Should you get the shingles vaccine?

Content provided by the Faculty of the Harvard Medical School

If you're 60 or older, the official recommendations say yes. But pluses and minuses make for a complicated equation.

Vaccinations aren't just kid stuff anymore, and now there's another one that older Americans are being urged to get in addition to their annual flu shot, the pneumococcal pneumonia vaccine at age 65, and a tetanus booster every 10 years. The Advisory Committee on Immunization Practices, the group that sets vaccine policy for Americans, made its official recommendation for the shingles vaccine in 2008. All Americans ages 60 or older should get the shot, the committee says, even if they've already had shingles.

The committee's recommendation of the need for the vaccine after shingles is a departure from the FDA-approved instructions for the vaccine (the package insert), which is silent on the subject. And it contradicts a question-and-answer sheet posted on the agency's Web site when the vaccine was approved, which suggests that it is unnecessary after you've had shingles because "it's unlikely that people who have had shingles will suffer from them again."

It's difficult to gauge the practical effects of the recommendations. Doctors may be more inclined to urge their patients to get the vaccine. But insurance coverage is spotty. For example, Medicare Part B, which covers flu shots and pneumococcal vaccine, doesn't cover the shingles vaccine. Pricing varies, but the total bill, including the doctor's fee, can come to several hundred dollars. And the vaccine is no guarantee: results from the Shingles Prevention Study, the 39,000-person trial that laid the groundwork for FDA approval, showed that about half the time the vaccine did not protect people against shingles, although it did do a better job in preventing postherpetic neuralgia, prolonged pain that develops and continues after the typical rash disappears in about 10% to 15% of people with shingles.

Another reason people have doubts about the vaccine is fear that it could give them shingles. We've gotten letters from several readers along those lines. The shingles vaccine is made with a weakened virus, and there are rare instances of "live attenuated" vaccines causing the very disease that they're supposed to prevent. It doesn't happen often, but the live attenuated version of the polio vaccine can cause polio, for example. But from the data reported so far, and from what is known about the disease, fears of contracting shingles from the shingles vaccine are misplaced.

Like any medical intervention we can think of, the shingles vaccine is a balancing act. The cost and any lingering questions about safety need to be weighed against the benefit: a 50-50 chance that it will keep you from getting shingles and 66% chance that it will prevent postherpetic neuralgia. It's not pleasant, but most people get through shingles just fine. Postherpetic neuralgia is another story: it can last for months, even years, and be quite debilitating. Cutting the risk of that happening by two-thirds would tip the balance for some people, but maybe not others.

Dormant no more

The medical term for shingles is herpes zoster, which is often shortened to just zoster. It's caused by the varicella-zoster virus, the same virus that causes chickenpox. After a case of chickenpox is over, the varicella-zoster virus can lie dormant in the nerves that carry sensory signals (touch, pain, and so on) to the spinal cord and brain. Shingles occurs when the virus re-emerges, like Greeks from the Trojan horse, and becomes active again. Nerves, skin, and other nearby tissues get inflamed. More serious damage to nerve tissue leads to the long-lasting pain of postherpetic (after herpes) neuralgia (the term for pain along the course of a nerve.)

A healthy immune system (particularly the T cells) seems to keep the varicella-zoster virus in check, so conditions and treatments that weaken the system are associated with shingles. For example, people with Hodgkin's disease, a cancer that affects the infection-fighting lymph system, are vulnerable to getting shingles, as are those infected with the human immunodeficiency virus (HIV). A few studies suggest that shingles occurs more often during the summer, so some have proposed a possible link to ultraviolet light.

Your Guide to Shingles