FIG. 5.

IFN-γ ELISPOT carried out using cultured PBMC obtained from volunteers in the 50-μg dose group 56 days after the first immunization (A) and 14 days after the second immunization (day 70) (B). IFN-γ SFC were measured following overnight incubation with recombinant proteins (ICC-1132, HBc, or rCS) or malaria CS peptides (T* or repeats). Due to the wide range of backgrounds in unstimulated wells obtained with cells from different volunteers (day 56 range, 24 to 384 SFC/10⁶ cells in unstimulated wells; day 70 range, 7 to 563 SFC/10⁶ cells in unstimulated wells), the results are shown as the increase (n-fold) in the number of SFC (mean SFC in triplicate wells with antigen divided by mean SFC in wells without antigen). Volunteers 16-C and 23-C were saline placebo controls.