Shingles causes excruciating, disabling, burning pain that may last for weeks, months, or years. A new study from Harvard researchers shows that it also increases the risk for a heart attack or stroke. The study, published in the Journal of the American Heart Association, found a 30 percent increased risk. Called cardiovascular events, these heart attacks and strokes were most likely to occur five to 12 years after shingles.

One in three people over age 50 can expect to get shingles. In view of these findings, the researchers strongly encourage people to get the new vaccine to prevent the misery of shingles and the increased risk of a heart attack or stroke. According to the Centers for Disease Control and Prevention, the vaccine is 97 percent effective in adults ages 50 to 70.

How was the study done?

The research team used three long-term, ongoing studies to track how often a stroke, heart attack, or procedure to clear a blocked heart artery (revascularization) occurred after a shingles infection. In these studies, adults between the ages of 25 and 75 have been filling out questionnaires every two years, reporting all their health information.

The studies started between 1976 and 1989, and included about 30,000 men and 174,000 women. The research team compared cardiovascular events between people who had shingles before the cardiovascular event and those who never had shingles. These were the key findings:

  • There was a 38 percent increased risk of a stroke five to eight years after shingles, and a 28 percent risk at nine to 12 years.
  • There was a 16 percent increased risk of a heart attack or revascularization procedures five to eight years after shingles, and a 25 percent risk at nine to 12 years.

The cause of these cardiovascular events is likely inflammation of the large and small blood vessels supplying the heart and the brain. This inflammation, called vasculopathy, slows down blood supply through these blood vessels and may cause a blocked vessel, resulting in stroke or heart attack. Viral inflammation of blood vessels is not only seen in herpes virus, but it also occurs in COVID and other viral infections.

Troubled vaccine history

Despite the pain and other risks of shingles, less than 50 percent of people over age 60 are getting vaccinated, according to the CDC.

Part of the problem is the old shingles vaccine, Zostavax, which was made from a live virus. It was not very effective and, because it was a live virus, it could cause shingles in people with weak immune systems or chickenpox in unvaccinated babies. It was only about 50 percent effective for people over age 50 and got less effective with age. Zostavax is no longer available in the United States.

An improved vaccine

Shingrix, the new vaccine, is an attenuated virus, meaning it is made from pieces of the shingles virus. It is approved for adults ages 50 and older. It is also approved for people with a weak immune system, starting at age 19. For adults ages 50 to 69, Shingrix is 97 percent effective. It continues to be over 90 percent effective in people ages 70 and older. Protection lasts for about seven years. Shingrix is given in two injections two to six months apart.

If you already had shingles, you should still get the vaccine because shingles can come back. The risks and pain of shingles far outweigh any concerns about the new vaccine. Getting the new vaccine should be an obvious choice.

What is Shingles?

If you’ve ever had chickenpox, the varicella zoster virus is already in your body. (If you were born before 1979, there is more than a 99 percent chance that you did.) After the chickenpox infection subsides, the virus hibernates in the roots of the nerve cells that supply feeling to your skin. For a variety of reasons, that virus can be reactivated later in life. Possible causes are stress, a long illness, cancer, diabetes, or taking any medication that weakens the immune system. It then travels down the nerve to the skin and causes the painful rash that is shingles.

The rash will appear in the area supplied by the nerve root, usually on one side of the body in the area of your face, neck, chest, or torso. It is extremely painful and lasts for up to four weeks. People with weaker immune systems are more likely to get shingles and more likely to have more severe shingles. 

Other risks

The most common complication after shingles is postherpetic neuralgia (PHN), or severe pain that can last for months, years, or longer.

If you have shingles in the nerve that supplies the face (the facial nerve), you may have facial paralysis, loss of hearing, and dizziness.

If the branch of the facial nerve that goes to the eye is affected, you may have inflammation and damage to the eye resulting in blurred vision. Another common complication is skin bacteria infecting the rash.

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