Vaccines for Parasitic Infections

Abstract

Publisher Summary This chapter discusses vaccines for parasite infections. It has been reported that in many parasitic diseases more information is required to identify those proteins that should be included in a subunit vaccine. This is especially true for those parasites having many stages with different antigens, each inducing a complex immune response. Often the required step that has proven difficult to accomplish in the past is the purification of antigens from parasites for testing. The methods of recombinant DNA technology at present allow this obstacle to be overcome readily by overexpression in prokaryotic or eukaryotic systems, or even to be totally by-passed using viable recombinant vectors for immunization rather than purifled antigens. One may be encouraged that in some diseases, such as malaria, anaplasmosis, and babesiosis, parasite antigens which are immunoprotective have been purified. The protection engendered, although significant, has not always been as effective as using viable parasites. In these diseases, the main challenge is to develop optimal methods of antigen presentation to induce cell-mediated and humoral immunity as necessary. Cloning of genes for these immunoprotective proteins at present allows testing of the most effective methods of presentation, which could be considered the second stage of vaccine development. The availability of live bacterial and viral vectors offers exciting possibilities for combining the advantages of live vaccines with those of single, purified antigens.