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August 2002 Public Health Journal Club
Judith King. HIVAN Media Office
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The August session of the Journal Club was devoted to a selection of reportbacks from the AIDS 2002 Conference in Barcelona. Opening the meeting, Victor Daitz Chair of HIV/AIDS Research Prof Jerry Coovadia observed that with the gathering in Barcelona being the largest to date,(with over 14 000 delegates), it had offered researchers a valuable opportunity to share information. South Africa had been well represented at the Conference.
He and a number of intercontinental peers in infant feeding research had formed a collaborative network focusing on the prevention of mother-to-child-transmission. In terms of new science, however, he said that the Barcelona forum had produced few advances in learning that would help to shape responses to the epidemic.
Nonetheless, political prominence had been notable, with spectacularly moving addresses being given in the closing sessions by former Presidents Mandela and Clinton, as well as current heads of State from the Caribbean, Belgium and Germany, who outlined what world leaders should be doing to mitigate the spread of HIV/AIDS.
Epidemiologist Prof Quarraisha Abdool Karim gave the Journal Club an overview of her presentation on the natural history of HIV infection. Commenting generally on the Conference, she said that although the rhetoric had been right, action seemed to be lacking, with no real progress having been made since the AIDS2000 event. She reiterated that in the context of the Barcelona theme ("Knowledge and Commitment for Action"), no scientific paradigm shifts had been evident. She felt that it was time to collate the 20 years of knowledge behind the epidemic and map out sound strategies for the implementation of treatment, prevention and care programmes.
UNAIDS reports had reflected alarmingly rapid increases in emerging epidemics in countries like Russia and China, where substance abuse was proving to be the primary factor driving the spread of HIV infection. Although it was hoped that the tragic scale of sero-prevalence such as that experienced in Africa could be averted, it was disturbing to note the rise in drug abuse amongst children in Russia as young as six years old. The "gay epidemic" has all but disappeared, and no papers on Karposi's sarcoma had been presented, but the vulnerability of women had become much more prominent.
Regarding the interface between science and activism, she believed that all stakeholders present at the Conference had demonstrated a mutually supportive stance and an understanding that HIV/AIDS was a global challenge. Governments were clearly accepting the need for accountability, particularly in relation to human rights and the role of gender inequity in the spread of the epidemic.
Regarding to access to treatment, there had been general recognition that this was non-negotiable and could not be separated from prevention and care. Developing research on microbicides seemed promising, and of further interest had been investigations into the role of the cervix in HIV transmission to women.
Prof Abdool Karim noted that ethical guidelines for biomedical work needed more attention, and applauded the new theoretical frameworks offered by Peter Aggleton and Richard Parker regarding stigma and discrimination. She recommended that those present explore the UNAIDS website for details of Rao Gupta's presentation on a very important model for the integration of gender into HIV/AIDS initiatives, involving a continuum from gender awareness to transformation and empowerment of women.
Dr Fanny Kiepiela reported on the optimism of two vaccine studies with a positive outcome:
The first, involving one-to-six-month trials of a canary-pox from Thailand, measured CD8 counts (cytotoxic T-cells which fight the virus by killing infected cells). At as early as two weeks, immune response activity had been noted, and with a booster administered at six months, a very high level of response was indicated.
The second vaccine study, done in Uganda, demonstrated that cross-clades could be used effectively for vaccinations. It was now known that because different T-cell responses occurred in the various clades specific to different populations, more assessment of each population was required so that a broad, more universal vaccine, eliciting the highest response possible to all sections of the virus, was needed. Longitudinal studies would be very important in this regard, because responses change over time.
In investigations focusing on discordant couples, it had been shown that uninfected partners had higher activity of NK cells (those that kill the virus directly, without antigens) as well as more activated and intact CD4 cells.
Vaccine development was seen as important in the context of the drawbacks of anti-retroviral therapy, i.e. long-term toxicity, difficulties with adherence, the costs of provision and the known side-effects. Studies had shown that although Structured Treatment Interruption (STI) heightened T-cell function, once the virus mutated, this model was ineffective. It had also been shown that the virus mutated even faster than originally thought, as neutralising antibody was greater to early viruses than to later viruses in the same patient.
However, research using microchip technology, whereby microchips had been coated with antigens and encased, using samples with serum or plasma, had been promising. The chips were fitted into detectors with a light reading the CD4 and viral load counts. Multiple tests using small volumes at a cost as low as $3 per dose could prove to be very successful, especially in resource-poor settings.
Community Health specialist Dr Robert Pawinski gave a brief overview of his experiences of the Conference, commenting on Dr Peter Piot's emphasis on the global issues surrounding the epidemic and the need to increase funding for programmes in developing and poor countries. He also noted the research being done on the provision of anti-retroviral therapy to workers and its benefits for improving health and productivity levels, which in turn sustained economies.
Virologist Dr Pravikrishnen Moodley gave a short talk on new drugs in test mode, focusing on viral load work and the STI debate. Two new products had been introduced: the first being Enfurvitide (or T-20) made by Roche-Trimeris, a fusion inhibitor that is administered by subcutaneous injection twice daily. The only side-effect shown was a mild reaction around the injection site. Phase III trials had been completed (the Toro Studies), and resistance had not been shown to be problematic at this stage. The second drug, Tenofovir, made by Gilead, is a nucleotide inihibitor which differs from nucleoside inhibitors like AZT, and has fewer side-effects. Phase II and III trials had been completed and the drug is available overseas, with no significant resistance being evident so far. |
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From left: Dr Rob Pawinski, Prof Jerry Coovadia, Dr Pravi Moodley and Dr Fanny Kiepiela
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