The invention generally relates to soluble beta-glucan compositions and method of using such compositions. In one aspect, an adjuvant for a pharmaceutical composition is described which includes a soluble beta-glucan and a TLR agonist, each in an amount that, in combination with the other, is effective to increase a subject's immune response to an antigen. In another aspect, compositions that generally include an antigen component, a soluble beta-glucan component, and a TLR agonist component and a method that generally includes administering to a subject a composition that comprises a soluble beta-glucan and a TLR agonist, each in an amount that, in combination with the other, is effective to increase a subject's immune response to an antigen, are described.
