The invention relates to the use of an immunotherapeutic agent containing cell wall fragments of a virulent strain of Mycobacterium tuberculosis- complex (MTB-C) for the preparation of a drug for the prophylactic treatment of tuberculosis, in which said agent can be obtained using a method comprising the following steps: cultivate the virulent MTB-C strain over a period equal to or greater than three weeks； and, subsequently, homogenate the cell culture in the presence of a nonionic surfactant.
