 Methodology The design was a single blind, randomized, placebo controlled, dose-escalating study involving 46 healthy Caucasian volunteers aged 18-45 years. Five groups of 8 subjects received virosomal formulations containing 10 ug or 50 ug of AMA 49-CPE, an apical membrane antigen-1 AMA-1 derived synthetic phospatidylethanolamine PE-peptide conjugate or 10 ug or 50 ug of UK39, a circumsporozoite protein CSP derived synthetic PE-peptide conjugate or 50 ug of both antigens each. A control group of 6 subjects received unmodified virosomes. Virosomal formulations of the antigens designated PEV301 and PEV302 for the AMA-1 and the CSP virosomal vaccine, respectively or unmodified virosomes were injected i. m. on days 0, 60 and 180. 