Provided is an allergy vaccine composition that is useful as a preventative or therapeutic agent for allergic diseases, is safe, and can effectively induce immunological tolerance. This allergy vaccine composition is administered to humans or animals that have an allergic disease in order to prevent or treat the allergic disease. The allergy vaccine composition is characterized by containing at least one type of allergen and, as an immunomodulator, at least one type of lipopolysaccharide derived from a Gram-negative bacterium selected from the group consisting of Serratia, Leclercia, Rahnella, Acidicaldus, Acidiphilium, Acidisphaera, Acidocella, Acidomonas, Asaia, Belnapia, Craurococcus, Gluconacetobacter, Gluconobacter, Kozakia, Leahibacter, Muricoccus, Neoasaia, Oleomonas, Paracraurococcus, Rhodopila, Roseococcus, Rubritepida, Saccharibacter, Stella, Swaminathania, Teichococcus, Zavarzinia, Pseudomonas, Achromobacter, Bacillus, Methanoculleus, Methanosarcina, Clostridium, Micrococcus, Flavobacterium, Pantoea, Acetobacter, Zymomonas, Xanthomonas, and Enterobacter, or a salt of said lipopolysaccharide.
