Chicken pox may be an annoying and distressing disease associated with childhood, but if the virus that causes it reactivates in your body later in life, the result can be a much more painful and debilitating condition known as shingles. There is a vaccine formulated to prevent shingles, but how effective is it against this potentially severe affliction?
- Read more: What older people should know about shingles
A single-dose vaccine called Zostavax — a stronger version of the chicken pox vaccine currently given to children — was approved by the US Food and Drug Administration (FDA) in 2006 to prevent (not treat) shingles in adults over the age of 60. In Canada, Zostavax was made available for adults over 60 starting in 2008. In 2011, both the FDA and Health Canada updated their approval of the vaccine to include people between the ages of 50 and 59.
Research on the vaccine: The Shingles Prevention Study was a clinical trial designed to assess the effectiveness of Zostavax in adults over the age of 60. It compared the vaccine with a placebo in more than 38,000 older adults over the age of 60.
Imperfect but valuable The vaccine did not prevent 100% of shingles cases. In fact, it only reduced the incidence of shingles by slightly more than half, or 51%, in all adults over 60 years of age. The severity and duration of short-term symptoms, however, in adults who did get shingles after being vaccinated was much reduced.
- The variation in effectiveness by age group in this study broke down as follows, according to the US Centers for Disease Control and Prevention (CDC):
- 64% effective at preventing shingles in those aged 60-69
- 41% effective in people aged 70-79
- 18% effective in people aged 80 or older
Perhaps more important, however, was that the proportion of people who went on to develop chronic nerve pain called post-herpetic neuralgia (PHN) — the most common and most debilitating complication that can result from shingles — was also reduced by up to two-thirds across the subject population. Since protection against PHN remained strong among adults over the age of 80, for whom complications are typically most severe, the CDC recommend the vaccine for all adults over 60.
Who shouldn't get the shingles vaccine: The shingles vaccine is not recommended for adults with suppressed immune systems, such as those with HIV/AIDS, adults receiving immunosuppressant drugs for cancer, patients with lymphoma or leukemia, or women who are pregnant.
How long does protection last? The Shingles Prevention Study evaluated Zostavax for 4 years past the time of vaccination, and additional research suggests protection against herpes zoster may persist up to 7 years, according to the Public Health Agency of Canada. Further research will determine whether a so-called booster shot may be required for continued protection against shingles in older adults.
CDC Seeks to Protect Older Adults With Shingles Vaccine Message. US Centers for Disease Control and Prevention Public Information Sheet. Accessed July 10, 2013.
Herpes Zoster (shingles) Vaccine. Public Health Agency of Canada Public Information Sheet. Accessed July 10/13.
Marla Shapiro, Brent Kvern, Peter Watson, Lyn Guenther, Janet McElhaney, and Allison McGeer. "Update on Herpes Zoster Vaccination: A Family Practitioner's Guide." Canadian Family Physician October 2011 vol. 57 no. 10 1127-1131.
Statement on the Recommended Use of Herpes Zoster Vaccine. Public Health Agency of Canada Information Sheet. Accessed July 10, 2013.