Abstract: The present invention is directed to methods of preventing reactivation of active and latent M. tuberculosis infections by administering a pharmaceutical composition comprising a nucleic acid encoding a Mtb72f fusion protein, or a Mtb72f fusion protein or an immunogenic fragment thereof, for example together with an adjuvant. The Mtb72f nucleic acid or fusion protein can be administered with one or more chemotherapeutic agents effective against a M. tuberculosis infection. The methods also provide for shortening the time course of a chemotherapeutic regimen against a M. tuberculosis infection.