The invention relates to the use of a trivalent, non-live influenza antigen preparation, particularly a split influenza preparation, in the manufacture of a one-dose influenza vaccine for intradermal delivery. In particular the invention relates to the use of spilt influenza preparations wherein the vaccine comprises at least one non-ionic surfactant selected from the group consisting of the octyl- or nonylphenoxy polyoxyethanols (for example the commercially available TritonTM series), polyoxyethylene sorbitan esters (TweenTM series) and polyoxyethylene ethers or esters of general formula (I): HO(CH2CH2O)n-A-R wherein n is 1-50, A is a bond or-C(O)-,R is C1-50 alkyl or phenyl C1-50 alkyl and combinations of two or more of these.
