Lack of protection afforded by ribonucleic acid preparations from Mycobacterium tuberculosis against Mycobacterium leprae infections in mice

Abstract
Mycobacterial RNA preparations from H37Ra, an attenuated strain of M. tuberculosis, provide their usual marked protection against M. tuberculosis challenge; they provided no protection against M. leprae challenge. Suspensions of intact H37Ra were not effective against M. leprae. Suspensions of BCG gave their usual distinct protection against M. leprae challenge.