Evaluation of 5.1-[NANP]19, a recombinant Plasmodium falciparum vaccine candidate, in adults.

In a randomized single-blind study, 13 healthy adult volunteers were subcutaneously immunized with 2 or 3 single 50 or 400 μg doses of a Plasmodium falciparum recombinant vaccine candidate designated 5.1-[NANP] 19 . The vaccine caused trasitory reactions at the injection site. Eight (62%) volunteers had a≥ 4-fold increase of antibody titer against sporozoites in immunofluorescence assay, all 13 seroconverted in IgG enzyme-linked immunosorbent assay against [NANP] 50 antigen, and in 6 (46%) a lymphocyte proliferation index ≥3 against 5.1 antigen was observed