A vaccine containing Mycobacterium bovis BCG which secretes a fusion protein to be obtained by inserting a foreign antigen peptide into the molecular surface of a secretory protein, a carrier, having a signal peptide. BCG constituting the present invention secretes a fusion protein to be obtained by inserting a foreign antigen peptide into the molecular surface of an .alpha.-antigen derived from mycobacteria. Said fusion protein has significantly increased antigenicity and immunogenicity. Therefore, when it is inoculated into animals, it is efficiently recognized by B cells which recognize said antigen, thereby effectively inducing the production of an antibody to said antigen. When said BCG itself is inoculated into animals, it continuously secretes said fusion protein in the bodies of the animals while continuously propagating therein. Therefore, said BCG is an extremely useful vaccine.