To overcome the limitations of the use of conventional liposomes chitosan coated egg yolk lecithin based liposomes were used as antigen carrier through parenteral administration in two animal models such as fish and rabbit. Extracellular proteins (ECPs) antigen of Aeromonas hydrophila encapsulated in liposomes became more stable and induced better immune response. It enhanced both adaptive and innate immune responses than other preparations both at 21,42 and 63 days post-immunization and suggested to be a better antigen delivery system. (C) 2011 Elsevier B.V. All rights reserved.