The 2014/15 influenza season in Spain was dominated by drifted A(H3N2) virus.
The influenza vaccine effectiveness was low against influenza A(H3N2) and moderate against B virus.
The influenza vaccine effectiveness decreased in late epidemic stage and with time since vaccination.
The decrease of IVE was slower and milder against influenza B than against influenza A(H3N2).
We highlight the importance of the influenza vaccination especially in population risk groups.