Disclosed are compounds, compositions, and methods relating to epitope-targeted immunostimulants (EPIs), which comprise a synthetic peptide ligand and an antibody-recruiting moiety. The peptide ligand binds an epitope on a target and the antibody-recruiting moiety recruits antibodies to the target when the EPI is bound to the epitope on the target. Also disclosed are compositions comprising any of the disclosed EPIs. Also disclosed are methods of stimulating an immune reaction to a microorganism or other pathogen in a subject where an EPI is administered to the subject. Also disclosed are methods of identifying the peptide ligand by using multi-omic analysis.