This article originally appeared in the San Francisco Chronicle on February 6, 2013.
For the first time in history, a generation is growing up vaccinated against chicken pox – a childhood disease that more than 90 percent of Americans have had. But what does the vaccine mean for shingles, the disease caused by the same virus? The answer, doctors say, isn’t clear, and it won’t be for about 40 years, when the first of the vaccinated generation reach middle age.
Shingles usually hits adults over 50, causing a rash and pain that can last for weeks or months. It occurs when the varicella virus reactivates. The virus can lie dormant in the body’s nerves for years, but can spring into action when an aging adult’s immune system proves too weak to fight it off. Shingles strikes more than 1 million Americans annually.
The chicken pox vaccine, approved by the Food and Drug Administration in 1995, involves injecting children with a live but weakened varicella virus. The body can safely fight it off, producing chicken pox immunity.
Dr. Ann Arvin, professor of pediatrics and infectious diseases at Stanford, says doctors aren’t yet sure whether this weakened virus will produce shingles immunity, too, or whether it is strong enough to cause shingles years later. In the meantime, she offers advice to adults over 50 who fear shingles’ wrath: Get the shingles vaccine. Zostavax, which is also created from a weakened form of varicella, boosts adults’ ability to fight the existing virus if it reactivates. The FDA approved the vaccine for people 50 and over in 2011, after a study of 22,000 people showed that people who had the vaccine were 70 percent less likely to get shingles within a year than people who received a placebo. The vaccine’s protection lasts at least six years, and research is under way to determine if it lasts longer. (Source: 1.usa.gov/dKiyWp)