Weekly Dosing of Malarone ® for Prevention of Malaria

Inclusion Criteria: * A male or non-pregnant, non-lactating female 18 to 50 years of age (inclusive) at the time of screening * Free of clinically significant health problems * Baseline ECG before entering into the study * Available to participate for duration of study (approximately 4 months, not including screening period) * If the participant is female, not pregnant or lactating and willing to use contraception to prevent pregnancy * BMI between 19 and 30 Exclusion Criteria: * History of malaria or travel to a malarious country within the previous 12 months * History of participation in a study in which potential exposure to malaria or vaccination against malaria occurred. * Planned travel to malarious areas during the study period. * History of malaria chemoprophylaxis within 60 days prior to time of study entry. * Chronic use of antibiotics with anti-malarial effects * Chronic use (defined as more than 14 days)of immunosuppressants or other immune-modifying drugs within six months of study entry. * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection * Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination, ECG or laboratory screening tests * Significant unexplained anemia * History of sickle cell disease or sickle cell trait * Seropositive for hepatitis B or hepatitis C * History of splenectomy * Pregnant or lactating female, or female who intends to become pregnant during the study * Suspected or known current alcohol abuse as defined by the American Psychiatric Association in DSM IV * History of a neuropsychiatric disorder (anxiety, depression, psychosis, schizophrenia) * Chronic or active illicit and/or intravenous drug use * History of allergy to atovaquone, proguanil or chloroquine * History of psoriasis * Concurrent participation in other research studies