Adjuvants for anti-parasite vaccines

To date the most successful human vaccines use attenuated living pathogens, but the advent of techniques in genetic engineering has meant that pure antigen can be provided in quantity. This has allowed the development of combined vaccines that use only the parasite antigens that convey protective immunity. However, isolated antigens lose immunogenicity so to regain potency, living attenuated carriers like Vaccinia or Salmonella can be used. To avoid the attendant drawbacks of carriers as immunopotentiating agents, adjuvants are under investigation as alternatives for use in vaccines against parasitic infections. In this review, Robert Bomford describes the adjuvants currently being examined for use in vaccines for both protozoan and helminth infections including Leishmania, malaria and Schistosoma. He also points out the drawbacks of using adjuvants and the dilemma of needing to stimulate cell'-mediated immunity while avoiding the immunopathological consequences of doing so.