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Officials urge everyone over age 60 to get the shingles vaccine, which can help curb the inflammation associated with both shingles and stroke. Getty Images
  • A new study concludes that the risk of stroke in people over 50 can be reduced by getting a shingles vaccine.
  • Researchers say shingles increases a person’s risk of stroke, so getting the preventive vaccine reduces the chance of getting the disease and, therefore, the risk of stroke.
  • Researchers reported the effectiveness of the shingles vaccine decreases as people get older.

Shingles is bad enough on its own — but the painful illness may also increase your risk of stroke.

Conversely, getting vaccinated against shingles may also help prevent stroke, especially among older adults.

Those are the conclusions from a new study that will be presented next week at the annual American Stroke Association’s International Stroke Conference 2020 in Los Angeles.

Researchers said they discovered that study participants who received the vaccine Zostavax (zoster vaccine live) reduced their risk of both types of stroke — ischemic, caused by blood clots, and hemorrhagic, caused by bleeding.

The protective effect was strongest among people ages 66 to 79, according to the study led by Quanhe Yang, PhD, senior scientist at the Centers for Disease Control and Prevention (CDC).

“Approximately 1 million people in the United States get shingles each year, yet there is a vaccine to help prevent it,” Dr. Yang said in a statement. “Our study results may encourage people ages 50 and older to follow the recommendation and get vaccinated against shingles. You are reducing the risk of shingles and at the same time you may be reducing your risk of stroke.”

Shingles is a viral infection caused by the chickenpox virus.

It causes skin blisters and can have serious complications, including long-term recurring pain and, in rare cases, blindness, hearing loss, and death.

An estimated 99 percent of people ages 40 and older in the United States carry the dormant chickenpox virus.

That puts most Americans at risk of shingles, which is a reactivation of the illness.

One in three Americans who’ve had chickenpox develop shingles at some point in their lives, Yang noted. The disease is most common among people ages 50 and older.

Zostavax can prevent about half of shingles cases, studies have shown. However, its effectiveness declines with age, from 64 percent among people 60 to 69 years old, to about 41 percent for ages 70 to 79, to about 18 percent among those 80 years and older.

For those who get the vaccine, the protective benefits against stroke are significant, according to the researchers in the new study.

Among those under age 80, the vaccine reduced the risk of stroke by nearly 20 percent. For those older than 80, risk was lowered by about 10 percent.

Overall, getting the shingles vaccine lowered the risk of stroke by about 16 percent, including reducing the risk of ischemic stroke by about 18 percent and the risk of hemorrhagic stroke by about 12 percent.

The findings were based on a review of Medicare health records of more than 1 million beneficiaries ages 66 or older who had no history of stroke and who were vaccinated with Zostavax between 2008 and 2014.

Participants were followed for an average of about 4 years and compared to a similar group of Medicare recipients who didn’t receive the vaccine.

Dr. Lawrence Schmetterer, a thoracic and vascular surgeon based in Youngstown, Ohio, told Healthline that the shingles virus is associated with a 61 percent increase in stroke risk.

Experts say that inflammation caused by shingles is what increases stroke risk.

“We know that other vaccines, like the flu shot, also decrease stroke risk,” Dr. Jason Tarpley, a stroke and interventional neurologist and director of the Stroke and Neurovascular Center at Providence Saint John’s Health Center in Santa Monica, California, told Healthline.

“When you get the flu or shingles you do have a general increase in inflammation, so if you reduce that you can reduce stroke risk,” he said.

The mechanism by which inflammation may increase stroke risk is unclear, although Schmetterer said some studies have shown that it causes harmful changes, or “remodeling,” of intracerebral blood vessels.

Tarpley said that anecdotally, stroke doctors often see people who have had strokes on the heels of a recent illness.

“Flu season and winter are our busy season for strokes and that’s probably why,” he said.

Schmetterer cautioned that the vaccine needs to be taken proactively to provide protective benefits.

“Multiple articles were published in 2019 indicating that neither antiviral treatment nor the shingles vaccine were effective in reducing the risk of stroke in individuals once they had contracted the varicella zoster viral manifesting as shingles,” he said.

At the time of the study, Zostavax was the only shingles vaccination available.

A newer vaccine, Shingrix (adjuvanted, non-live recombinant shingles vaccine) is more than 90 percent effective at preventing shingles among individuals ages 50 and older.

The new vaccine presumably would also reduce risk of shingles-related stroke, although such studies haven’t yet been conducted.

The CDC recommends that everyone over the age of 60 get the shingles vaccine. Shingrix is now recommended over Zostavax.