Re-formulation of selected DNA vaccine candidates and their evaluation as protein vaccines using a guinea pig aerosol infection model of tuberculosis

Summary A selection of previously identified protective Mycobacterium tuberculosis DNA vaccines were re-formulated as proteins and administered with a Th1-inducing adjuvant to help stimulate the relevant immune responses necessary for protection. All three candidate-vaccines conferred high levels of antigen-specific cellular and humoral responses, as indicated by lymphocyte proliferation and serum IgG levels. Protective efficacy was also assessed in comparison with the current vaccine, BCG (the ‘gold-standard' against which new vaccines are tested), and a saline (negative) control. One candidate (Rv1806-1807) induced protection in the guinea pig aerosol infection model 30 days post-challenge on the basis of reducing the bacterial burden of M. tuberculosis in the lungs.