Developing an AIDS vaccine that will prevent HIV from establishing infection in a healthy immune system is a daunting enough challenge. But some researchers are working on what is almost certainly an even more formidable undertaking-developing therapeutic vaccines that are intended to boost the immune response to HIV in people who are already infected.
AIDS vaccine research has long been seen as having scant overlap with treatment for people infected with HIV. But in 2003 several major AIDS vaccine trial sponsors effectively redrew the boundaries between the fields of AIDS vaccines and treatment with announcements that they would work to ensure the availability of antiretrovirals (ARVs) for volunteers who become infected through high-risk contact, such as unprotected sex, during the course of an AIDS vaccine trial.
The recent decisions by several AIDS vaccine trial sponsors to ensure access to antiretrovirals (ARVs) for trial participants who become infected with HIV come after years of debate and discussion about the ethical implications of providing-or not providing-these powerful medications to trial volunteers. Two of the central questions were: Is there an ethical obligation to provide ARVs to volunteers who become infected during the trial period through high-risk behavior?
I'm writing to say adieu from my perch at the IAVI Report. In August 2003, after three years as editor of the newsletter, I left IAVI to resume freelance writing, editing and teaching.
Mauro Schechter MD, Ph.D is one of the leading figures in the field of AIDS in Brazil, and his renown now spreads beyond his home country to the international sphere. He is Head of the AIDS Research Laboratory at the Universidade Federal do Rio de Janeiro, and was one of the first Brazilian scientists to commit to setting up a preventive AIDS vaccine clinical trial site, as well as being instrumental in setting up the first Community Advisory Board in the country.
For the better part of the 20th century, vaccine development and testing was the province of the industrialized world. Many of today's vaccines, including those against polio and measles, were licensed based on data from efficacy trials in the United States and Europe.
HIV is famously the most genetically diverse viral pathogen known—nowhere more so than in Africa—as well as one of the most rapidly mutating. That, plus the uneven global distribution of its nine genetic subtypes, or clades, poses one of the biggest scientific unknowns facing AIDS vaccine developers: is a single, “universal” vaccine against all strains possible?
Australian Consortium Launches DNA-Fowlpox Trial; New Proposal for a Global AIDS Vaccine Enterprise; African AIDS Vaccine Programme Meets in Ethiopia; First HIV vaccine trialS get green light in South Africa
Philip Berman, developer of VaxGen's gp120-based AIDSVAX® vaccine, gave a much-anticipated talk on the outcome of the company's North America/Europe Phase III trial. It was the first presentation of the trial's efficacy results to a scientific audience, following a 24 February webcast describing the initial analysis.
Since launching its first HIV vaccine clinical trials in 1999, Merck has emerged as a major player in the field, with over 600 people now enrolled in its preventive vaccine studies. So far the company has focused on two candidates—one based on naked DNA, the other on a vector made by modifying adenovirus-5 (Ad5), a common virus that causes colds in humans. Both vaccines exclusively target the cellular immune system.
Although DNA-based vaccines are beingdeveloped against many diseases, results in humans have not lived up to the initial promise shown in animal models. By themselves they are usually poor inducers of antigen-specific immunity; as the first of two vaccines in a prime-boost combination—the most common way to use DNA vaccines—the jury is still out, although Merck’s data on DNA/Adenovirus5-based vaccines in humans so far are disappointing.
When data from VaxGen’s completed AIDSVAX® trial were released in February, the media flurry focused on the efficacy results, which were disappointing. Nearly lost in the shuffle were the trial’s unqualified successes with recruitment and retention. Here, data refuted pre-trial concerns about the feasibility of following thousands of high-risk volunteers over three years and seven immunizations.
Do vaccines work differently in men and women? Over the past few years, this question has been transformed from a far-flung supposition to a serious query for HIV vaccine researchers, even cropping up in the recent analyses of VaxGen data.
The choice to use-or not use-condoms impacts enormously on women's risk of acquiring HIV. But it is possible that other methods of contraception could also impact women's susceptibility to HIV-for better or for worse. For example, new studies are looking at whether the diaphragm reduces HIV acquisition risk by covering the cervix, a site that is particularly vulnerable to infection. And there is a large body of data, much of it contradictory, on how hormonal contraceptives (HCs) might affect acquisition of HIV.
On 27 March 2003, the European Parliament endorsed the creation of an Africa-based clinical trials program to test new medical products targeting AIDS, malaria and tuberculosis. The endorsement came with €€200 million in direct funding from the "Sixth Framework Programme," the European Union's (EU) research strategic plan for 2002-2006, and an expectation that another €400 million will be contributed over this timeframe through in-kind support from national programs and additional donations from industry, member state governments, multilateral agencies and other sources.
At the last two International AIDS Conferences, the Canadian HIV/AIDS Legal Network has co-sponsored workshops ("Putting Third First") that have been widely recognized for bringing together AIDS advocates from diverse fields, including microbicides, vaccines and treatment. The common ground is a human rights-based approach, which argues that international statutes are important tools for advancing treatment and prevention agendas. Australian-born David Patterson was a founding member of the Network in 1992 and is now its director of International Programs and Capacity Building.
This January's World Economic Forum (WEF) meeting in Davos, Switzerland featured a three-hour workshop on "The Economic Impact of HIV/AIDS." Led by IAVI CEO Seth Berkley, participants considered best- and worst-case scenarios for government and industry responses to HIV/AIDS in the next decade.
In January 2003, Ian Gust took over from Jaap Goudsmit as chair of IAVI's Scientific Advisory Committee (SAC), which helps guides ongoing projects and future initiatives. The SAC is composed of 12 experts in AIDS vaccine development and related fields, and has three sub-committees: Vaccine science, project management and clinical trials.
On 29-31 January, the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) held its fourth Board meeting in Geneva, Switzerland. At the meeting, US Secretary of Health Tommy Thompson was approved as the new GFATM Chair, replacing Ugandan health minister Chrispus Kiyonga. Suwit Wibulpolprasert, Deputy Permanent Secretary for the Thailand Ministry of Health, was elected as Vice Chair.
With this issue of the IAVI Report we introduce a new feature aimed at keeping readers informed about the growing activity in clinical testing of HIV vaccines. "Clinical Trials Watch" will track ongoing trials, starting with the complete listing below and providing future updates on their progress, along with information on newly-launched studies. The table also includes several trials due to start in the first quarter (Q1) of 2003.
From 27-29 October 2002, about 200 scientists gathered in Annecy, France for the "13th Cent Gardes Symposium on HIV and AIDS Vaccines." Meeting for the first time in this scenic Alpine town, the symposium still bears the name of its original home outside Paris—the historic building where Napoleon III once housed his elite troop of bodyguards, the "Cent Gardes," and Louis Pasteur later maintained his animal laboratories.
The Global Alliance for Vaccines and Immunization (GAVI)1 was founded almost 3 years ago to reinvigorate basic vaccination coverage as a central element of sustainable development in poor countries. From 19-21 November 2002, over 300 participants from developing nations, donor agencies, industry and NGOs gathered for the second GAVI Partners meeting in Dakar, Senegal, to review progress, identify challenges and discuss ways forward.
This October, the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF) co-sponsored its second meeting on HIV vaccines and immunoprophylaxis in infants.* Held in Seattle, the 2002 gathering shared a location—and many participants—with the biannual meeting of the HIV Vaccine Trials Network (HVTN).
On 18-20 November 2002, regulators and Institutional Review Board (IRB) members from 14 southern African countries met with officials from the World Health Organization (WHO), researchers, and others working on HIV vaccine and microbicide development to discuss regulatory issues in the region.* The workshop, held in Gaborone, Botswana, built on two previous WHO regulatory meetings in Geneva and Villars-sur-Ollon, Switzerland. It was the first gathering in the series to take place in Africa, and the first to focus on specific regional challenges.
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This information is designed to support, not replace, the relationship that exists between you and your doctor.