If you had chickenpox as a child, you might think the disease is behind you. But varicella zoster, the virus that causes chickenpox, can remain dormant in the body and resurface later in life, causing a sometimes debilitating condition called shingles. 

Shingles affects up to a third of adults, according to the Centers for Disease Control and Prevention (CDC). Older adults are more likely to get shingles; most cases occur in people 50 and older.

At first, shingles causes a painful, blistered rash that usually goes away in a few weeks. But the older you are, the more likely it is that the condition will cause postherpetic neuralgia (PHN), severe pain in the area of the rash that can linger even after the skin problem clears up, sometimes for months or years.

Treating this pain "remains a medical conundrum," says Kathleen Dooling, M.D., a CDC medical officer.

That's why the best strategy is to protect yourself from shingles in the first place by getting vaccinated. Here's what you need to know.

Why the Shingles Vaccine is Important

Because the condition is caused by a virus that's already inside of you, the only way to protect yourself is by vaccination. There are two shingles vaccines: Zostavax, available since 2006, and Shingrix, approved in 2017.

The CDC recommends that people age 50 and older get two doses of Shingrix two to six months apart. It's more than 90 percent effective at preventing shingles, and studies suggest that the protection is long-lasting. (Zostavax is only 51 percent effective.)

More on Vaccines

You should get Shingrix even if you're not sure whether you had chickenpox, and even if you already had the Zostavax vaccine or shingles itself, the CDC says. Check with your doctor about how long to wait after a bout of shingles to get the vaccine. 

Serious adverse reactions to shingles vaccines are rare, according to the CDC. But the side effects of Shingrix tend to be a little more bothersome than you might experience with other vaccines. A February 2019 study reported that about 24 percent of people who had Shingrix developed a fever, and about 20 to 23 percent had redness or pain at the injection site. Fatigue and muscle aches are also possible. Dooling recommends taking it easy the day after getting the shot. Side effects generally go away within a few days. 

Trouble Finding the Vaccine?

Because of a Shingrix shortage in the U.S., this preferred shingles vaccine may not be easy to find. The manufacturer is steadily shipping supplies to healthcare providers, says Dooling, but the wait may still be weeks or months.

The CDC has a vaccine finder tool that can help you. Just be sure to call the doctor or pharmacist before you head out to make sure Shingrix is really in stock. You can also ask whether he or she can call you when it's available, or whether you can be put on a waitlist.

The CDC recommends two doses of Shingrix two to six months apart. If you can't find a second dose within two to six months of getting the first, however, there's no need to restart the series. Just get it as soon as you can.  

Treating Shingles

Three antiviral drugs are available to treat shingles: acyclovir (Zovirax and generic), famciclovir (Famvir and generic), and valacyclovir (Valtrex and generic). Treatment is most effective if begun within 72 hours of the first symptoms, so see your doctor immediately if you think you may have shingles.

Antiviral drugs can lessen the severity of pain from the rash and help it heal more quickly, though it's unclear whether they can reduce the likelihood that you'll develop postherpetic neuralgia, according to Dooling.

Different types of drugs have been found to help ease postherpetic neuralgia pain in some patients. They include anticonvulsant medications such as gabapentin (Neurontin and generic), tricyclic antidepressants such as amitriptyline (Amitid and others and generic), and a recently approved lidocaine patch (ZTlido).

Editor's Note: This article also appeared in the August 2019 issue of Consumer Reports On Health.