Analysis of the Immune Response to the Malaria Parasite in Mali, West Africa

This study will examine the immune response to the malaria parasite at the cellular level to better understand why people achieve natural immunity to the parasite only after multiple infections and why immunity diminishes rapidly in the absence of ongoing infection. The results of this study may provide insight into whether and how natural immunity can be improved upon by vaccination. Healthy people 2-4 and 18-25 years of age who live in the village of Kambila, Mali, may be eligible for this 1-year study. Participants have a small blood sample collected from a vein in the arm and also from two finger pricks at the beginning of the study, then every 2 months for 6 months and at the end of the study (for a total of five samples). People who become ill with malaria are evaluated and treated by a physician. Those recovering from their first episode of malaria during the study period have another blood sample collection and two finger pricks (bringing to six the total number of samples collected).