Once a rite of passage, chicken pox may be going to the way of short pants and stickball. This is great news for kids—since the chicken pox vaccination was introduced for children in 1995, the Centers for Disease Control says that more than 3.5 million cases are prevented every year—but there is concern over what that means for us grown-ups.

Chicken pox is caused by the varicella zoster virus (VZV). About 99.5 percent of Americans over 40 had chicken pox as a kid. No matter how many oatmeal baths and dots of calamine lotion their parents gave them, VZV hangs out in the body’s nervous system and hides out, doing nothing at all, for years, maybe decades, maybe forever.

For reasons that doctors don’t understand, sometimes the virus turns back on in adulthood, causing shingles, which is often much more painful. Shingles usually starts on one side of the face or body as pain, itching or tingling that lasts for one to five days before turning into a nasty rash. It can also come with fever, headache, chills and upset stomach, and may lead to severe nerve pain that can last for months or years after the rash has cleared up. And a January 2014 study done in the U.K. found that it significantly increases the risk of stroke and other vascular diseases, probably because of the inflammation that accompanies a viral infection as serious as shingles.

Shingles is very prevalent even though it isn’t highly contagious. (Interestingly, if you didn’t have chicken pox as a kid, you could get chicken pox from touching someone with shingles.) Nearly one-third of all American adults will develop shingles at some point, typically after the age of 50. There are an estimated 1 million cases of shingles each year in the U.S., and the incidence has increased noticeably over the past few decades. Why there has been a rise isn’t clear, but some wonder whether the chicken pox vaccine is to blame.

The theory is that exposure to kids with chicken pox bolsters adults’ immunity against VZV, and therefore fewer itchy kids leaves us less able to fight off the virus if and when it reactivates in our systems. Researchers from the CDC tested this theory in a December 2013 study published in the Annals of Internal Medicine and found that the link between the chicken pox vaccine and increased shingles rates doesn’t hold up. They concluded that the incidence rate was already on the rise when parents first started vaccinating their children in the mid 90s.

The best course of action for parents and non-parents alike is to vaccinate your children for chicken pox and vaccinate yourself against shingles. The shingles vaccine is recommended for adults age 60 and up. (We think the data really support vaccinating all over age 50.) Currently, fewer than 15 percent of adults over age 60 get the vaccine. But if we can get that number up, we can bring the rate of shingles down the way we have for chicken pox.

Let’s scratch this itch once and for all.

READ MORE: Why You Need an Annual Flu Shot