Immunization Via Mosquito Bite With Radiation-attenuated Sporozoites

Inclusion Criteria: * Healthy adults (male or non-pregnant, non-breastfeeding female) 18-50 years of age (inclusive). * Available and willing to participate for duration of study. * Able and willing to provide written informed consent. * Able to complete an Assessment of Understanding with a score of at least 70% correct. * In good general health with no clinically significant health problems as established by medical history, physical exam and laboratory screening. * Females of childbearing potential must have a negative pregnancy test at screening and agree to not become pregnant or breastfeed for the duration of the study. She must be willing to use a reliable form of contraception during the study. Reliable forms of birth control include use of condoms, diaphragm or cervical cap, birth control pills, IUD or sperm killing products. * Agree to refrain from blood donation (except as required in this study) for 3 years following P falciparum challenge. * Agree not to travel to a malaria-endemic region during the study. * Good peripheral venous access. Exclusion Criteria: * Positive HIV, HBsAg, or HCV serology. * Positive sickle cell screening test, including evidence of sickle trait. * Reactivity by CSP or AMA1 ELISpot assay or ELISA as determined by IMRAS Study Specific Procedure #204. * Anemia (below normal reference laboratory value of hemoglobin) on screening. * Weight less than 110 pounds (this does not apply to infectivity controls as it is a weight cut-off for subje…