The present invention aims to provide a vaccine pharmaceutical composition for transdermal administration which is safe, usable as a prophylactic or therapeutic agent for cancer or infectious diseases, and capable of safely and effectively inducing a systemic immune response. The present invention relates to a vaccine pharmaceutical composition for transdermal administration to be administered to a human or animal skin, the vaccine pharmaceutical composition including: a lipopolysaccharide derived from at least one 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 its salt as an immunostimulant； and at least one antigen, the vaccine pharmaceutical composition having a mass ratio between the immunostimulant and the antigen, the total mass of the immunostimulant/the total mass of the antigen, of 0.002 to 500.
