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Gamma Project Newsletter
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The Gamma Project Newsletter is produced bi-annualy by
The Australian Bisexual Men's Association Incorporated.
Editor: Bill Palmer
October 2009 Edition
From the Editor's Desk
In this edition of the newsletter we look once again at issues related
to the prevention and management of HIV from a scientific rather than a
sociological viewpoint. There have been a number of important developments
since I last wrote on this topic this time last year. Then I reported on
the failure of a vaccination program for HIV, this year I can report on some
limited success. There have also been some developments in our understanding
of the relationship between HIV viral blood levels and infectivity during
sexual activity. Circumcision as a preventive measure is also discussed as
well as the link between HIV infection and depression in gay men.
.
The next edition of the Gamma Project
Newsletter will appear at the end of April 2010
Bill Palmer
The Franklin Centre
1B, Hamilton Street,
Mont Albert. Vic.
Australia 3127
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HIV Vaccine Trial
A HIV vaccine has been shown for the first time to cut the risk of infection
what has
been described as a "breakthrough" in the management of HIV transmission.
The vaccine reduced the chance of being infected by almost a third in the
world's largest
vaccine trial carried out by the US Army and Thailand's Ministry
of Public Health. More
than 16,000 volunteers in Thailand participated in the study.
"It is the first demonstration that a vaccine against HIV can protect against
infection,"
Colonel Jerome Kim of the US military HIV research program told a news
conference in
Bangkok. "This is a very important scientific advance and gives us hope
that a globally
effective vaccine may be possible in the future," he said. Thai Public
Health Minister
Witthaya Kaewparadai said the "outcome of this study is a scientific breakthrough".
The vaccine was a combination of two previous vaccines which had not reduced
infection
on their own, and the researchers said they were now studying why the two
vaccines
apparently worked together. The study combined the canarypox vaccine ALVAC,
manufactured by Sanofi-Aventis of France, and AIDSVAX, originally made
by VaxGen
Inc and now licensed to Global Solutions for Infectious Diseases.
The results are especially welcome after scientists were forced in 2007
to abandon two
advanced clinical trials of a vaccine by pharmaceutical company Merck after
it appeared
to actually heighten the risk of AIDS infection. Out of 50 candidates that
have been
evaluated on humans, only two vaccines have made it through all three phases
of trials,
and both were failures. About 30 vaccines remain in the pipeline.
Researchers said the latest vaccine showed a 31.2 per cent efficacy in
reducing the risk of
HIV infection."The outcome represents a breakthrough in HIV vaccine development
because for the
first time ever there is evidence that HIV vaccine has preventative efficacy,"
said the
research team in a statement. The vaccine was tested on volunteers - all
HIV-negative
men and women aged from 18 to 30 - at average risk of infection in two
Thai provinces
near Bangkok starting in October 2003. Half received the vaccine and the
rest were given
a placebo. Out of the placebo recipients 74 of 8,198 became infected compared
with 51 of
8,197 who got the vaccine.
The World Health Organisation and the Joint UN Program on HIV/AIDS congratulated
the researchers for the "encouraging" results. "The study results, representing
a significant
scientific advance, are the first demonstration that a vaccine can prevent
HIV infection in
a general adult population and are of great importance," they said in a
statement. Further
studies were needed to determine if the vaccine has the same effect in
other parts of the
world.
Sanofi Pasteur, the vaccines division of Sanofi-Aventis, said the results,
although
"modest", were the first concrete demonstration that a vaccine "could one
day become a
reality". The Global HIV Vaccine Enterprise, an alliance of researchers,
funders,
policymakers and advocates that includes the Bill and Melinda Gates Foundation,
said it
was a "historic day in the 26-year quest to develop an AIDS vaccine". The
International
AIDS Vaccine Initiative (IAVI), an organisation that promotes the search
for a vaccine,
said the trial results were "very exciting and a significant scientific
achievement".
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Antiretroviral Treatment As A Preventice Measure
An article by Michael Carter in the June 2009 edition of poslink, issue
45, looks at the
potential for treatment of patients with HIV to stop the spread of the
virus. In addition to
reducing viral load in the blood, treatment will also reduce the viral
load in genital fluid
which will in turn reduce the risk of sexual transmission. Some Swedish
HIV physicians
have stated that people who have been taking treatment for 6 months, who
adhere to the
treatment, and who do not have any sexually transmitted infection are never
infectious to
their heterosexual partners. This is supported by research that showed
there were no HIV
transmissions in heterosexual couples when the amount of virus in blood
fell below a
certain level.
The potential for treatment to reduce the spread of the virus is widely
recognised but not
everyone agrees that reduced viral loads in blood are a reliable indicator
of infectivity.
There are apparent cases of transmission even when a person has an undetectable
level of virus in blood. .
However such cases do not occur frequently and it is believed that reducing
the viral load in blood
to undetectable levels can reduce the risk of HIV transmission to the same
degree as the
use of condoms. However as the author points out, condoms remain central
to the
management of HIV transmission. It is also the case that a concurrent sexually
transmitted infection will increase the viral load in genital fluid and
therefore the risk of
infection occuring.
The potential for at least reducing the rate of infection is apparent from
the data presented
and as a result in some places treatment of the virus has been suggested
as a prevention
measure. There has been significant debate about the benefits of instituting
treatment
early and at higher viral loads and there is a body of evidence that this
measure can
protect the immune system of the patient better than treatment at the current
recommended levels. Clearly there is a case to be made for early and effective
treatment
both from the view of patient benefit and reduction in transmission.
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HIV and Depression
In the June 2009 edition of Positive Living there was an interesting article
which looked
at the link between HIV infection and depression. The research involved
interviews with
General Practitioners and their patients, both HIV positive men and
HIV negative men
who attended general practice clinics with high HIV caseloads. The research
confirmed
that there is a very high rate of depression among gay men. Thirty percent
of HIV positive
men experienced depression compared with twenty percent of HIV negative
men.
Multiple causes were suggested for depression which included discrimination,
marginalisation, personal withdrawal and socio-economic hardship. Other
factors for
positive men were loss of relationships, social connection and career and
earning
capacity. Certain key events were cited by General Practitioners as likely
to increase their
vigilance and awareness of depression. These included the need to undertake
therapy, an
AIDS defining illness and treatment failure. This was accentuated in those
men who had
been living with HIV for long periods of time.
One outcome of the study has been the development of a module to assist
gay men in self
managing their depresseion as well as a fact sheet on managing the sexual
side effects of
depression. This module is available on the Climate GP website. The module
consists of
six lessons and is said to be easy to follow. While no results are as yet
available from this
particular module a similar program for heterosexual people has been shown
to be
effective. Anyone interested in accessing this resource should consult
their doctor.
In the same publication there is also an article on sexual dysfunction
in HIV positive gay
men. This is often associated with depression. The use of antidepressants
and poor coping
strategies were cited as causitive factors. The study found that almost
half the positive gay
men in Australia reported multiple sexual problems which included loss
of libido, erectile
dysfunction and inability to ejaculate.
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Circumcision As a Preventive
Measure
There is a report in the August 2009 edition of "poslink" of a randomized
controlled trial
which found the male circumcision did not reduce the transmission of HIV
to their female
partners. In a study where half of a group of 922 men were circumcised
while the others
acted as controls. The rate of transmission to female partners of the men
was not reduced
and the study which was intended to run for a two year period was ended
early.
This is in stark contrast to the impact of circumcision on female to male
transmission.
The article reports that the benefit in reducing the risk of transmission
to men is
significant, longer term studies find that the reduction in female to male
transmission is
greater than first thought, reduction in infection of the order of 65%
are reported in this
article.
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