The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), recently awarded 14 contracts to fund the Large-Scale Antibody and T Cell Epitope Discovery Program. This initiative is designed to identify immune epitopes from selected infectious agents utilizing complementary methods for epitope discovery. NIAID will make information on each newly identified epitope freely available to scientists worldwide through the Immune Epitope Database and Analysis Resource (IEDB), currently under development. On October 12-14, 2004, representatives of NIAID met in San Diego, California, with a group of investigators from various research institutions to discuss progress and plans for the large-scale epitope discovery projects and for the establishment of the IEDB. It is anticipated that these initiatives will establish detailed maps of immune reactions toward several important complex pathogens, which in turn will foster development of new diagnostic, immune-based therapeutic, and vaccine programs. Herein is an account of the meeting and its results.