RecruitingScreening of Healthy Volunteers for Investigational Antimalarial Drugs, Malaria Vaccines, and Controlled Human Malaria ChallengeBackground: Malaria is a serious infection caused by a parasite. People get malaria when an infected mosquito bites them. Malaria can cause major health and social problems in places were malaria is common, such as Africa but can also affect travelers who have never been exposed to malaria. Researchers at the NIH want to find a safe and effective malaria vaccine, antimalarial drugs, or prevention regimen. To do this, healthy volunteers are recruited under a general screening study in order to see if are qualified to join a future malaria study. Objective: To screen healthy volunteers to see if they are eligible to join investigational malaria studies. The studies will be trials of investigational antimalarial drugs, malaria vaccines, or prevention regimens. They may also involve controlled human malaria infection trials. Eligibility: Healthy people ages 18 50 Design: Participants will first be prescreened by phone. Participants will be screened with: Medical history Physical exam Blood and urine tests Participants may go more than 1 year without joining a clinical trial. If this happens, they may be re-contacted to see if they still want to be part of this screening protocol. Those who still want to participate and have had relevant medical changes will be rescreened.