Table 2. Antigen-specific ex vivo ELISpot IFN-γ responses of RAS-immunized subjects targeting novel P. falciparum antigens.

		Protected Subjects			Non-Protected Subjects
		v30	v58	v64	v20	v43	v52	v53
Pf clone	Peptides	A02/A03	A02/A03	A02/A03	A02/A03	A03/A26	A0103/A03	A01/A02
		B07/B44	B07/	B07/B27	B44/B62	B62/	B07/	B07/
Pf02	A02	18	5	13				33
Pf08	A02	1	13	0			0
Pf09	All					10		5
	A02	0	20	0				18
	B07	18	3				20
Pf26	All	15	28	13		3	20	5
	B07	0	18				8	48
Pf56	All	0	5	8	0	0	0	18
	A01					33		20
	B62				27	0
Pf61	All	8	18	3		0	18	5
	A02	5	25	5	23
	A03		40
Pf78	B07	1	12	0			0
Pf84	All					3	0	8
	A02	23	8	5		18		0
Pf93	All	4		1		8	3	0
Pf106	All		38	15	38	15
	A02	15	15	18	28
	B07	15	35				5
Pf116	All	0	25	0		0	0	0
	A02	0	25	13	13
Pf119	All	3		0		0		0
Pf121	A03	8	25
Pf144	A02	15	8	15
	A03	30	15	13		15		28
	B07	45	35				5	0

Peptide pools containing 15mer overlapping peptides spanning the full length (All) or predicted HLA-specific regions were tested in triplicate with pre-immunization and post RAS-immunization (pre-challenge) PBMCs. Numbers are the average of triplicate assays as sfc/m. Positive responses (in bold and larger font size) were defined as a difference of 20 sfc/m between pre- and post-immunization. Only peptide pools recalling positive responses are included. Antigen-specific cell responses exceeding the positive criteria in at least one volunteer were detected in response to stimulation by nine of 14 novel P. falciparum antigens using total or HLA-specific peptide pools. Since responses were low, cultured ELISpot IFN-γ responses were measured (Table 3).