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Barcelona 2002: Taking Stock of the Epidemic

By Patricia Kahn and Emily Bass

In the high-stakes world of AIDS research, two years can bring distinct shifts in priorities and paradigms.

And every 24 months, the Olympic-sized International AIDS Conference provides an opportunity to assess and reflect on these changes.

 

This year's Conference in Barcelona will undoubtedly take measure of the progress in AIDS since Durban 2000, the landmark gathering which focused the world's attention on the devastating epidemic in the global South. It will find a landscape changed in many ways—along with some discouragingly familiar constants.

Durban became a crucial turning point in mobilizing global commitment to fight HIV/AIDS in Africa, and in acknowledging the world's dismal failure to do so thus far. It also helped catalyze an emerging consensus that real progress will demand not only a massive scale—up of efforts and funds, but a more broad—based approach that recognizes the inexorable link between prevention and treatment, and that brings new sectors—from government finance ministries to international development agencies and business—into a battle that had been left mostly to public health agencies and affected communities.

This was also the view from the 2001 United Nations General Assembly Special Session on HIV/AIDS (UNGASS). The first UN session of its kind devoted to a public health issue, UNGASS concluded with a strongly—worded declaration promising intensified efforts in AIDS prevention, care, support and human rights protection for infected people and affected communities. At the same time, UN Secretary General Kofi Annan called for the creation of the Global Fund to Fight AIDS, TB and Malaria, an initiative which has so far brought US$2 billion in new resources to spend on the major diseases of poverty.

But in spite of these steps, there are sobering distances still to be covered. AIDS continues to spread relentlessly, not only in its established strongholds of sub—Saharan Africa and the Caribbean nations but in new regions and populations. For example, the world's fastest growing HIV epidemic in 2001 was in Russia and other regions of Central Asia, while the burgeoning number of newly-infected people in South Asia—home to about half the world's population—could outnumber that in sub-Saharan Africa within the decade if unchecked. On a political level, the world has not yet committed the resources needed to achieve the ambitious goals declared at Durban and UNGASS. Antiretroviral treatment and even rudimentary care remain out of reach to most of the world's people living with HIV/AIDS, and new prevention strategies have yet to emerge.

Another key issue voiced at Durban is the need to balance present and future priorities. In practice this means reducing HIV spread through existing means and caring for those already infected, while at the same time mobilizing funds and political will for the vaccines and microbicides that will save future generations.

For AIDS vaccines, the past two years have brought growing support and scientific activity—although a successful vaccine is probably at least five years away (if the ongoing VaxGen trial does not show efficacy of the AIDSVAX® vaccine). And there are no guarantees of success. Some highlights since Durban:

  • Several vaccines have moved (or soon will) into Phase I clinical trials, while Merck's DNA/adenovirus-based approach and Oxford/Nairobi/ IAVI's DNA— and MVA—based vaccines are entering expanded Phase I/II studies.
  • In addition to Merck, GlaxoSmithKline has an HIV vaccine in Phase I testing, while Wyeth-Lederle, Chiron, Aventis Pasteur and several small biotech companies are developing their own candidates.
  • VaxGen's ongoing Phase III trials in Thailand, North America and Europe have passed the halfway point and should yield first results early next year. Whatever results the vaccine itself shows, these trials have demonstrated the feasibility of running large, ethical AIDS vaccine studies in high-risk populations.
  • Developing country involvement is growing. Kenya, Trinidad and Tobago, Haiti and Brazil are now conducting Phase I or II trials, and several other countries—including South Africa, India, China, Côte d'Ivoire and several Latin American nations—have launched vaccine programs. Uganda, which ran Africa's first AIDS vaccine trial in 1999-2000, has* several trials in the cards.
  • A second AIDS vaccine approach (Aventis Pasteur's canarypox plus VaxGen's gp120) will soon enter Phase III testing in Thailand. But many of the biggest challenges in developing an AIDS vaccine still lie ahead. There are many scientific unknowns. There is a great need to get safe, promising products into efficacy trials as soon as possible, and to build capacity for conducting these trials in countries highly affected by HIV/AIDS. And it is urgent to lay the policy foundations for making an effective vaccine widely available as soon as one is licensed. As with the AIDS field overall, Durban also marked a broadening of the vaccine effort, with more governments, businesses and other new players from different parts of the world becoming engaged alongside the scientists, health workers and communities who are developing and testing vaccine candidates.

This issue of the IAVI Report highlights a few examples. We begin with a look at the field of female microbicides, which is now moving several products into later-stage testing (and has completed one Phase III study) in several African countries. In getting this far, it has already amassed valuable experience in running clinical trials that involve women at high risk for HIV-experience that also offers important lessons for vaccines.

In another example, we report on a community-led initiative to start an AIDS vaccine trial site in southern Brazil. It's something of a "tail-wags-dog" scenario, since trial sites nearly always begin with researchers, institutions and/or funders providing the first impetus and only then approaching the community. From India, a country with an estimated 3.9 million HIV-infected people, comes news of a recent gathering that brought together Parliamentarians and policymakers—along with both the Prime Minister and opposition party leader, an almost unprecedented double-bill—to take a closer look at AIDS vaccine development and the experiences of other developing countries already planning or conducting trials.

On the scientific front, we look at two difficult areas. Guest contributor Chris Beyrer, an AIDS epidemiologist and Southeast Asia expert, writes about HIV spread among injecting drug users (IDU), a key factor in most epidemics outside Africa. He argues that vaccines must be tested in both IDU and sexually-transmitting populations if we are to ensure that these products will work against both routes of infection. And he presents examples of willing, engaged IDU cohorts—starting with the Bangkok VaxGen trial population—and of potential new IDU trial sites that suggest these studies should be feasible. There's also a short report on a new IAVI-backed initiative to boost research into one of the toughest, most elusive tasks facing AIDS vaccines: how to induce antibodies that neutralize a broad range of HIV isolates.

Turning to the broader vaccine landscape, we speak with Tore Godal of the Global Alliance on Vaccines and Immunization (GAVI). Godal discusses some of GAVI's "lessons learned" from its first round of funding programs to vaccinate more children in the world's poorest countries against basic childhood diseases. And he describes the emerging political commitment across the world to make these vaccines available to all.

The search for an AIDS vaccine is proving to be long and frustrating. Success will take vision, scientific breakthroughs and mobilization of far more resources than are now available. But perhaps at the International AIDS Conference in Bangkok 2004, we will look back on Barcelona as the event that catalyzed a new level of funding and commitment, in keeping with the scale of the epidemic.