The shingles vaccine
Posted by medconsumers on May 17, 2010
By the time age 60 rolls around, everyone knows at least several people who’ve suffered a painful attack of shingles, aka herpes zoster, and its severe complication called postherpetic neuralgia. Consequently, there’s a growing interest in the relatively new shingles vaccine, especially now that this expensive shot is covered by all Medicare part D health plans. The vaccine has been available for several years because it has been proven effective. Its long-term safety, however, has been in question—that is, until now. A newly published safety study that followed vaccinated people more than three years indicates that the vaccine does not cause severe adverse reactions.
First, a retrospective look at what has already been proven in terms of effectiveness. Contrary to what people might expect from this vaccine, it reduces—but does not eliminate—the chance of getting herpes zoster. A large 2005 trial, called The Shingles Prevention Study, randomly assigned about 18,000 people to receive the shingles vaccine and another 18,000 received a placebo vaccine. All participants were over the age of 60.
After three years of follow-up, there were 315 cases of herpes zoster among vaccine recipients and 642 among placebo recipients. As for postherpetic neuralgia, the much-dreaded complication, there were 27 cases among vaccine recipients and 80 among placebo recipients. Of the vaccinated people who developed postherpetic neuralgia, their pain was greatly reduced (by 61%) in comparison to the placebo-vaccinated people who developed this complication.
Now for the recently published safety study. It’s an offshoot of The Shingles Prevention Study, which had singled out the study participants who suffered a serious adverse reaction. After three years of follow-up, this turned out to be exactly the same percentage (1.4%) of the vaccinated and of the placebo groups. The researchers also looked at deaths and hospitalizations and found no difference between the two groups. The less serious side effect of pain and swelling around the injection site was more common in the people who received the shingles vaccine. These results were published in the current issue of Annals of Internal Medicine. The authors identified this limitation of their study, “Confirmation of reported serious adverse events with medical record data was not always obtained.”
Should you get the vaccine?
Shingles can be an extremely painful and debilitating blistering rash that increases in severity with increasing age. The frequency and severity of postherpetic neuralgia also increases with age. The pain and discomfort of postherpetic neuralgia can be prolonged (months, even years) and disabling. We all have a lifetime risk of 20-30% of getting herpes Zoster. That’s if we live to be 80. After that, the risk rises to 50%.
Because the vaccine is expensive (more than $200) and requires refrigeration, many doctors do not want to invest in a supply. Most prefer to write prescription for their patients who must purchase the vaccine at the local pharmacy. The vaccine must be administered within a half hour of purchase. Pretty inconvenient all around.
One additional note of caution regarding FDA and CDC safety requirements, which leave much to be desired:
The Shingles Vaccine Study initially followed its participants for only 42 days. This is all that was required by the Food & Drug Administration to be declared safe. (Zostavax, Merck’s vaccine was the first shingles vaccine to be approved.) The Centers for Disease Control and Prevention has recommended the shingles vaccine for all people over the age of 60 ever since 2008 (when it replaced a CDC provisional 2006 recommendation), though the three-year data on safety only became available this month. Whether this provides sufficient long-term safety information is unknown.
People who should not get this vaccine include those whose immune systems are not working properly, for example, people with AIDS. For more about contraindications, click here
Maryann Napoli, Center for Medical Consumers©