An antigen-containing formulation is provided, comprising: (a) an antigen; (b) a TH1-inducing adjuvant; and (c) a sparingly soluble amino acid or a derivative thereof. The adjuvant may be, for example, monophosphoryl lipid A, 3′-de-O-acetylated monophosphoryl lipid A, derivatives thereof, or any other adjuvant that enhances an individual's TH1 response to the antigen. Suitable amino acids include tyrosine, tryptophan, derivatives thereof, and the like. Methods for using the formulation are also provided; in a particularly preferred embodiment, the formulation is used as a vaccine.