The invention relates to an agent for the treatment or prevention of an allergic condition, such as asthma, in a mammal. The agent comprises fragments of a Mycobacterium tuberculosis-complex (MTB-C) strain. These particular fragments may be from a virulent MTB-C strain and/or in the form of a liposome composition. The agent may include further components, such as a liposome-forming agent and/or particular proteins from the MTB-C strain. A particular allergic response that may be treated by the agent of the invention is allergic asthma. A pharmaceutical composition comprising the agent is also provided. Administration of the agent described herein significantly attenuates airway hyperresponsiveness, eosinophilia and lymphocytosis in the airways of sensitized animals. The effectiveness of the agent exceeds on all the evaluated parameters the commercial vaccine BCG Danish 1331 Strain.
