Emory
University Will Conduct Clinical Trial of Anthrax Vaccine Regimen
Emory University
is one of five sites nationwide selected by the Centers for Disease
Control and Prevention (CDC) to conduct a clinical trial of an anthrax
vaccination regimen. The study, which is now enrolling volunteers, will
use the anthrax vaccine licensed by the U.S. Food and Drug Administration
(FDA) in 1970. The new trial is designed to test whether changing the
injection method from subcutaneous (under the skin) to the muscle or
decreasing the number of doses affects the quality of the immune response
or local reactions to the vaccine.
Harry Keyserling, M.D., professor
of pediatric infectious diseases at Emory University School of Medicine,
is principal investigator for the Emory study. Other sites include Baylor
College of Medicine; the Mayo Clinic; the University of Alabama at Birmingham;
and Walter Reed Army Medical Center.
Anthrax is a disease caused
by the Bacillus anthracis germ, and most often is found in cattle and
sheep. Infection with anthrax bacteria may cause skin sores and intestinal
or lung illness. Intestinal or lung illness is often serious and may
be fatal. Individuals become infected with anthrax when they eat or
touch animal parts that contain the bacteria or when they eat, touch
or breathe bacteria in the air or on the ground.
The last human clinical trials
of the anthrax vaccine were conducted in the 1950s in goat mill workers
and in the laboratory scientists who studied anthrax. In 1991, with
the threat of Iraqi bioweapons during the Persian Gulf War, the US military
began vaccinating soldiers headed to the Persian Gulf. A shortage of
vaccine and an exhaustive vaccination schedule that stretched over several
years required many soldiers to complete their anthrax immunizations
on the battlefield. In 1998, after assessing the threat of biological
weapons, the Department of Defense required all U.S. armed forces to
receive the anthrax vaccine. More than two million people, mostly in
the military, have been immunized since FDA approval of the vaccine
in 1970. Currently the vaccine is recommended for those in the military
who may be exposed to germ warfare and for scientists who work with
anthrax in the laboratory.
The current FDA-approved
course for the anthrax vaccine requires an initial dose followed by
injections after two weeks, four weeks, six months, twelve months, eighteeen
months, and a yearly booster thereafter. These injections are given
subcutaneously. Some vaccine recipients have experienced pain and swelling
in the arm where the vaccine was given, and investigators believe this
local reaction might be avoided if the vaccine is given in the muscle
of the arm. In 2000, the U.S. Congress asked the CDC to study the method
of injection for the vaccine and the number of doses required.
Participants in the new clinical
trial will be randomly placed in one of six study groups to be vaccinated
over 43 months. One group will receive the licensed regimen of eight
vaccinations under the skin. Another group will receive eight vaccinations
of a placebo, which will be saltwater shots. The remaining groups will
be vaccinated in the muscle rather than under the skin and will receive
fewer vaccine doses. Blood will be drawn following each vaccination
to evaluate the protective immune response. No live anthrax bacteria
will be used in the study. The vaccine does not contain the whole anthrax
germ and cannot cause an anthrax infection.
Nationwide, a total of 1,560
volunteers will be enrolled in the clinical trial. Emory will enroll
approximately 200 of these volunteers. Participants must be 18 to 61
years of age and must not have any major health problems. The study
will require 25 visits over 43 months. At each visit, participants will
either receive a shot, have an investigator look at the shot site, or
have blood drawn. Participants will not know which study group they
are in until the end of the study. All laboratory tests will be provided
free, and participants will receive compensation for each visit.
"The anthrax vaccine has
an excellent safety record," says Dr. Keyserling. "We hope this new
study will simplify the existing dosing and shot regimen for the vaccine
and provide more data to convince an anxious public that the vaccine
is safe."
For additional information
about the study, call Dr. Keyserling's research staff at 404-727-4044.
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