lations, for measuring the risk of exposure for human populations, and for monitoring epidemiologic parameters in human populations (e.g., malaria antibodies, malaria antigens, and drug use) in country-wide efforts to improve malaria management capabilities.

Vector-related issues assume great importance as candidate vaccines move from laboratory testing to field evaluation. Baseline information on both the intensity and seasonality of transmission is necessary for planning vaccine trials. During vaccine field trials, concurrent measurements of sporozoite challenge (EIR) will be useful for gauging vaccine efficacy, especially in large trials conducted at sites with different transmission intensities.

RESEARCH FOCUS: Site-specific characterization of malaria transmission by vector populations before vaccine field trials and concurrent efforts to monitor transmission intensity during field trials.

Transmission-blocking vaccines are being developed to elicit human antigametocyte antibodies that block early stages of parasite development in the mosquito. Such vaccines, when used in a mixture with other vaccines, may extend their effective life by reducing the rate at which variant forms of parasites appear. Both naturally occurring and laboratory-generated transmission-blocking antibodies are usually tested by mixing sera containing antibodies with malaria parasites and assessing the development of oocysts in the vector. It is difficult to predict the potential efficacy of transmission-blocking vaccines because the extent to which antigametocyte antibodies regulate vector infectivity in nature has never been determined in focused studies on vector populations.

RESEARCH FOCUS: Field studies to assess natural effects of transmission-blocking antibodies on the early stages of parasite development in vector populations.

Malaria parasite development in anopheline vectors is a complex process that takes 8 to 15 days from the ingestion of gametocytes to the appearance of sporozoites in the salivary glands of the mosquito. Regula-

Front Matter (R1-R18)

1. Conclusions and Recommendations (1-21)

2. Background (22-36)

3. Overview (37-55)

4. Clinical Medicine and the Disease Process (56-72)

5. Diagnostic Tests (73-89)

6. Parasite Biology (90-117)

7. Vector Biology, Ecology, and Control (118-143)

8. Drug Discovery and Development (144-168)

9. Vaccines (169-210)

10. Epidemiologic Approaches to Malaria Control (211-236)

11. Economics of Malaria Control (237-256)

12. Social and Behavioral Aspects of Malaria (257-278)

Appendix A: Paradigms (279-282)

Appendix B: Dissenting Opinion (283-288)

Glossary (289-296)

Index (297-310)