years after the blisters have healed – this is not a trivial disease.

Furthermore, shingles is not a one-time event. Even if you develop shingles, it may return in months or years, so it is important to be vaccinated even if you have had shingles.

Almost all individuals in the US aged 50 years and older have been infected with VZV and are therefore at risk for shingles. There’s a growing body of evidence that herpes viruses, including VZV, can influence cognitive decline.

The only way to prevent a shingles infection is to boost the immune system with a new vaccine against the zoster virus. The CDC recommends Shingrix (sometimes called the zoster vaccine, available in the USA), a relatively new, safe, and effective vaccine that prevents shingles. Shingrix has replaced the older shingles vaccine, Zostavax, because it is much more effective.

There is another way to prevent shingles — never get chickenpox in the first place. Of course, we have a vaccine for that, the chickenpox (or varicella) vaccine.

The CDC recommends the vaccine for individuals 50 years or older. In addition, the vaccine should also be given to individuals who are 19 years or older and have a compromised immune system. Other countries have different recommendations, so you should check the public health authorities for your home country.

So let’s be clear about a couple of things. First, you are only at risk for shingles if you contract chickenpox. Second, children who have received the chickenpox vaccine will probably never develop shingles as they age.

Shingles vaccine and cardiovascular events paper

In a paper published on 5 May 2025 in the European Heart Journal, Dong Keon Yon, PhD, Kyung Hee University College of Medicine, Seoul, South Korea, and colleagues, examined data from comprehensive information of 2,207,784 individuals aged 50 years and greater from South Korea from 1 January 2012 to 31 December 2021.

The risk of incident cardiovascular outcomes after live shingles vaccination was compared to unvaccinated individuals. The primary outcome was the risk of cardiovascular diseases, including heart failure, cerebrovascular disorders, ischaemic heart disease, clotting disorders, and dysrhythmia.

Here are the key results:

• The researchers observed a 26% decrease in major adverse cardiovascular events in the vaccinated population.
• 26% decrease in heart failure.
• 24% decrease in cerebrovascular disorders.
• 22% decrease in ischaemic heart disease.
• 22% decrease in thrombotic disorders.
• 21% decrease in dysrhythmia.
• Finally, there was a 23% decrease in overall cardiovascular events.

The decrease in cardiovascular disease risk was more pronounced among males, individuals aged less than 60 years, those with unhealthy lifestyle habits, and those from low-income households and rural residents.

The researchers concluded:

These findings suggest that live zoster vaccination may be beneficial as a public health strategy with potential implications for cardiovascular disease burden in the general population. This strategy may help address health disparities and mortality linked to cardiovascular complications.

Summary

This was a large, well-designed cohort study that carefully compared the incidence of cardiovascular events between a group that received the shingles vaccine and an unvaccinated group. The researchers showed that there was a statistically significant reduction in the risk of all types of cardiovascular events in the vaccinated individuals.

There are some weaknesses in this study. First, it only included South Koreans who may have demographic differences that enhanced the lowering of cardiovascular risk. Second, it is an observational study, so it may not show causality between the vaccine and cardiovascular events.

However, I’m impressed by the analysis performed by the researchers, and I think it provides intriguing and powerful evidence that the shingles vaccine, by preventing shingles, reduces the risk of major cardiovascular diseases. Remember, even though we are getting more and more evidence that the vaccine reduces the risks of many diseases, that’s all a bonus. Its primary function is to prevent shingles, a nasty disease.

I’m up-to-date on my shingles vaccination. I now feel happy that it may reduce my risk of a heart attack. If you’re eligible, get the shingles vaccine so you can also feel happy.

Citations

• Lee S, Lee K, Oh J, Kim HJ, Son Y, Kim S, Park J, Kang J, Pizzol D, Lee J, Woo HG, Lee H, Yon DK. Live zoster vaccination and cardiovascular outcomes: a nationwide, South Korean study. Eur Heart J. 2025 May 5:ehaf230. doi: 10.1093/eurheartj/ehaf230. Epub ahead of print. PMID: 40324473.

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