How the Shingles Vaccine May Do More Than Prevent Shingles — Including Lowering Dementia Risk
Beyond preventing a painful viral infection, the shingles vaccine may also protect against dementia, stroke, and heart disease. Here's what experts want you to know.
The Case for Getting Vaccinated Against Shingles
Shingles affects roughly one in three Americans at some point in their lifetime — yet fewer than 35% of adults over 60 have received the vaccine that could protect them. Amid what some physicians describe as widespread "vaccine fatigue," health experts are urging the public to reconsider, especially as mounting research suggests the shingles vaccine may offer benefits that extend well beyond preventing a painful rash.
What Exactly Is Shingles?
Shingles is a viral illness triggered by the varicella-zoster virus — the same pathogen responsible for chickenpox. However, the two conditions are not interchangeable. Chickenpox is the initial infection; shingles occurs years or even decades later when the dormant virus reactivates and travels along nerve pathways to the surface of the skin.
The first sign is usually pain, followed by touch sensitivity, itching, and eventually a red rash with fluid-filled blisters. Fever, headache, and fatigue are also common. The rash typically appears as a stripe of blisters on one side of the body, though it can technically develop anywhere.
Who Is Most at Risk?
While most people recover without serious complications, between 1% and 4% of shingles patients require hospitalization. Older adults and those with compromised immune systems face the greatest risk of severe illness. The Centers for Disease Control and Prevention (CDC) reports that fewer than 100 people in the United States die from shingles each year.
After the initial chickenpox infection resolves, the varicella-zoster virus does not disappear — it retreats into a cluster of neurons near the spinal cord called the dorsal root ganglion, where it lies dormant. What triggers reactivation remains unclear, but contributing factors include a weakened immune system, elevated stress levels, and certain medical conditions such as diabetes.
How Does Shingles Spread?
A person with active shingles becomes contagious once blisters form and remains so until those blisters have dried and crusted over — a process that generally takes seven to ten days, with full blister resolution occurring within two to four weeks. The virus can be transmitted through direct contact with blister fluid or by inhaling particles from open blisters.
It's important to note: if someone has never had chickenpox or been vaccinated against it, exposure to shingles could result in chickenpox — not shingles. You cannot develop shingles without first having had the varicella-zoster virus in your system.
Understanding Your Vaccination Options
There are currently two chickenpox vaccines licensed in the United States. Adults who were never vaccinated as children and have no history of chickenpox can still receive this vaccine. Introduced in 1995, the chickenpox vaccine raises hopes that future generations may avoid both chickenpox and shingles altogether. Rare breakthrough cases can still occur, and a blood test can confirm whether prior vaccination has maintained immunity.
For shingles specifically, the vaccine used in both the US and the UK is called Shingrix. Unlike the childhood chickenpox vaccine, Shingrix is designed to meet the immune needs of older adults.
How Effective Is Shingrix?
According to the CDC, Shingrix is more than 90% effective at preventing shingles in adults aged 50 and older with healthy immune systems. Even if a vaccinated person does contract the illness, the vaccine significantly reduces severity. It can also help prevent recurrence in individuals who have already experienced shingles.
Beyond prevention, vaccination dramatically reduces the likelihood of serious complications. One of the most debilitating is postherpetic neuralgia — a condition characterized by persistent burning nerve pain that can linger for months or even years after the rash clears. Dr. Rosanne Leipzig, professor emeritus of geriatrics and palliative medicine at the Icahn School of Medicine at Mount Sinai, notes that 10% to 18% of shingles patients develop this condition, with risk climbing sharply with age. Other serious complications can include pneumonia, encephalitis, and hearing or vision loss.
Side Effects: What to Expect
The CDC reports no serious side effects associated with Shingrix, though some patients do experience temporary discomfort. Dr. Andrew Wallach, ambulatory care chief medical officer at NYC Health + Hospitals, notes that side effects sometimes discourage patients from completing the two-dose series.
Common reactions include soreness and swelling at the injection site, typically resolving within a day or two. Flu-like symptoms — mild fever and body aches — may also occur and generally subside within a few days. Interestingly, side effects tend to be more pronounced after the first dose and less intense after the second. Adults over 70 also appear to experience fewer side effects than their younger counterparts.
Who Should Get Vaccinated and When?
The CDC recommends two doses of Shingrix for all adults 50 years and older, with doses administered two to six months apart. Adults aged 19 and older with weakened immune systems are also advised to get vaccinated, with the option of spacing doses just one to two months apart.
Certain individuals should not receive the vaccine, including those currently experiencing a shingles outbreak, those who are pregnant, and anyone who has previously had an allergic reaction to Shingrix.
Although younger adults are increasingly being diagnosed with shingles — a trend not yet fully understood — vaccination is not currently recommended before age 50 for otherwise healthy individuals. There is no established evidence of benefit for early vaccination in this group, and it is unlikely to be covered by insurance.
As for duration of protection, studies suggest Shingrix remains effective for anywhere from four to eleven years. Receiving only one dose significantly reduces its effectiveness. In the United States, most insurance plans and Medicare Part D cover the full cost of vaccination for eligible individuals.
A Surprising Bonus: Brain and Heart Protection
Perhaps the most compelling emerging reason to get vaccinated is evidence linking shingles vaccination to reduced risks of dementia, stroke, and heart attack.
Multiple studies have identified an association between shingles infection and elevated dementia risk. While some researchers have found conflicting results, and much of the earlier research focused on an older, now-discontinued vaccine, newer findings related to Shingrix are generating significant interest in the scientific community.
"Dementia is complex, and there are likely many contributing factors to its onset and progression," says Emily Rayens, a postdoctoral fellow at the Kaiser Permanente Southern California Department of Research and Evaluation. Nevertheless, she adds, there is now "strong evidence for the relationship between shingles vaccines and a lower risk of dementia."
For a vaccine that already does an impressive job of preventing a painful and potentially serious illness, the prospect of additional neurological and cardiovascular protection makes the case for vaccination even more compelling.
The Bottom Line
Despite the availability of a highly effective vaccine, shingles vaccination rates in the United States remain disappointingly low. With evidence continuing to build around its broader health benefits — including potential protection against dementia — experts agree that more adults should be having conversations with their healthcare providers about Shingrix. The temporary discomfort of two injections may be a small price to pay for long-term protection.
