Patent ID: 6117449
Filing Date: 2000-09-12
Classification: A61K,C12N

Abstract:
A method for stimulating a systemic immune response to an antigen selected from the group consisting of hepatitis B and hepatitis C antigens in a mammal comprising:providing a liposomal preparation comprising lyophilized liposomes containing at least one antigen selected from the group consisting of hepatitis B antigens, hepatitis C antigens and mixtures thereof, wherein the liposomes have at least three different sizes before lyophilization and consist essentially of:at least 5% by volume, based on the total volume of liposomes in the preparation, small liposomes having a size, before lyophilization, of from about 20 nm to about 1 micron,at least 5% by volume, based on the total volume of liposomes in the preparation, medium liposomes having a size, before lyophilization, of from about 1 micron to about 3 microns, andat least 5% by volume, based on the total volume of liposomes in the preparation, large liposomes having a size, before lyophilization, of from about 3 microns to about 20 microns; andorally administering an effective amount of the liposomal preparation to a mammal,whereby sufficient antigen containing liposomes are absorbed in the Peyer's patches of the gut of the mammal and are taken up by macrophages in the Peyer's patches to stimulate a systemic immune response.