A vaccine formulation as disclosed which is comprised of a pharmaceutically acceptable carrier in a plurality of particles with mannose on their surface. The particles are comprised of a biocompatible polymer which maybe a co-polymer such as PLGA combined with a peptide of a sequence which corresponds to a sequence on a surface of a pathogen. A plurality of different groups of particles are provided in the formulation wherein the particles within any single group include peptides of identical amino acid sequence. The particles are sized such that they are sufficiently large so as to prevent more than a single particle from being presented to a single immune system cell.