Recently a friend of ours was cleaning out a box of books from her childhood. She handed me a copy of a book titled, quite simply, Chicken Pox. The cover showed a little boy in his jammies, scratching wildly at a bunch of red itchy bumps.
My daughters were utterly puzzled. What was this book about? Was this a real illness that kids got? Why hadn’t anyone they knew had it?
The mystery around chickenpox experienced by my kids, ages 7 and 9, is a testament to the power of vaccines. Today's children are of the post-chickenpox (varicella) vaccine generation and as such, they simply haven’t seen children with chickenpox or even really heard of it. Contrast that to my childhood in the mid-1980s, when it seemed like everyone in my class got chickenpox at the same time (I can still remember that incessant itch!).
Nowadays most children are vaccinated against chickenpox, and just two doses of the vaccine (typically received at age 12 to 15 months and again between age 4 and 6) provide over 90 percent effectiveness against the disease. As a result, there has been an overwhelming decrease in chickenpox cases in the United States since the vaccine was licensed in 1995—from 4 million people infected annually (of whom about 10,000 were hospitalized and roughly 150 died) to fewer than 1 million infected annually.
But this doesn’t hold true everywhere in the country. Children in some communities are still getting infected and spreading chickenpox simply because they aren’t vaccinated. For instance, recently a private school in Asheville, N.C., experienced the worst chickenpox outbreak the state had seen in over 20 years. In a matter of weeks, at least 36 children were infected with chickenpox at the Asheville Waldorf School (also known as the Azalea Mountain School), which also happens to have one of the highest rates in the state of religious exemptions from school vaccination requirements. In the 2017-18 school year, two-thirds of kindergarteners at the school had a religious exemption, meaning they were either unvaccinated or missing some recommended vaccines.)
This is a scary trend, but not an isolated one: According to the CDC, while the overall proportion of vaccinated children in the U.S. remains high, the number of unvaccinated children between ages 19 months and 35 months has quadrupled since 2001, from 0.3 percent to 1.3 percent. This is in large part why the country is seeing a resurgence of other vaccine-preventable diseases, such as measles and pertussis.
In fact, New York state is currently experiencing the worst outbreak of measles in decades, primarily among unvaccinated people in the Orthodox Jewish community.
Why you should care
You may be thinking, so what? Maybe your kids are all grown up and already had chickenpox. Or maybe you’re thinking that chickenpox isn’t that serious, so what’s the big deal if some outbreaks happen?
But chickenpox can be a dangerous illness for children—as well as for adults, who can still catch it if they didn't have chickenpox as a child and haven't been vaccinated against it. Because chickenpox creates open sores on the body, it can lead to bacterial infections of the skin and soft tissues (muscles, fat, tendons, and ligaments). Similar to other viruses, chickenpox can also leave a person open to secondary bacterial infections like pneumonia.
In extreme cases chickenpox can lead to brain inflammation, severe bleeding due to low platelet counts, secondary bacterial bloodstream infection (sepsis), and even death. Chickenpox can be especially dangerous in immunocompromised people (such as those infected with HIV/AIDS), pregnant women, and older adults.
There’s another important reason to vaccinate children against chickenpox: It protects them against unwitting infection by an older adult with shingles, a painful rash caused by the same virus as chickenpox (varicella zoster). Once a person has been infected with the virus, it can reactivate in their body later in life as shingles.
Since shingles is contagious, it can cause chickenpox in kids who haven’t had the disease and aren’t immunized, meaning there is a risk that Grandma or Grandpa could infect their unvaccinated grandchild. And of course, by vaccinating your children against chickenpox, you also protect them from later developing shingles themselves—either in adulthood or, more rarely, while they're still children. Indeed, a study of more than 6 million children, published in June 2019 in Pediatrics, found that those who'd received the varicella vaccine were 78 percent less likely to develop pediatric shingles over a 12-year period than those who weren't vaccinated.
Bottom line: Vaccinating children against chickenpox protects not only them but others as well—not just in childhood but for years to come. Additionally, all adults age 50 and older should get the shingles vaccine, regardless of whether they had chickenpox as children.
Originally published January 2019. Updated June 2019.