PROBLEM TO BE SOLVED: To provide a pharmaceutical technique which reduces an effective dosage amount of an oral vaccine containing as an active ingredient killed lactic acid bacteria which express a target antigen on the surface.SOLUTION: Provided is an oral formulation for prevention or treatment of the pathogen infectious disease, containing killed lactic acid bacteria which express a pathogenic antigen on the surface with a mean particle diameter of 2.68-30 &mu；m, or an atomized material thereof. Provided is an oral formulation for inducing cell-mediated immunity against the target antigen concerned, containing the killed lactic acid bacteria which express the target antigen on the surface with a particle diameter of 2.68-30 &mu；m, or an atomized material thereof.【課題】標的抗原を表面発現する死菌化乳酸菌を有効成分とする経口ワクチンの有効投与量を低減させる製剤技術を提供すること。【解決手段】平均粒子径２．６８～３０μｍの、病原体抗原を表面発現する死菌化乳酸菌又はその微粒化物を含む、当該病原体感染性疾患の予防又は治療のための経口製剤。粒子径２．６８～３０μｍの、標的抗原を表面発現する死菌化乳酸菌又はその微粒化物を含む、当該標的抗原に対する細胞性免疫を誘導するための経口製剤。【選択図】なし
