For people who grew up before a vaccine was available, chickenpox is largely remembered as an unpleasant experience that almost every child suffered through. The highly contagious disease tore through communities, leaving behind more than a few lasting scars.
For many children, chickenpox was much more than a week or two of itchy discomfort. It was a serious and sometimes life-threatening infection.
Prior to the chickenpox vaccine’s introduction in 1995, 90 percent of children got chickenpox. Those children grew into adults with an increased risk of developing shingles, a disease caused by the same virus—varicella-zoster—as chickenpox, which lies dormant in the body for decades.
The vaccine changed all that, nearly wiping out chickenpox in the U.S. in under three decades. The vaccine has been so successful that some people falsely believe the disease no longer exists and that vaccination is unnecessary. This couldn’t be further from the truth.
Vaccination spares children and adults from the misery of chickenpox and the serious short- and long-term risks associated with the disease. The CDC estimates that 93 percent of children in the U.S. are fully vaccinated against chickenpox. However, outbreaks can still occur among unvaccinated and under-vaccinated populations.
Here are some of the many reasons why we still need chickenpox vaccines.
Chickenpox is more serious than you may remember
For most children, chickenpox lasts around a week. Symptoms vary in severity but typically include a rash of small, itchy blisters that scab over, fever, fatigue, and headache.
However, in one out of every 4,000 chickenpox cases, the virus infects the brain, causing swelling. If the varicella-zoster virus makes it to the part of the brain that controls balance and muscle movements, it can cause a temporary loss of muscle control in the limbs that can last for months. Chickenpox can also cause other serious complications, including skin, lung, and blood infections.
Prior to the U.S.’ approval of the vaccine in 1995, children accounted for most of the country’s chickenpox cases, with over 10,000 U.S. children hospitalized with chickenpox each year.
The chickenpox vaccine is very effective and safe
Chickenpox is an extremely contagious disease. People without immunity have a 90 percent chance of contracting the virus if exposed.
Fortunately, the chickenpox vaccine provides lifetime protection and is around 90 percent effective against infection and nearly 100 percent effective against severe illness. It also reduces the risk of developing shingles later in life.
In addition to being incredibly effective, the chickenpox vaccine is very safe, and serious side effects are extremely rare. Some people may experience mild side effects after vaccination, such as pain at the injection site and a low fever.
Although infection provides immunity against future chickenpox infections, letting children catch chickenpox to build up immunity is never worth the risk, especially when a safe vaccine is available. The purpose of vaccination is to gain immunity without serious risk.
The chickenpox vaccine is one of the greatest vaccine success stories in history
It’s difficult to overstate the impact of the chickenpox vaccine. Within five years of the U.S. beginning universal vaccination against chickenpox, the disease had declined by over 80 percent in some regions.
Nearly 30 years after the introduction of the chickenpox vaccine, the disease is almost completely wiped out. Cases and hospitalizations have plummeted by 97 percent, and chickenpox deaths among people under 20 are essentially nonexistent.
Thanks to the vaccine, in less than a generation, a disease that once swept through schools and affected nearly every child has been nearly eliminated. And, unlike vaccines introduced in the early 20th century, no one can argue that improved hygiene, sanitation, and health helped reduce chickenpox cases beginning in the 1990s.
Having chickenpox as a child puts you at risk of shingles later
Although most people recover from chickenpox within a week or two, the virus that causes the disease, varicella-zoster, remains dormant in the body. This latent virus can reactivate years after the original infection as shingles, a tingling or burning rash that can cause severe pain and nerve damage.
One in 10 people who have chickenpox will develop shingles later in life. The risk increases as people get older as well as for those with weakened immune systems.
Getting chickenpox as an adult can be deadly
Although chickenpox is generally considered a childhood disease, it can affect unvaccinated people of any age. In fact, adult chickenpox is far deadlier than pediatric cases.
Serious complications like pneumonia and brain swelling are more common in adults than in children with chickenpox. One in 400 adults who get chickenpox develops pneumonia, and one to two out of 1,000 develop brain swelling.
Vaccines have virtually eliminated chickenpox, but outbreaks still happen
Although the chickenpox vaccine has dramatically reduced the impact of a once widespread disease, declining immunity could lead to future outbreaks. A Centers for Disease Control and Prevention analysis found that chickenpox vaccination rates dropped in half of U.S. states in the 2022-2023 school year compared to the previous year. And more than a dozen states have immunization rates below 90 percent.
In 2024, New York City and Florida had chickenpox outbreaks that primarily affected unvaccinated and under-vaccinated children. With declining public confidence in routine vaccines and rising school vaccine exemption rates, these types of outbreaks will likely become more common.
The CDC recommends that children receive two chickenpox vaccine doses before age 6. Older children and adults who are unvaccinated and have never had chickenpox should also receive two doses of the vaccine.
For more information, talk to your health care provider.