Abstract: A vaccine produced in edible plant and/or animal products, as well as a method of second-generation vaccine development through the production of at least one complete structure of a pathogen in a transgenic plant or animal is described. Preferably, the present invention enables the production of virus-like particles in edible food plants, through the co-expression of a plurality of proteins and/or of a plurality of portions of such proteins. The co-expression of viral structural proteins should enhance the immunogenicity of the transgenic antigen by providing all elements necessary to induce a protective immune response. In one variation of the method the immune response to the transgenic vaccine would be induced by presenting the transgenic proteins as part of an edible plant structure, utilizing this to stimulate the mucosal immune system. Alternatively, the vaccine produced in transgenic plant/animal products could be purified and used as an immunogen in other vaccination strategies.

Abstract: A method for administering the HAV vaccine to a subject by absorption through a mucosal tissue, particularly through the mucosa of the rectum. The method of the present invention enables the HAV vaccine to be administered to the subject rectally, for example as a suppository or other rectal dosage form, and to successfully immunize the subject against HAV. Thus, the present invention overcomes problems of background art methods of administration, such as systemic administration by injection for example, which require needles, and which are difficult and expensive to perform.