EMORY UNIVERSITY SCIENTISTS JOIN WITH NOVAVAX, INC. IN NIH-FUNDED
HIV VACCINE DESIGN AND DEVELOPMENT TEAM
Scientists from Emory School of Medicine and Emory Vaccine Center
Will Develop HIV Vaccine Made from Virus-Like Particles (VLPs)
ATLANTA – The National Institutes of Health (NIH) has awarded
a $19 million, five-year grant for HIV vaccine development grant to
Novavax, Inc., along with partners at Emory University School of Medicine
and the Emory Vaccine Center, Tulane University, and the University
of Pittsburgh. The award is part of the National Institute of Allergy
and Infectious Disease (NIAID) Vaccine Design and Development Teams
program. The Emory team of researchers includes Richard W. Compans,
PhD, professor and chair of microbiology and immunology and faculty
members Sang-Moo Kang, PhD, Andrei N. Vzorov, PhD, and Chinglai Yang,
Scientists at Emory and Novavax, Inc., including Robin A. Robinson,
PhD, director of Novavax’s Vaccine Division and principal investigator
for the grant, are developing and testing a novel virus-like particle
(VLP) vaccine. The genes that encode the main structural proteins of
HIV (the envelope and gag core proteins) will first be expressed in
insect or mammalian cells. These proteins self-assemble to form VLPs,
which are devoid of the virus genes themselves, and will be purified
to form the vaccine. The investigators propose to deliver this protein-based
vaccine in a manner that they predict will induce broad neutralizing
antibodies against HIV in blood and mucosal tissues. The HIV genes for
initial testing of the vaccine were taken from HIV strains in circulation
in the United States. In subsequent studies the investigators will use
genes from other geographic regions in similar approaches.
Most scientists agree that a successful AIDS vaccine should induce both
antibody and cell-mediated immune responses. The Emory group has successfully
constructed HIV virus-like particles (VLPs) that have been shown to
induce both antibody responses and cellular immune responses in animals,
including mice and monkeys. In this project, novel strategies will be
developed for production of HIV VLPs with enhanced immunogenicity to
test their effectiveness in inducing immune responses.
"The use of VLPs for immunization has several advantages," notes Dr.
Compans. "The nonreplicative nature of VLPs and their lack of viral
genomic RNA make them safe for broad and repeated application. Since
the assembly and arrangement of components in VLPs resembles that of
the virus, they may be more effective in inducing neutralizing antibodies.
Furthermore, VLPs are less likely to undergo aberrant events during
purification that would alter their native properties."
Many other vaccine approaches elicit immune response against other components
present in the vaccine, Dr. Compans says, which may limit the possibility
of boosting immunity by repeated administration. In contrast, the VLP
vaccine contains only HIV antigens, and can thus be administered repeatedly
to boost immune responses. Thus, VLP vaccines provide a promising new
approach for the development of a highly effective HIV vaccine with
a high degree of safety.