Abstract: The disclosure provides compositions that include microparticles or nanoparticles of beta inulin or inulin acetate and an active agent, where the active agent is contained within individual microparticles or nanoparticles. The active agent can be, for example, a vaccinating antigen, an antigenic peptide sequence, or an immunoglobulin. The compositions can be incorporated into various formulations for administration to a subject such as a human or animal. The invention further provides methods of using the compositions and formulations, including methods of stimulating an immune response in a subject, or enhancing an immune response in a subject, for the purpose of treating, preventing, or inhibiting an infectious disease, autoimmune disease, immunodeficiency disorder, neoplastic disease, degenerative disease, an aging disease, or a combination thereof.