NIAID Opens First AIDS Vaccine Trial in Africa

Page 3 of 4

researchers will look for immune responses to clades A and D, as well as
clade B viruses, because the former two subtypes cause most HIV infections
in Uganda.
Recent experiments have revealed that CTLs taken from people naturally
infected with clade A or D viruses can recognize ciade S viruses in the
laboratory. This is known as cross-reactivity.
"Although laboratory data suggest that some vaccines such as this canarypox
vaccine stimulate broadly reactive CTLs, this needs to be evaluated in human
clinical trials," says Margaret Johnston, Ph.D.,, assistant director for
HIV/AIDS vaccines at NIAID and associate director of the vaccine and
prevention research program in NIAID's Division of AIDS.
"If the answer is yes, and the levels of cross-reactivity in most volunteers
are significant, then Uganda and its partners can consider moving this
vaccine into larger trials," adds Dr. Johnston. "If not, we will need to
more strongly encourage development of vaccines based on viruses circulating
in different countries."
*THE URGENT NEED FOR HIV VACCINE RESEARCH IN AFRICA**
Notably, this study represents the first systematic test of any HIV vaccine
in an African population. One of the urgent needs in HIV vaccine research,
says Dr. Johnston, is to understand how human differences influence the
immune response to candidate vaccines. The outcome of this study, she says,
will guide NIAID's future HIV vaccine strategy and is an important step in a
long process toward developing safe and effective HIV vaccines for worldwide
use.
Today, Uganda's population numbers 20 million. According to Dr. Kiyonga,
the rates of H IV infection range from 4 to 10 percent in rural areas to
between 10 and 25 percent in urban locales. Nearly half a million Ugandans
have already died of AIDS. As is true in all of Africa, the disease is
primarily passed from person-to-person through heterosexual sex. A
devastating consequence has been the 1 million orphaned Ugandan children.
In addition to NIAID and the government of Uganda, organizations involved in
facilitating the trial include Makerere University; the Joint Clinic
Research Center; the Uganda Virus Research institute; UNAIDS; Case Western
Reserve University; the Fogarty international Center of the National
institutes of Health; and Pasteur M~rieux Connaught.
NIAID is a component of the National Institutes of Health (NiH). NiAiD
conducts and supports research to prevent, diagnose and treat illnesses such
as HIV disease and other sexually transmitted diseases, tuberculosis,
malaria, asthma and allergies. NiH is an agency of the U.S. Department of
Health and Human Services.

Press releases, fact sheets and other NIAID-related materials are available
2/8/99