A vaccine for shingles
Doctors know it as zoster, but up to a million Americans are stricken
each year by the infection they call shingles. By either name, it’s
an unsightly, often painful process that can be prevented by a vaccine
that was approved in 2006.
The culprit is varicella-zoster virus (VZV), the same virus
that causes chickenpox (varicella in children). The vast majority of
children recover completely, but that’s not the end of the story.
Instead of being killed and eliminated from the body, VZV goes into hibernation,
hiding out in the part of the nervous system known as the sensory
nerve ganglia. In most people, the virus remains dormant and harmless
for life, but in up to 15%, VZV becomes active and causes shingles.
Most patients with shingles are older than 60, and some have weakened
immune systems. The virus spreads along the sensory nerve to form a line
of blisters on one side of the body. Most patients recover fully, but
a few develop serious complications, and up to a third develop long-lasting
pain (post-herpetic neuralgia). Antiviral medicines, which are
often prescribed with steroids, can reduce the risk of pain.
Chickenpox has become rare in American children, thanks to the varicella
vaccine that was licensed in 1995. But 90% of American adults had chickenpox
as children, and all of them are at risk for shingles.
Enter the new vaccine. It is similar to the pediatric varicella vaccine,
but it contains a much larger dose of the weakened VZV virus than the
chickenpox vaccine does.
A major 2005 trial in 38,546 adults age 60 and older found the vaccine
safe and effective. It reduced the incidence of shingles by more than
51%, and it lowered the risk of persistent pain by more than 66%. The
most common side effect was pain at the injection site, which was usually
The new vaccine, Zostavax, is suggested for people age 60 and older
but should not be given to those who have immune systems that have been
weakened by certain malignancies, therapy with steroids or other immune-suppressing
medications, or HIV infection. Zostavax must be kept frozen until it
is used, and it is expensive. Doctors don’t yet know how long the
vaccine’s protection will last or if booster shots will be needed.
June 2007 update
Back to Previous Page