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Summary

Malaria, which had been eliminated or effectively suppressed in many parts of the world, is undergoing a resurgence. It is a public health problem today in more than 90 countries inhabited by some 2,400 million people—40 percent of the world's population. Malaria is estimated to cause up to 500 million clinical cases and 2.7 million deaths each year (WHO, 1996). Every 30 seconds, a child somewhere dies of malaria. The global effects of the disease threaten public health and productivity on a broad scale and impede the progress of many countries toward democracy and prosperity (Oaks et al., 1991).

The United States is not immune to the growing threat of malaria (Lederberg et al., 1992). The increasing number of U.S. citizens traveling and residing abroad, including military personnel, are at growing risk of serious disease and death from malaria. In addition, the toll of the disease in the developing world restricts regional economic development and impedes development of global markets for U.S. goods and services.

The outlook for malaria control in the face of this deteriorating situation is grim. The continuing emergence of drug resistance in the malaria parasite and the widespread insecticide resistance of the mosquitoes responsible for transmitting the disease have reduced the selection of tools to control malaria— there are fewer options available now than there were 20 years ago. There is widespread agreement, however, that vaccines against malaria would be a cost-effective public health tool to reduce the burden of disease and will be an essential component of successful control of the global threat. The impressive strides made in the field of malaria research in the past 15 years provide compelling reasons to believe that a malaria vaccine is a biotechnological and immunological possibility. In spite of growing scientific optimism, however, the pace of vaccine development appears to be slowing because of diminishing public funds, fragmented public sector efforts, and limited interest within the vaccine industry.

PROJECT CHARGE

In view of the deteriorating global malaria situation and the urgent need for new and effective control measures, the IOM was asked by a consortium of



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Vaccines Against Malaria: Hope in a Gathering Storm 1 Summary Malaria, which had been eliminated or effectively suppressed in many parts of the world, is undergoing a resurgence. It is a public health problem today in more than 90 countries inhabited by some 2,400 million people—40 percent of the world's population. Malaria is estimated to cause up to 500 million clinical cases and 2.7 million deaths each year (WHO, 1996). Every 30 seconds, a child somewhere dies of malaria. The global effects of the disease threaten public health and productivity on a broad scale and impede the progress of many countries toward democracy and prosperity (Oaks et al., 1991). The United States is not immune to the growing threat of malaria (Lederberg et al., 1992). The increasing number of U.S. citizens traveling and residing abroad, including military personnel, are at growing risk of serious disease and death from malaria. In addition, the toll of the disease in the developing world restricts regional economic development and impedes development of global markets for U.S. goods and services. The outlook for malaria control in the face of this deteriorating situation is grim. The continuing emergence of drug resistance in the malaria parasite and the widespread insecticide resistance of the mosquitoes responsible for transmitting the disease have reduced the selection of tools to control malaria— there are fewer options available now than there were 20 years ago. There is widespread agreement, however, that vaccines against malaria would be a cost-effective public health tool to reduce the burden of disease and will be an essential component of successful control of the global threat. The impressive strides made in the field of malaria research in the past 15 years provide compelling reasons to believe that a malaria vaccine is a biotechnological and immunological possibility. In spite of growing scientific optimism, however, the pace of vaccine development appears to be slowing because of diminishing public funds, fragmented public sector efforts, and limited interest within the vaccine industry. PROJECT CHARGE In view of the deteriorating global malaria situation and the urgent need for new and effective control measures, the IOM was asked by a consortium of

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Vaccines Against Malaria: Hope in a Gathering Storm U.S. federal and private sponsors to conduct a workshop to evaluate current international efforts in malaria vaccine research and development and to make recommendations on how the U.S. federal government can help expedite more rapid and efficient development of promising malaria vaccine candidates. To accomplish this task, the IOM convened the Committee on Malaria Vaccines, a group of six members reflecting a broad range of expertise in microbiology, parasitology, vaccine research and development, molecular biology, epidemiology, and the conduct of vaccine field trials and related issues. The committee met on 7 July 1995 to review the project charge and develop the agenda for the international workshop. The workshop, which was subsequently held on 19–20 October 1995 in Washin, D.C. (see the Appendix for the agenda), addressed two key questions: what are the current incentives and disincentives to fuller participation of the industrial sector in malaria vaccine development, and how can the U.S. federal and industrial sectors and the international community work together more efficiently toward the common goal of developing effective malaria vaccines? This report summarizes the findings of the 19–20 October 1995 workshop. ORGANIZATION OF THE REPORT The report contains six chapters and one appendix. Chapter 1 summarizes the findings and recommendations of the workshop. Chapter 2 provides an overview of the global extent, causative agents, and mode of transmission of malaria; the health impact of malaria on the U.S. population; the economic and developmental impact of malaria; current strategies for malaria control; the rationale for developing a malaria vaccine; and the goals and target populations of malaria vaccine efforts to date. Chapter 3 focuses on the scientific and organizational elements that are in place and provides a rationale and basis for accelerated malaria vaccine development. Chapter 4 describes the current scientific and organizational obstacles that need to be addressed in developing a coherent plan of action, and Chapter 5 and Chapter 6 offer ways to surmount these obstacles. The Appendix provides the workshop agenda. FINDINGS AND RECOMMENDATIONS Workshop participants agreed that the successful development and widespread application of a vaccine that can prevent the illness and death of malaria could be one of the most important advances in medicine, with the potential for improving the lives of hundreds of millions of people. The successful completion of this task, however, will require an extraordinary level of effort in the scientific, public health, and industrial sectors, as well as coordination of these efforts. The following findings and recommendations of

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Vaccines Against Malaria: Hope in a Gathering Storm the Committee on Malaria Vaccines are based on the evidence and testimony presented at the October workshop and are offered as a basis for coherent and focused action. Findings Malaria is the most prevalent vector-borne disease in the world. It causes up to 500 million clinical cases each year. Given the importance of malaria and the shortcomings of antimalarial drugs and vector control, vaccine development merits a high priority. A malaria vaccine is feasible. Malaria research over the past two decades has produced a compelling body of evidence demonstrating protective immunity in small animals, primates, and man. Antigens potentially involved in protective immunity have been identified in all stages of the life cycle of the malaria parasite. Although thus far it has proved difficult to elicit solidly protective vaccine immunity, related research on vaccine delivery and adjuvants, in conjunction with advances in malariology, provide the rational basis for a new, accelerated vaccine development effort. An effective malaria vaccine will most likely consist of multiple genes/antigens and a novel adjuvant or delivery system. It will likely require multiple sophisticated and proprietary technologies, which must be accessible for public sector use, while protecting industry's return on investment. Two types of vaccines are envisioned, each with different characteristics and prospects for development. The first vaccine is needed to provide long-term protection against disease and to reduce mortality among children in endemic areas of the world. The second vaccine is needed to induce shorter-term, but highly protective, immunity in nonimmune adult travelers entering highly malarious (endemic) areas. Successful development of malaria vaccines will require the collaborative efforts of government, academia, and industry. Each sector has unique capabilities to contribute, but the public sector must take the lead, given the costs of vaccine research and development and present beliefs that expected returns on investment will cover only a portion of the research and development outlay. The pharmaceutical and biotechnology industries must play a major role in resolving technical issues relating to appropriate expression and purification of antigens, vaccine formulation, and manufacturing technology, but new industrial development efforts will come only in conjunction with a successful, coordinated public sector effort that first proves the feasibility and value of a given technical approach. A coordinated strategy for vaccine development, focusing on a limited number of development options, is essential. The high cost of producing and testing an experimental vaccine mandates a focus on a limited number of the most promising vaccine candidates.

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Vaccines Against Malaria: Hope in a Gathering Storm Testing a successful malaria vaccine in the field can be readily accomplished and is no more difficult than the field testing required for most other vaccines against infectious agents. Mechanisms such as the African Malaria Vaccine Testing Network are currently in place to allow field trials to be conducted in an efficient and cost-effective manner in areas of high endemicity. Market forces for developing malaria vaccines are potentially vigorous and are growing on a global scale, but they are not yet fully appreciated or understood. For potential industrial developers to make appropriate decisions or choices, analyses of potential markets for each type of potential vaccine candidate must be undertaken, and the results made widely available to interested parties in all involved sectors. Recommendations A federal “Malaria Vaccine Development Board” should be established and given the responsibility, authority, and resources to carry out the strategy or strategies most likely to result in accelerated, successful development of malaria vaccines. The board should include representatives from academia, relevant federal government agencies, pharmaceutical and biotechnology companies, and foundations. A crucial initial task of the board would be to identify and focus U.S. development efforts on a limited number of the most promising malaria vaccine candidates. The board should monitor progress in malaria vaccine development in both the public and private sectors; identify development needs, opportunities, and priorities and advise interested parties and funding agencies of these findings; provide financial and other support for high-priority development efforts; and encourage collaboration among academia and private and public sector entities. To succeed, the board must have the following attributes: access to sufficient resources to fill gaps in the malaria vaccine development process in a timely manner; a sustained, long-term commitment to malaria vaccine development; the ability to access all phases of the malaria vaccine development process, through field implementation of immunization programs; the flexibility to address rapidly changing needs, technologies, and priorities in the field of malaria vaccine development; the ability to access, in a cost-effective manner, optimal technologies and developmental expertise in either the private or the public sector; and the ability to provide the leadership in conducting U.S. malaria vaccine development efforts and in coordinating these with international academic researchers, corporations, and relevant organizations such as the

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Vaccines Against Malaria: Hope in a Gathering Storm World Health Organization, the World Bank, the United Nations Development Programme, and the Commission of the European Communities. While there are historical precedents for aspects of the proposed Malaria Vaccine Development Board, none completely covers all of the facets described above. Some examples of precedents that may be examined for relevance to elements of the board include the 1941 Commission on Influenza of the Armed Forces Epidemiology Board, the National Task Force on AIDS Drug Development, and the National Foundation for Infantile Paralysis. The board should commission independent market analyses to assess potential global markets—both private and public—for each of the types of malaria vaccine. These analyses should be conducted by country or region, both in the industrialized and developing world, and findings made available to the global vaccine industry.