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June 6, 2010)
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ANI Wednesday, June 2,
2010 19:39
A team led by Scripps
Research Institute scientists has determined the structure of an immune system
antibody molecule that effectively acts against most strains of human
immunodeficiency virus (HIV), the virus that causes AIDS.
Published in an advance, online issue of the journal Proceedings of the National
Academy of Sciences (PNAS) during the week of June 1, 2010, the study
illuminates an unusual human antibody called PG16.
"This study advances the overall goal of how to design an HIV
vaccine," said Scripps Research Professor Ian Wilson, who led the team with
Dennis Burton, Scripps Research professor and scientific director of the
International AIDS Vaccine Initiative (IAVI)
According to the World Health Organization's latest statistics, around 33
million people are living with HIV worldwide. During 2008 alone, more than 2
million men, women, and children succumbed to the disease and an estimated 2.7
million were infected with HIV.
One of the most compelling medical challenges today is to develop a vaccine that
will provide complete protection to someone who is later exposed to this virus.
HIV causes AIDS by binding to, entering, and ultimately leading to the death of
T helper cells, which are immune cells that are necessary to fight off
infections by common bacteria and other pathogens. As HIV depletes the body of T
helper cells, common pathogens can become potentially lethal.
An effective HIV vaccine would induce antibodies (specialized immune system
molecules) against the virus prior to exposure to the virus. Also called
immunoglobulins, these antibodies would circulate through the blood, and track
down and kill the virus.
June 4, 2010 By Tracy
Staton
Call it another
trickle-down effect of the Great Recession. Gilead Sciences
says it's launching new discounts and an extended pricing freeze on its
HIV meds to combat budget shortfalls in AIDS assistance programs across the
country.
As of last month, there
were more than 1,100 patients on AIDS assistance waiting lists in 10 states--and
those lists have grown by a factor of 10 over the past year, according to the
San Jose Business Journal. Just 99 individuals stood in the same queue in May
2009. Plus, 16 states have tightened access to drug-purchasing assistance by
cutting drugs from their formularies, limiting spending on AIDS meds, and
tightening up eligibility based on income.
So here's what
Several drugmakers have
expanded their patient assistance programs in the face of economic woes around
the world. Pfizer, for one, instituted a "free meds" program for those
who've lost their jobs. GlaxoSmithKline has offered free vaccines to uninsured
patients, and it's giving 50 percent discounts to patients who don't have
prescription drug coverage.
05 June 2010
IT took 105 years for
researchers to develop a vaccine against the deadly typhoid disease and 89 to
get one against polio.
This is what Mitchell Warren, the executive director of the AIDS Vaccine
Advocacy Coalition (AVAC) often tells anxious prevention advocates seeking
answers to why it has taken so long to come up with an HIV vaccine.
She has always been an optimist in the face of adversity.
“For years now researchers and scientists have been working hard to develop an
HIV vaccine but this is a very involving process, it takes years of hard work,
disappointments and starting all over again but we will eventually get there,”
“When you look at other diseases and the time between discovery of
microbiologic cause of that disease and development of the vaccine you can see
that a vaccine cannot be developed overnight otherwise you will have a product
on the market that will do more harm than good for people.
“There are numerous checks and balances, we all have to be patient but while
scientists and researchers develop a vaccine those living with HIV must be given
the right care and treatment.”
For the first time, this year the world commemorated HIV Vaccine Awareness Day
on May 18 which came at a time results from clinical trials have shown that an
Aids vaccine is possible.
The evidence came from the world’s largest vaccine trial that was conducted in
The results showed that an experimental Aids vaccine could lower the risk of HIV
infection by about 30%.
Although not enough to allow for registration of the vaccine,
“Despite the many perspectives on and interpretations of the trial — and its
results — the Thai Aids vaccine trial provides evidence for the first time
that it is possible to reduce the risk of HIV infection with a vaccine,” said
“In fact, there’s renewed energy in the Aids vaccine field today, even as we
grapple with what these results mean and where we go from here.
“The next steps for the field must involve more not less: more trials, more
community volunteerism, more political will and sustained funding.
“One way to help ensure this is to celebrate what has happened to date, even
as we prepare for everything that still needs to be done.”
Zimbabwe AVAC/Global Campaign for Microbicides prevention research fellow
Munyaradzi Chimwara agreed that there is need for more funding for the field of
prevention research such as the development of a vaccine and microbicides.
“It may appear as though we are running out of time in developing an HIV
vaccine or microbicides that work but if we look at how research is done, it is
very taxing and there are checks and balances that are meant to protect you and
me,” said Chimwara.
“When you look at the time frames of the development of vaccines you can see
that the shortest took 23 years while the longest over a century, so HIV
research is very demanding.
“Sometimes even after taking that long results may not be encouraging but
donors and funders should not tire because developing a vaccine or microbicide
will in the long run cut down money spent on HIV prevention and treatment.”
Founded in 1995, AVAC is an international non-profit organisation that uses
education, policy analysis, advocacy, and community mobilisation to accelerate
the ethical development and eventual global delivery of Aids vaccines and other
new HIV prevention options as part of a comprehensive response to the pandemic.
BY BERTHA SHOKO
Jun 1, 2010
NEW DELHI
: The HIV virus is unique and requires equally
novel interventions. Scientists are, therefore, working on various
out-of-the-box drug delivery systems to protect women against HIV.
Imagine a cellotape-like film that once inserted in the vagina would melt away
and disperse drug to cells to protect against HIV. Or maybe a flexible vaginal
ring containing two anti-HIV drugs. How about an almond-shaped vaginal tablet
that would dissolve and deliver sustained levels of anti-HIV drugs over several
hours.
All these products have now passed initial trials, according to scientists who
presented their early findings at the International Microbicides Conference in
Most of the world's women do not control when, with whom and with what
protection, if any, they have sexual relations. This powerlessness is most acute
in developing countries where HIV prevalence is highest. Women's most urgent
need is for a prevention technology which they control themselves.
In the absence of a vaccine against HIV, microbicides are the answer —
chemical agents used typically by women within the vagina in order to prevent
infection by HIV.
However, most of the research on microbicides till now has focused on gels or
vaginal creams. But the world has failed to create a successful microbicide. In
February 2007, trials of a cellulose sulphate called Ushercell was stopped ahead
of schedule for failing to work. In 2008, Carraguard, a vaginal cream that was
the first to make it through late-stage testing, failed. It was unable to
prevent transmission of the virus.
Michael Carter, May 31,
2010
The fat loss that can be
caused by some anti-HIV drugs appears to persist in the long term despite
discontinuation of the drugs that cause it, US investigators report in a study
published in the online edition of AIDS.
Researchers from the prospective Fat Redistribution and Metabolic Change in HIV
Infection (FRAM) study found that significant differences in fat distribution
were evident between HIV-positive patients and HIV-negative controls and
persisted over the five years of the study.
Stopping d4T (stavudine, Zerit), the anti-HIV drug most associated with fat
loss, was associated with only modest gains in limb fat.
Soon after it was introduced, combination antiretroviral therapy became
associated with changes in body-fat distribution and metabolic alterations
associated with a long-term risk of cardiovascular disease. This syndrome of
side-effects is called lipodystrophy.
Fat gain around the abdomen (visceral adiposity) and fat loss from the limbs and
face (lipoatrophy) were observed in some patients. Protease inhibitors were
originally thought to be the cause, but it became apparent that a major cause of
fat loss was the mitochondrial toxicity caused by some nucleoside reverse
transcriptase inhibitors (NRTIs), especially d4T, and – to a lesser extent –
AZT (zidovudine, Retrovir, also in the combination pills Combivir and Trizivir).
Stopping or changing HIV treatment became an established strategy for treating
lipodystrophy.
A lot of research has been undertaken in lipodystrophy, one of the major
projects being the FRAM study.
In this study, investigators used MRI scans to compare the body-fat distribution
of HIV-positive patients and HIV-negative controls. Their initial analysis found
that patients with HIV had significantly lower levels of subcutaneous fat than
their HIV-negative peers.
The investigators wished to see if these differences persisted in the long term.
They therefore repeated their analysis after five years of follow-up.
Their study population included 477 HIV-positive patients and 211 HIV-negative
controls. Their characteristics were well matched; however, the HIV-positive
patients were more likely to be male (68% vs 53%).
In the first analysis, and then five years later, the HIV-positive patients had
significantly lower levels of fat in all the body areas which were measured.
The investigators found that those with HIV were more likely than the controls
to lose both subcutaneous fat (35% vs 27%, p = 0.0013) and visceral fat (17% vs
5%, p < 0.0001).
At baseline, 48% of HIV-positive patients had fat loss, and this had increased
to 53% after five years.
Of the HIV-positive patients diagnosed with lipoatrophy at baseline, 82% still
had fat loss five years later.
The baseline analysis showed that the mean limb-fat level of HIV-positive men
was 67% of that seen in the controls. This difference persisted in the long
term, with HIV-positive men having only two-thirds (65%) of the limb fat seen in
their HIV-negative peers.
Limb-fat levels were also lower in HIV-positive women at both the initial
assessment and at follow-up (83% and 77%).
Discontinuing treatment with d4T, the drug most associated with fat loss, had
little long-term impact on limb-fat gain. Patients who adopted this strategy
experienced an average annual increase of fat in the leg of only 1%.
“Likewise”, write the investigators, “little gain was associated with
discontinuation of AZT or other antiretroviral drugs.”
The investigators conclude that “there is no relative recovery from
lipoatrophy when HIV-infected participants are compared to controls.”
They add, “these data must be considered when studying the potential
mechanisms underlying HIV-associated lipodystrophy. It remains to be determined
whether there was destruction of adipose cells and precursors…or whether other
factors continue to contribute to the persistence of lipoatrophy in HIV
infection.”
Reference
Grunfeld C et al. Regional adipose tissue measured by MRI over 5 years in
HIV-infected and control participants indicates persistence of HIV-associated
lipoatrophy. AIDS 24: online edition, DOI: 10. 1097/QAD.0b013e32833ac7a2, 2010.
A patient who tested
positive for extreme drug resistant tuberculosis (XDR-TB) awaits treatment at a
rural hospital at Tugela Ferry in
Credit: Reuters/Mike
Hutchings