The present invention relates to methods for the production of heat shock protein complexes for use in vaccine compositions. In particular, there is provided a method for increasing the level and immunogenicity of heat shock protein complexes produced in cells by subjecting the cells to specific stress inducing stimuli. The invention further extends to the use of heat shock protein complexes produced according to the methods of the invention in the preparation of vaccine compositions for the prevention and treatment of infectious diseases and cancerous conditions.
