BUILDING BRIDGES, DISMANTLING WALLS
Seth Berkley
The development of a vaccine to prevent HIV infection is one of the most daunting scientific challenges of our time. Yet, for all its complexity, this field of research seeks to answer a relatively simple question: how do you get the immune system to detect and disable HIV before it has a chance to insert itself into the human genome and establish an intractable infection? Most vaccines against viruses, such as those that prevent measles and polio, do so by teaching the immune system's B cells to generate neutralizing antibodies - exquisitely targeted protein missiles that bind to invading pathogens and tag them for destruction. HIV, however, is no ordinary adversary. It has evolved multiple strategies to flummox the immune response. Not least among these is a nearly unparalleled mutability that has vexed vaccine designers for the better part of three decades.
Any vaccine devised to seriously curb the AIDS pandemic will, at a minimum, have to protect against those HIV subtypes that predominate in developing countries, where some 90 percent of new infections occur. It should also thwart multiple variants of those viruses. This poses extraordinary scientific and logistical challenges. But it also has significant implications for the policies that guide and shape AIDS vaccine research and development. First, it requires that candidate HIV vaccines be tested in developing countries, which entails the establishment of the requisite human resources and technical capacity in such places. Second, in light of the unique scientific challenges of AIDS vaccine development, funders and policymakers need to find ways to encourage innovation and the application of hitherto untapped technologies to solve the toughest problems in the field. Finally, global efforts to develop AIDS vaccines would benefit from greater participation from the private sector. The market disincentives and risks - most prominently high failure rates and opportunity costs - inherent to HIV vaccine development have traditionally discouraged industrial participation. But appropriate incentives and funding policies could do much to change that.
