NIAID Launches Three New AIDS Vaccine Trials

86/13/95 11:23 HEDIATEL FAX SERVICE->THE JOURNAL SCIENCE/HNIH CORRESPONHDENHT 884, 06/13/95 14:09 '301 496 0019 NIH NEWS-2B25/31 i005/011
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smallpox vaccine, have already been tested in the AVEG. Like vaccinia virus, canarypox virus can
fit large pieces of foreign DNA in its genome, infect human cells and cause them to produce
foreign proteins. Unlike vaccinia, however, canarypox virus does not grow in human cells, which
is an important safety feature.
In addition, although vaccinia-based IVl vaccines and an earlier version of the ALVAC
vaccine contain copies of only one HIV surface protein gene, ALVAC-IV (vCP205) contains
copies of genes for three pieces of HIV--the surface protein, the core protein and one enzyme--
more than any other experimental preventive HIV vaccine tested so far. When the ALVAC
vaccine infects human cells, the cells make proteins from the genes and package the proteins into
HIV-like particles called pseudovirions. Although not infectious, these pseudovirions fool the
immune system and trigger an immune response.
The trial will enroll 76 adults at low risk of HIV infection, half of whom must not have
received a smallpox vaccination, to test if smallpox vaccine changes the immune responses. Each
volunteer will receive between three and five intramuscular injections of ALVAC-HIV (vCP205)
or a placebo over the two-year course of the study. The placebo is an experimental rabies vaccine
(ALVAC-RG) made by a similar process that in other trials appears quite safe. The researchers
and volunteers will not know which product each volunteer received until the study ends.
Two different immunization schedules will be compared: a primary immunization and
boosters at one and six months, or one, three and six months. Another booster at 12 months may
be added.
The study chair for AVEG 022 is Lawrence Corey, M.D., of the University of Washington

in Seattle. All five other AVEG sites--Johns Hopkins University, the University of Rochester
(more)