Provided herein are PEGylated liposomes, and methods of making and using thereof. The PEGylated liposomes comprise at least a cholesterol, a non-PEGylated neutral lipid, and a PEGylated lipid, wherein the average molecular weight of the PEG component in the PEGylated lipid is about 5000 Daltons or less. The PEGylated liposomes are stable and capable of delivery of an agent for the generation of an immune response, for example an agent for vaccine, therapeutic, or diagnostic uses. Compositions and methods related to making the PEGylated liposomes and using the PEGylated liposomes for stimulating an immune response are also provided.