Vaccine-naive individuals were randomly assigned to receive Ahnui vaccine with or without MF59 adjuvant in 1 of 5 doses ( 3.75 g [ n = 55 with MF59 and n = 59 without ] , 7.5 g [ n = 51 with MF59 and n = 57 without ] , 15 g [ n = 48 with MF59 and n = 44 without ] , 45 g [ n = 47 with MF59 and n = 47 without ] , or 90 g [ n = 57 without adjuvant ] ) or placebo ( n = 100 ) given at days 0 and 28 .