Phase I Study of AMA1-C1/Alhydrogel® (Registered Trademark) + CPG 7909 Malaria Vaccine

This study will evaluate the safety and immune response of healthy volunteers to an experimental malaria vaccine called AMA1-C1/Alhydrogel® (Registered Trademark) + CPG 7909. Malaria is an infection of red blood cells caused by a parasite, Plasmodium falciparum, that is spread by certain kinds of mosquitoes. Each year, about 1 million people are killed by malaria worldwide, most of them young children in Africa. AMA1 C1 may help block the malaria parasite from getting into red blood cells. The vaccine is mixed with Alhydrogel® (Registered Trademark), a material that is commonly added to vaccines to make them work better (also called an adjuvant). Besides evaluating the vaccine, this study will also test two solutions of an experimental adjuvant, CPG 7909-P and CPG 7909-S. Healthy people between 18 and 50 years of age may be eligible for this 7-month study. Participants are randomly assigned to one of four treatment groups (A, B, C or D below). All receive two vaccinations, given as a shot in the upper arm either 1 or 2 months apart, as shown: * Group A: AMA1 CI/Alhydrogel® (Registered Trademark)/CPG 7909-P at Day 0 and Day 28 (1-month interval) * Group B: AMA1 CI/Alhydrogel® (Registered Trademark)/CPG 7909-S at Day 0 and Day 28 (1-month interval) * Group C: AMA1 CI/Alhydrogel® (Registered Trademark)/CPG 7909-P at Day 0 and Day 56 (2-month interval) * Group D: AMA1 CI/Alhydrogel® (Registered Trademark)/CPG 7909-S at Day 0 and Day 56 (2-month interval) Group A and B participants return to the clinic for checkups at 3, 7, and 14 days after each vaccination and again at months 2, 3, 4, 5, and 7. Group C and D participants come to the clinic at 3, 7, and 14 days after each vaccination and again at months 3, 4, 5, and 7. In addition to the vaccinations, the study includes the following procedures: * Photographs of the subject's arm where the vaccination is given if a rash develops. * Daily temperature and symptoms record for the first 6 days after each of the 2 vacci