Chimeric proteins are expressed, secreted or released by a bacterium to immunize against or treat a parasite, infectious 
disease or 
malignancy. The delivery vector may also be attenuated, non-pathogenic, 
low pathogenic, or a 
probiotic bacterium. The chimeric proteins include chimeras of, e.g., phage coat and / or 
colicin proteins, bacterial toxins and / or enzymes, autotransporter peptides, lytic peptides, multimerization domains, and / or membrane transducing (ferry) peptides. The active portion of the immunogenic chimeric proteins can include antigens against a wide range of parasites and infectious agents, cancers, Alzheimer's and Huntington's diseases, and have enhanced activity when secreted or released by the 
bacteria, and / or have direct anti-parasite or 
infectious agent activity. The activity of the secreted proteins is further increased by co-expression of a 
protease inhibitor that prevents degradation of the 
effector peptides. Addition of an 
antibody binding or 
antibody-degrading 
protein further prevents the premature 
elimination of the vector and enhances the immune response.