The present invention relates to the use of an immunotherapeutic agent having cell wall fragments of a virulent strain of Mycobacterium tuberculosis for the preparation of a drug suitable for the primary prophylaxis of tuberculosis. The immunotherapeutic agent is capable of inducing a protective response that is more effective than the conventional BCG vaccine and reduces the number of viable bacilli in the lungs and in the spleen of individuals recently infected by M. tuberculosis.
