The present invention is directed to methods of preventing reactivation ofactive and latent M. tuberculosis infections by administering a pharmaceuticalcomposition comprising a nucleic acid encoding a Mtb72f fusion protein, or aMtb72f fusion protein or an immunogenic fragment thereof, for example togetherwith an adjuvant. The Mtb72f nucleic acid or fusion protein can beadministered with one or more chemotherapeutic agents effective against a M.tuberculosis infection. The methods also provide for shortening the timecourse of a chemotherapeutic regimen against a M. tuberculosis infection.