Skin patches (20) having a microprojection array (10), a reservoir (18) containing an antigenic agent and an immune response augmenting adjuvant, and methods of using same to vaccinate animals (e.g., humans) is disclosed. In a preferred embodiment, the microprojection arrays (10) are composed of a photoetched and micro-punched titanium foil (14). The microprojections (12) are coated with a liquid formulation containing a vaccine antigen and an adjuvant such as glucosaminyl muramyl dipeptide, dried, and applied to skin of the animal to be vaccinated using an impact applicator. The microprojections (12) create superficial pathways through the stratum corneum to facilitate permeation of antigenic agent and adjuvant. Antigen dose and depth of penetration can be controlled. This technology has broad applicability for a wide variety of therapeutic vaccines to improve efficacy, and convenience of use.