Grand Challenges is a family of initiatives fostering innovation to solve key global health and development problems. Each initiative is an experiment in the use of challenges to focus innovation on making an impact. Individual challenges address some of the same problems, but from differing perspectives.
In the developing world, many people with health problems never receive an accurate diagnosis or appropriate treatment because clinicians lack tools to detect and diagnose diseases and conditions quickly, accurately, and inexpensively. Sophisticated medical tests that could help improve care are not only often unaffordable, they require extensive laboratory facilities and deliver results days later - a hardship for people who may live many miles from the nearest health clinic. Dr. Kelso's team is developing rapid, affordable, point-of-care systems for both immunological and molecular tests. The project's objective is to design low-cost delivery platforms that can perform assays in resource-poor settings.
The current vaccine against bacterial pneumonia (pneumococcus) requires a regimen of four injections given at specific intervals. In developing countries, this not only complicates the vaccination process for health workers and children, but it also is a serious obstacle for families who must travel long distances to the nearest health clinic. Dr. Curtiss and his colleagues are working to develop new vaccines against bacterial pneumonia that require only a single dose, can be delivered orally, and are safe for newborns, infants, and people who are malnourished or whose immune systems are compromised.
To develop new vaccines against some of the world's biggest killers, including HIV, malaria, and tuberculosis, scientists must be able to evaluate promising candidates. Some of the most promising potential vaccines, are made from weakened live versions of the infectious agent. As a result, they cannot be studied in human trials unless researchers can be confident that the weakened vaccines will be safe. Dr. Flavell and his colleagues are working to genetically engineer laboratory mice whose immune systems are similar enough to humans to permit testing of vaccines against diseases that disproportionately affect people in the developing world. Flavell (Grand Challenges in Global Health: 2005-2015 retrospective)
In the developing world, lack of convenient and accurate tools that can detect and diagnose diseases and other health problems means that many health risks remain undetected or receive inappropriate treatment. Dr. Yager's team, in collaboration with research groups from private industry as well as the nonprofit sector, is working to develop a low-cost, easy-to-use device that will rapidly test blood for a range of health problems prevalent in developing countries, such as bacterial infections, nutritional status, and HIV-related illnesses.
Attenuated vaccines, composed of weakened organisms incapable of causing disease, provide prolonged exposure to antigens and have proven effective against several viral or bacterial diseases. Dr. Kappe's team is attempting to extend this concept to a malaria vaccine. In the case of malaria, disease develops when the malaria sporozoite – the form of the parasite that is transmitted from mosquitoes to humans – enters the bloodstream and moves to the liver. There, it grows and divides into thousands of parasites that invade and destroy red blood cells, causing disease. Dr. Kappe's team is working toward development of a malaria vaccine using a malaria sporozoite that has been weakened by gene deletion to stimulate immune response. Kappe (Grand Challenges in Global Health: 2005-2015 retrospective)
To maintain stability and viability, most childhood vaccines must be kept cool - both heat and freezing can ruin them. That means they must be refrigerated at the correct temperature throughout transportation, storage, and delivery. This cold chain is difficult and costly to maintain, especially in developing countries. Dr. Sonenshein and his team are working to create childhood vaccines for diphtheria, tetanus, and pertussis (the DTP combination vaccine), and rotavirus-related diarrhea that can withstand a wide range of temperatures without refrigeration by encapsulating them in harmless bacterial spores that are naturally heat-resistant.
Tuberculosis (TB) is a major health problem, especially in developing countries. Dr. Kaufmann is leading an international consortium that is studying differences in immune system responses between people exposed to TB who never become sick and those who develop the disease, focusing particular attention on people infected with both HIV and TB in endemic African countries. The project's participating laboratories in Europe and the United States are attempting to learn which host responses provide protective immunity against TB and to identify correlates of protective immunity and host biomarkers of TB disease that could help guide the design and testing of improved TB vaccines, drugs, and diagnostics.
A subset of women who apparently are resistant to HIV infection may provide scientists with the genetic and immune system information they need to advance vaccine and drug development. Since 1985, investigators have tracked groups of commercial sex workers in Kenya who do not become infected with HIV despite repeatedly having sex without condoms. If investigators can understand what constitutes and results in protective immunity against HIV, they may be able to replicate it through vaccines. Dr. Plummer's team is conducting an exhaustive analysis of the immunologic and genetic factors that mediate HIV resistance in the women, with the goal of gaining a more complete understanding of what constitutes protective immunity against HIV infection.
Dr. Fraser's team is working to develop and test new approaches to suppressing the replication of dengue virus in the cells of its primary vector, Aedes aegypti mosquitoes. The team is using genetic strategies to introduce a molecular mechanism that uses the dengue virus' own genetic make-up to initiate a process that results in the death of infected cells in the mosquitoes, limiting their ability to transmit disease. In addition, investigators are working on tools to enhance the application of this and other genetic strategies in mosquitoes.
In the developing world, infections in the respiratory and intestinal tracts are major causes of sickness and death, especially among children. Vaccine delivery systems that can target respiratory or intestinal mucosal tissue and stimulate immune response there have the potential to be particularly effective against these infections. Dr. Lo's project addresses two needs: the development of vaccine delivery systems that do not require needles and the design of systems that target specific tissues in the body. Using influenza vaccination as a model, Dr. Lo and his team are working to bind vaccine to specially designed molecules that target mucosal tissue.