Method to enhance an immune response of nucleic acid vaccination

A composition for generating an immune response in a mammal comprising liposomes associated with a nucleic acid encoding an influenza hemagglutinin (HA) antigenic protein and an influenza HA protein that shares at least one epitope with the encoded antigenic protein;

• wherein the nucleic acid and the influenza HA protein are associated with the same liposomes;
• wherein the nucleic acid is entrapped in the intravesicular space of the liposomes;
• and
• influenza HA protein in antigenic form is displayed on the surface of same liposome, and
• wherein the liposomes have an average diameter in the range of 100-2000 nm.

A composition for generating an immune response in a mammal, which composition comprises liposomes formed from liposome-forming materials and wherein said liposomes are associated with a nucleic acid and an assistor protein,

• wherein the nucleic acid operatively encodes an antigenic protein or portion thereof which shares at least one epitope with the assistor protein,
• the liposomes having an average diameter in the range of 100-2,000 nm, which liposomes are not polymerized and are based substantially on phospholipids,
• wherein the nucleic acid encoding said antigenic protein and the assistor protein are associated with the same liposomes;
• the antigenic protein and the assistor protein are from an infectious agent;
• the nucleic acid is entrapped in the intra vesicular space of the liposomes;
• the assistor protein in antigenic form is displayed on the surface of the same liposome;
• the liposomes lack any further cell targeting moiety;
• the liposomes include at least one cationically charged component such that the liposomes have an overall positive charge;
• the nucleic acid and the assistor protein are present in a weight ratio in the range of 1,000:1 to 1:1.