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This page has been updated. This page will automatically redirect to the new site or click the following link to go there now: http://www.bellaireneurology.com/neuropathic_pain/post_herpetic.html
One of the most exciting developments in the neuropathic pain field
is the development of a vaccine for Varicella Zoster. This vaccine essentially
prevents the development of shingles by boosting the body's immune system
to the Zoster virus. The information for this article is from the New
England Journal of Medicine article "A Vaccine to Prevent Herpes Zoster
and Postherpetic Neuralgia in Older Adults" N Engl J Med 352:22 pp. 2271-2284.
The purpose of this article (like the rest of this site) is to put these
findings in perspective and in layman terms.
The shingles represents a reoccurence of the herpes zoster virus or
chicken pox virus which was not completely eradicated during childhood.
The reoccurence rate increases as one gets older. Therefore, in this
study, persons older than 60 were randomized to receive either the varicella
zoster vaccine (VZV) or placebo. Subjects were followed an average of
3.12 years.
The placebo group gives insight into the natural history of the shingles.
The chance of getting shingles was found to be about 1.1% each year.
Those over 70 were only about 10% more likely to get shingles than those
between
60 and 70. A total of 642 subjects in the placebo group got the shingles.
Unlike traditional care, all of these patients were instructed what to
look for in case they got a rash. They were quickly seen and started
on famvir. Because of this prompt treatment, the incidence of post-herpetic
neuralgia was extremely low. Post-herpetic neuralgia is typically defined
as pain beyond 90 days which was only 80 of the initial 642 patients
or about 12%. This is much less than one would expect and probably represents
early treatment with Famvir. Of note, only 33 patients had pain 6 months
after the initial outbreak so the effect of the famvir appears to be
to prevent 95% of long term post-herpetic neuralgia.
The vaccine treated group did even better than the placebo group. The
chance of getting the shingles was less than 1/2 of the placebo group
or about 1 patient per every 200 vaccinated individuals. The vaccine
appears to be more effective in the 60-69 year old group (65% effective)
versus those over the age of 70 (55% effective). Just as impressive,
of the 315 patients in the vaccine group who developed the shingles,
only 27 (9%) developed post-herpetic neuralgia and only 9 (3%) had long
term (> 6 months) of post-herpetic neuralgia. Therefore, not only did
the vaccine prevent a high percentage of cases, those who did get the
shingles were less likely to develop painful complications.
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