The present disclosure provides methods for preparing vesicles. In general, these methods include steps of providing a lyophilized lipid product and rehydrating the lyophilized lipid product with an aqueous solution comprising an antigen such that antigen-containing vesicles are formed. The lyophilized lipid product is prepared by dissolving vesicle-forming lipids in a polar-protic water-miscible organic solvent to produce a lipid solution and then lyophilizing the lipid solution. The present disclosure also provides antigen-containing vesicle formulations prepared using these methods. The present disclosure also provides kits that include a lyophilized lipid product in a first container and an aqueous solution comprising an antigen in a second container.