Cationic liposomes with entrapped polynucleotide in the intravesicular
space are described. The liposomes include cationic components such as
cationic lipids such as DOTAP. Preferably the method of forming liposomes
uses the dehydration-rehydration method in the presence of the
polynucleotide. The polynucleotide preferably operatively encodes an
antigen capable of eliciting a desired immune response, that is, is a
gene vaccine.