CD8A and malaria: This trial confirms other studies demonstrating the safety and tolerability of adenovector vaccines in the 1×1010−1×1011 pu dose range, provides additional evidence of the potency of adenovectors for inducing CD8+ IFN-γ responses targeting malaria antigens in humans, suggests that a second dose does not enhance the immunogenicity of a first dose, and that CSP does not offer significant protection when delivered by itself using an Ad5 platform.