This is an open-label immunization with Controlled Human Malaria Infection (CHMI) study. Healthy, malaria-nave adults, aged 18-55 years old will be recruited into one of 5 experimental cohorts in 2 parts.

In Part A, 2 experimental cohorts of 5 subjects each will receive a series of 3 vaccinations at 0, 1, and 2 months at 2 doses (the "low dose" arm and the "high dose" arm).

In Part B, 3 experimental cohorts of 10 subjects will receive a series of 3 vaccinations at 0, 1, 6 months (called the "delayed dose" arm), the "delayed fractional dose" arm is vaccinated at 0, 1, and 6 months with the 6 month dose being 1/5 the other doses, and the "standard" arm" at the 4th, 5th, and 6th month (after the first 2 vaccinations of the other 2 arms in Part B).