Ask the Doctors: Do adults need a chickenpox booster?

Dear Doctor: My daughter had the chickenpox vaccine as a child, so she never had chickenpox. She’s now an adult. Should she get a booster?

Dear Reader: That’s an excellent question. The chickenpox (Varicella) vaccination has been widely used in the United States since 1996. Given in a two-dose schedule at 12 to 15 months and at 4 to 6 years, the vaccine has significantly reduced the incidence of chickenpox among the population. If your child had the vaccine 20 years ago, she is indeed still protected from getting chickenpox.

But — and this is concerning — she’s less protected than when she got the vaccination. That’s especially important because contracting chickenpox as an adult can lead to an increased risk of pneumonia and even death.

Children in some pockets of the United States are less likely to have been vaccinated, and thus outbreaks of chickenpox occur. This is also true for other countries with more spotty vaccination rates than the U.S. A 21-year-old may be more susceptible to getting the virus if he or she visits those areas.

The good news is that, in most areas of this country and the developed world, the vaccine has significantly reduced the circulation of the chickenpox virus in the population, so your daughter will be less likely to be exposed to it. And you can take solace in the fact that, if your daughter does develop chickenpox, it probably won’t be as severe as someone who was never vaccinated. That’s because she does have some immunity from her previous vaccination, so she will be less likely to get the severe complications that can occur in adults.

That said, there are many unknowns regarding what will occur later in life when your daughter is in, say, her 50s and her immunity to the virus has waned further. Currently, neither the federal Centers for Disease Control and Prevention nor the American Academy of Pediatrics recommends a chickenpox booster. That could change over time — especially for those people traveling to areas where chickenpox is prevalent.

We will understand more about the vaccine and its protective powers as this first generation of people who received the vaccine gets older — and as doctors and patients ask these important questions.

Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.