PROCAARE: Vaccine Trials (02)

[procaare@usa.healthnet.org]

[See archive 970924205113 for initial RFI. - Mod.]

Regarding the testing of candidate HIV vaccines in human trials, here are
a
few brief comments.

There has been over 20 candidate PREVENTIVE vaccines tested in small phase
I trials for safety and biological effects, in the U.S. and Europe mostly,
with a few trials in China, Israel, Cuba.  These vaccines have been based
on several different designs including:

        recombinant proteins:  based on the HIV envelope, and, more
recently on the internal p24 protein
        peptides:  portions of proteins produced synthetically
        recombinant viral vectors:  vaccinia and canarypox viruses
genetically engineered to express one of more HIV proteins
        DNA vaccines:  "naked" pieces of DNA designed to express one or
more HIV proteins when taken up by cells.
Other designs are being studied in laboratory and animal experiments.

The design that is furthest along in testing is referred to as
"prime-boost" and is a combination of two vaccines - a recombinant
canarypox expressing HIV env,gag,pro to prime the immune response and
elicit cellular immune responses, followed by boosts with recombinant HIV
envelope (gp120).  Prime-boost recently entered a phase II trial in the
U.S. which will evaluate safety and biological activity in several hundred
volunteers, including many at risk for HIV infection.

To date, no vaccine candidate has been evaluated in larger trials designed
to evaluate their efficacy.

This past week, much press was given to a group of physicians in the
U.S.who are recruiting others to participate in a trial of a
live-attenuated HIV design.  The hope is that this design will be
protective (as it has been in animal models of AIDS), yet not cause
disease because several important genes have been genetically removed from
the HIV.
   However, there is no "product" ready to test and no company has
committed to producing this vaccine because it is considered too risky.
The International AIDS Vaccine Initiative is working with several groups
to
try to obtain additional animal data so that the possible risks can be
better evaluated against the possible benefits.

For more information on the International AIDS Vaccine Initiative, go to
http://www.iavi.org;  or write to:

        The International AIDS Vaccine Intiative
        810 Seventh Avenue,
        New York, NY 10019.  USA

For those who wish to stay informed, IAVI publishes a newsletter on HIV
vaccine R&D - The IAVI Report, which is available by mail, and will soon
be available on the webb site.

Margaret (Peggy) Johnston, Ph.D.
Scientific Director
International AIDS Vaccine Initiative
1400 I Street NW  Suite 1220
Washington, DC   20005
phone 202 842 3004
fax 202 408 1818
e-mail  103645.1720@compuserve.com

KEYWORDS:  Prevention, Vaccine, Live, Attenuated, Clinical Trial
......................................................................gjn

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