The present disclosure provides methods for preparing vesicles. In one aspect, the methods involve providing a molten mixture of vesicle-forming lipids and adding the molten mixture of vesicle-forming lipids to an aqueous solution comprising an antigen such that antigen-containing vesicles are formed, wherein in the step of adding the molten mixture of vesicle forming lipids is at a temperature of less than 120° C. In another aspect, the methods involve providing a molten mixture of vesicle-forming lipids and adding an aqueous solution comprising an antigen to the molten mixture of vesicle-forming lipids such that antigen-containing vesicles are formed, wherein the resulting mixture is placed under temperature-controlled conditions of less than 60° C. In yet another aspect, the methods involve providing a solution of vesicle forming lipids and adding the solution of vesicle-forming lipids to an aqueous solution comprising an antigen by injection such that antigen-containing vesicles are formed.