Cohort 1 hyperimmunized subjects: IFN-γ, IL2 and IFN-γ+IL2 responses to sporozoites, CSP, AMA1, TRAP and CelTOS.

IFN-γ, IL2 and IFN-γ+IL2 responses of four subjects protected to CHMI#1 were measured after post-5th (5) immunization, 39–41 days post-CHMI#1 (Post-C#1), 27 weeks post-CHMI#1/pre-boost (PreB), post-1st boost (B1), post-2nd boost (B2), post-3rd boost (B3) and 15 weeks post-CHMI#2 (Post-C#2). Responses to sporozoites: three high responders (C1p1 stars; C1p2 rounded squares; C1p4 crosses) and one low responder (C1p3 double circles); geometric mean of sporozoite responses (red bar); numbers at top of Panel are % positive subjects. *Only 3 subjects (C1p2; C1p3, C1p4) were tested at these time points. Panel A: IFN-γ responses: sporozoites: IFN-γ responses declined by 27 weeks after CHMI#1/pre-boost but rose post-1st boost and were then largely unchanged. Panel B: IL2 responses: sporozoites: IL2 responses followed the same pattern as IFN-γ responses. Panel C: IFN-γ+IL2 responses: sporozoites: IFN-γ+IL2 responses disappeared by 27 weeks after CHMI#1/pre-boost, and slowly rose post-1st, and post-3rd boosts and post-CHMI#2. Responses to antigens: CSP (diamonds), AMA1 (triangles), TRAP (squares) and CelTOS (circles). Panel D: IFN-γ: only one subject (C1p3) had a positive IFN-γ response to AMA1 by 27 weeks post-CHMI#1/pre-1st boost; post-1st boost and post-2nd boost IFN-γ responses to individual antigens rose. Panel E: IL2: no subjects had IL2 responses to any antigen by 27 weeks after CHMI#1/pre-1st boost; post-1st boost and post-2nd boost IFN-γ responses to individual antigens rose.