Vaccine constructs, doses, and times of immunization.

Trial 1: Dose escalation study: Group 1 was immunized with a single dose, a safety review was conducted, then Group 2 was immunized with a single five-fold higher dose. Results are presented in the companion publication, Sedegah et al. Trial 2: Challenge study. Group 3 was immunized twice using the Group 1 dose of CSP, with 15 weeks between doses. Fifteen volunteers received the first dose, 14 volunteers the second; data for all 29 immunizations are included in the safety analysis. Twelve volunteers underwent malaria challenge 21 days following the second immunization; one of the 12 was later excluded from the analysis of immunogenicity and protection due to the discovery of prior participation in another malaria challenge trial.