Selected PvDBP-derived synthetic peptides were tested in competition assays with HI-A molecules in order to identify and evaluate their binding to a wide range of MFIC class 11 molecules. Binding was evaluated as the peptide's ability to displace the biotinylated control peptide (HA(306-318)) and was detected by a conventional ELISA. Thus, one epitope for the HLA-DR1 Molecule, two epitopes for the HLA-DR4 molecule, six epitopes for the HLA-DR7 molecule and three epitopes for the HLA-DR1 I molecule displaying a high binding percentage (above 50%) were experimentally obtained. The in vitro results were compared with the epitope prediction results. Two peptides behaved as universal epitopes since they bound to a larger number of HLA-DR molecules. Given that these peptides are located in the conserved PvDBP region 11, they Could be considered good candidates to be included in the design of a synthetic vaccine against Plasmodium vivax malaria. (C) 2008 Elsevier Inc. All rights reserved.