Phase I Study of IMP321 Given Alone or as an Adjuvant to a Reference Flu Antigen

This study is a single centre, single blind, placebo (step 1) or reference (step 2) randomised study. Healthy young male volunteers will receive single ascending dose of IMP321 in each step (4 doses tested: 3, 10, 30 and 100 µg). In step 1, IMP321 will be given alone and tested versus placebo (physiological saline). In step 2, the association IMP321 + Agrippal (commercially available flu vaccine) will be tested versus Agrippal alone.