Date: Mon, 6 Feb 1995 12:06:00 +0500
From: awilson@smtpinet.aspensys.com (Wilson, Anne)
Subject: NIAID News: Progress in HIV Vaccine Development Discussed

N E W S   R E L E A S E
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National Institute of Health
National Institute of Allergies and Infectious Diseases
February 1, 1995

    Progress in HIV Vaccine Development Discussed

      Margaret I. Johnston, Ph.D., acting deputy director of the
Division of AIDS of the National Institute of Allergy and
Infectious Diseases (NIAID), will present a state-of-the-art
lecture on progress in HIV vaccine research and development on
Wednesday, Feb. 1, 1995, at the Second National Conference on Human
Retroviruses and Related Infections in Washington, D.C.
      A vaccine for AIDS is possible, but researchers face a
special combination of scientific challenges that will require the
integration of two strategic approaches, including the simultaneous
evaluation of different vaccine concepts, and a strong and diverse
basic research effort, says Dr. Johnston.  These challenges include
the enormous genetic diversity of HIV, the lack of an ideal animal
model of HIV disease and the absence of a verified state of natural
immunity.
      A rational overall strategy for HIV vaccine development
should evaluate the safety, immunogenicity and potential efficacy
of a range of promising vaccine concepts in animal models and human
Phase I and Phase II trials.  Ultimately, the effectiveness of only
the most promising concepts should be determined in expanded trials
in appropriate uninfected populations at higher risk for HIV
infection.
      Dr. Johnston will provide a summary of current data on
recombinant vaccines based on HIV's gp120 envelope protein and then
focus on other vaccines in or near clinical development, including
pox virus vectors expressing multiple HIV genes and peptide-based
approaches.  Phase I trials testing improved designs of these and
other vaccine concepts could start in the United States in 1995 or
1996, she says, and Phase II human testing in 1996 or 1997.
      Novel vaccine concepts being explored in the laboratory and
animal studies include DNA vaccines, HIV-like particles and subunit
combinations, which could enter Phase I testing soon, according to
Dr. Johnston.
      The second strategic component includes a concerted effort in
basic research targeted toward a number of obstacles facing vaccine
developers.  Dr. Johnston will summarize the knowledge base and
immediate priorities in four critical areas:
      1) Correlates of immunity, to better define the immune
responses desired from an HIV vaccine.  For example, scientists
should intensively study animal models, vaccine trial volunteers
who become infected, HIV-infected people who remain healthy for
many years without losing immune function, and those exposed to HIV
who resist infection.
       2) Animal model development, to identify the best animal
model(s) in which to test vaccine concepts.  Investigators should
more thoroughly examine the dynamics and course of infection in
various animal models to identify those which most closely parallel
human disease.
      3) HIV diversity, to understand and overcome the problems
posed by HIV's genetic variability.  Researchers need to develop
better assay systems, examine the immunologic significance of
genetic diversity, and design approaches to overcome diversity.
      4) Behavioral research, to prepare for efficacy trials.  For
example, scientists should continue to study barriers to
participation in trials, and develop and validate measures of
risk-taking behavior and behavioral change.  These studies are
essential to the design of successful large-scale field trials.
      NIAID, part of the National Institutes of Health, supports
research aimed at preventing, diagnosing and treating such
illnesses as AIDS, tuberculosis and asthma as well as allergies.
NIH is an agency of the U.S. Public Health Service, part of the
U.S. Department of Health and Human Services.